Comment - Stuff You`ll Find Here

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Author
Steve Frost
Comment
"Flat tops" vs arched bracing
Lead
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Tags : None
(01/23/07 3:08
PM)
I've been under the impression that Gibson always used a radius on their top braces, while Martin originally
used straight braces to produce a true "Flat-top", until at some point they switched over to the current 28'
radius top. I've posed the question before on other forums, and never got a definitive answer. What's the real
story on this?
Re: "Flat tops" vs arched bracing
Arnoldgtr
(01/23/07 5:55
PM)
#1
[-]
I believe Gibson started radiusing their top braces around 1935. I also believe that Martin has always used
radiused top bracing, but is is difficult to determine exactly how much. Over the years, the combination of
shrinkage and string tension tends to flatten the tops in the soundhole-bridge area.
Also, Martin has always clamped the top braces flat, relying on the resilience of the spruce to spring back into a
curve once the gluing is done.
One other change that Martin has done in recent years has to do with the way the sides are profiled where the
back joins. Today, you see a lot more longitudinal curvature of the back, resulting in deeper sides in the waist
area. This is a 'modern' guitar building technique, where the profile is generated with a large radiused sanding
dish.
Although a back with a constant spherical radius is easy to generate, it is not traditional.
John
Steve Frost
(01/23/07 8:54
PM)
BHguitars
#2
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Thanks, John- as I said, it was an impression, and I have no idea where I might have gotten it. I built my first
guitars using Irving Sloan's and David Russell Youngs books. Sloan used a truly flat top, and Young advocated
the domed top. I know I'm not telling you anything new, but mention it just for general illumination. Sloan
seemed to be traditional, versus some of Young's more "radical" ideas. So, perhaps I assumed that the dome
was the modern method. Thanks for the information! Does anyone have a figure for the Martin arch radius?
Just curious.
#3
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Quote:
I believe Gibson started radiusing their top braces around 1935
(01/24/07 2:56
AM)
Correct. While those pre '35 had a less arch the typical Gibson arch started with the beginning of the
codeletters meaning in 1935. But the pre' 35 Gibsons already had an arch although this did not include the
Author
Comment
important place around the sound hole and above the bridge.
Quote:
I also believe that Martin has always used radiused top bracing, but is is difficult to determine exactly how
much
I double this basically also but in my opinion Martin gained top arch more in using humidity and moderate heat.
While humidity always was (and still is) a big matter especially while bracing a guitar at Martin the tops were
stored dry and put next to the heating stove before braced. The top grain shrinks before the braces are glued
on first. Now when normal humidity returns the grain swells back somewhat and results in a slight top arch.
Additional this treatment prevents from future dryness cracks. This technique is old and widely used at
manufacturers (even at cabinet making these days) working with hide glue. The Spanish guitar makers at
example hang up their tops before they are braced on a line right under the ceiling near the heating stove
where the dehumidifying is working the best.
I have noticed that Martin tops have a different top arch depending on the season they were build. While
winter guitars have a better arch summer guitars mostly are flat and show more often a subsidence between
bridge and sound hole. This is also an indication for the "humidity" arch technique rather than the radiused
brace technique at old Martins. I'm sure that Gibson heated or dried down their tops as well additional.
Quote:
Today, you see a lot more longitudinal curvature of the back, resulting in deeper sides in the waist area. This is a
'modern' guitar building technique, where the profile is generated with a large radiused sanding dish.
This technique is a result of mass production. While old Martins mostly had a nice uniform back arch with
raised waist Gibson didn't pay attention to the waist area of the back. The result is a less longitudinal arch in
general but not uniform as consequence. At the waist there is much more arch crosswise while the lower bout
shows very little arch only.
But surprisingly the back arch at nicely arched '30s Martin backs is crosswise nearly the same than lenghtwise .
Willi
Steve Frost
#4
[-]
Were these Martins built with their kerfed linings beveled slightly to facilitate joining the arched braces to a
level rim? Trying to get an image of this. Is that what's going on with the Huss & Dalton TDR series?
(01/24/07 10:49
PM)
Author
Comment
#5
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Quote:
BHguitars
(01/25/07 2:33
AM)
Were these Martins built with their kerfed linings beveled slightly to facilitate joining the arched braces to a
level rim?
Steve,
I'm not sure if I understand correct. Do you mean if the kerfing matches the arch of the braces and the arch of
the back? Yes. When the kerfing has been glued to the sides and are levelled for the back they will follow the
back arch. Same is with the top side kerfing and with the top bracing. Also the main braces will be tucked or
mortised into the kerfing with an exact cutout for the braces. The back of the kerfing could be left with its glue
surface to the sides. This way the brace ends are locked in and won't get loose. The brace ends shouldn't hit
against the sides directly since when the arch will move down a little because caused by low humidity you
wouldn't want to find the braces to be pressed against the sides.
Willi
#6
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Quote:
But surprisingly the back arch at nicely arched '30s Martin backs is crosswise nearly the same than lengthwise .
Arnoldgtr
(01/25/07 3:22
AM)
Willi, that has not been my experience. I use side profiles from prewar Martins, and they don't have enough
'rise' in the waist area to produce a spherical arch. I have checked the back arches on many prewar Martins,
and I have yet to find one that has a true spherical arch. They generally have the most curvature across the
waist area, less curvature across the lower bout, and even less curvature longitudinally.
If you look at modern Martins, you will see what I am talking about. Virtually all modern Martins have a much
more pronounced longitudinal curve in the back when viewed from the side. This is because the sides are
deeper in the waist area, necessitiated by the increased curvature produced by the concave sanding disc.
If you don't have a new Martin in hand, you can look at the side views of new Martins on the Martin website.
Martin used to bevel the kerfing to match the back curvature by using a block plane. An arching template is laid
across the kerfing to 'eyeball' the arching angle. I still use this method, because I don't believe in the spherical
arch, for several reasons.
Here are the radii that I use:
Top = 25 feet
Back, longitudinal = 20 feet
Back, lower bout (wide braces) = 18 feet
Back, waist brace = 15 feet
Back, upper brace = 25 feet
Author
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This produces a 'fair curve' when coupled with older Martin side profiles. The back is fairly flat in the upper
bout, which results in more stability for the neck block.
John
#7
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Quote:
Arnoldgtr
(01/25/07 3:39
AM)
Is that what's going on with the Huss & Dalton TDR series?
I believe that Huss & Dalton (like today's Martin) uses the concave sanding disc to arch the linings and profile
the sides. This is what I mean by a spherical arch, where the radius is constant over the entire surface.
The problems with a spherical arch in the back are threefold:
1) It doesn't take into account the anisotropic nature of wood. Wood shrinks and swells across the grain, but
very little along the grain. This means that the back arch needs to be more across the grain, so that the back can
rise and fall when the moisture changes. A flat back will crack or sink concave if it shrinks.
2) A back with too much longitudinal arch will cause a shift in the neck block angle when the moisture changes.
This will change the neck angle, requiring frequent action adjustments.
3) A spherical surface is the most resistant to vibration.
John
#8
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Quote:
BHguitars
(01/25/07 4:13
AM)
If you look at modern Martins, you will see what I am talking about
John,
Sure, I know. I have seen such machines but also I guess the contemporary use of tall lower bout back braces
benefit a more pronounced arch especially at the lower bout. We also use various arching templates (I guess
every small maker does?) for various arches and cross and lenghtwise arches.
We recently checked over the side template for our 12 fret 0 size and so I re-checked some Martin back arches
of various 0, 00 and 000 size Martins I had at hand. All differed less or more but I also found some really fine
uniform arches length and crosswise with no bump . I'll see if I can get some pics later to demonstrate. I believe
the less of back arch at the lower bout depends on the use of the flat back braces that keep the arch solid but
slightly less curved than tall braces.
Willi
Author
Comment
Steve Frost
(01/25/07 9:28
AM)
John Platko
#9
[-]
According to their website, Huss & Dalton uses 2 styles of guitar construction, one that dishes the top and back
rims to a radius, and their traditional series: "Our Traditional series features the same 25' radius prepared into
the braces, but the sides are left flat for a more traditional build style. This build style tends to have a more
traditional tonal character, emphasizing a bit more bass."
BTW, I have no connection to H & D, never seen one, though they look very nice.
This is interesting, because in the builders forums that I frequent, nobody's really talking about this. The
prevailing attitude seems to be that if you're not sanding your rims on a radius dish, you're missing the bus.
Maybe not!
John and Willi- thanks for your perspective. Most of us don't have direct access to these vintage instruments,
especially to the insides, so this is a priceless opportunity. Thanks!
Hey- Where's Henk? I figured he'd chime in by now.
#10
[-]
Great thread!
Does anyone know where and when the concave sanding dish started to be used? When did Martin start using
it?
(01/25/07 11:50
AM)
Side profiles would be great to see Willi. I'd be especially interested in a OO-14 fret side profile.
#11
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Quote:
FoolForWood
Hey- Where's Henk? I figured he'd chime in by now.
Sorry Steve, it's a great thread but I just overlooked it.
This topic is so big, I don't know where to start.
(01/25/07 2:54
PM)
Mmm, let's do Huss and Dalton first.
In the GAL magazine some years ago, I read something that puzzled me. There was an interview with the guys
and the top arching was discussed. Here's my problem.
Author
Comment
Normally, all other things being equal, the stronger the arch (no extra mass but a stiffer top), the less bass. So if
you want more low oomp, you'd increase the radius (=less arch). H&D use a 25 ft radius for their top bracing
(rounder than a Martin), and the tops are glued to the sides after these have been sanded in a 25 ft concave
dish. So, the fit should be perfect.
But they also have a traditional line of guitars. Here you would expect them to use flatter braces and a less
concave dish, or a more traditional method altogether. However, what they do is the following. They use the
exact same tops (with the 25 ft radius bracing) and glue them to a flat plane rim. You now have to force the top
to adapt to the different shape. This will cause extra stress (I think they even call it "pre-stressing"). I would
expect that this extra stress will cost bass response. However, they claim that these guitars sound MORE bassy,
and closer to the original Martin sound. I'm not saying this can't be true, but if it is true, I would like to know the
physics behind it. (Does the middle part of the top get a more efficient spring function, like the diving board
that needs a firm base? Just a wild guess.)
Henk
#12
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Quote:
they don't have enough 'rise' in the waist area to produce a spherical arch.
BHguitars
(01/25/07 4:01
PM)
John,
I'd like to pick this up for some further discussions ... later. I don't find enough time now. Top and back arch,
arch profile and side shape are big matters at construction in general. Everybody has his own understanding
and interpretation what works best. Even my partner Rudie and I have somewhat different opinions in this
matter and discuss this often. But to demonstrate some details here are some pics. To sort arches one could list
as follows:
1. The arch itself
2. Different arches at different places
3. Ratio between cross and lenghtwise arch
4. Side profile at the waist
The pics show a typical but stronger Gibson back arch of a '39 Recording King Ray Whitley. I used a simple tool
that is easily adjusted for different arches. This is only to check out and to compare arches and their ratio at
different places. Here I adjusted the tool similar to what the back arch lenghwise could be:
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Clicke here for large image
Large image
Same tool adjustment at the lower bout:
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Large image
... at the waist:
Large image
... upper bout:
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Large image
Now the pics show following:
1. Gibson usually does not have a strong back arch. This one is more pronounced than usual. Especially
longitudinal it is stronger than most Jumbo bodies I have seen.
2. Adjusted the tool according the longitudinal arch the lower bout crosswise is slightly more arched. Not
shown is the arch near the 4th back brace were it is less than crosswise. At this place the longitudinal arch
shows a lowering. The waist shows an incredible strong arch. The upper bout is less arched and lousy looking
like the back of a camel but is also sunken in. Compare to the longitudinal arch. This is also the reason because
of slab cut wood.
3. The ratio lengthwise to crosswise is a stronger allover as it is typical for Gibson back arches.
4. It is visible nicely what John and Henk described above concerning the waist. The waist height stands in
relation to the back arch crosswise at the waist but also lenghtwise. Gibson does not care much about this so
the backs often have a "strange" arch. The waists are not raised, the short waist back brace shows a bigger arch
but often the arch lenghtwise at the waist is sunken in meaning either the arch at the waist is too small or the
waist not high enough.
There are other concepts of back arches and side profiles like vintage Martin or Larson. Larson is very
interesting since they seem to be the inventor of the steel string guitar top (and back) arch. Meaning Larsons
have a pronounced arch of both, top and back with raised waists at the sides for top and back. This construction
is considered (by some people) to be the earliest and best arch construction. But as I said: to be discussed ...
More later,
Willi
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#13
[-]
"Fascinating", Mister Spock would say. What I see in the pics is much like what beginning luthiers tend to
overlook, especially if they don't use the right books or teachers. I'm not a luthier so maybe I should hush, but
I've seen quite a few guitars made by beginners with the same mistakes. What happens is this. They brace the
back, all four braces with more or less the same arch. Transverse braces only, so the result is a cylindrical arch.
(Even if it would approach a spherical arch, there's still the same possible problem, although a little less
pronounced). Then they taper the sides, let's say from four inches at the heel to almost five at the tail. But no
curve! Just like e.g. luthier Donald Brosnac "teaches" in his handbook on steel string guitar construction. Of
course there's a bad misfit now. The tighter the waist, the stronger the misfit, as the sides should be
considerably taller in the waist area. They'll have to apply some serious force to glue the pieces together, and if
they succeed the back will have a considerably stronger arch in the waist area. If they also forget to bevel the
linings and the bottom of the blocks (heel especially), you'll get some odd shapes.
FoolForWood
(01/25/07 5:27
PM)
It's almost unbelievable that the Gibson seems to show some of the beginners mistakes. Pictures can be
deceiving, and in wide angle and/or close up mode straight lines outside the centre usually show some convex
distortion. But on my monitor, the second pic shows an almost dead straight back taper (side view of the
binding where it borders the side wood). It seems no wonder the crosswise arch is strongest at the waist.
On the other hand the lengthwise arch looks quite fair, apart from the heel area (which can be flattened by
almost seventy years of string pull). So perhaps they did compensate somewhat by giving the middle braces a
stronger arch.
The nice thing about spherical arches and sanding dishes for the sides (and braces) is that the fit is always
perfect. But, as John pointed out, there may be other things to consider. A more traditional way is shown in
Cumpiano and Natelson's book "Guitarmaking". Here they start out with a preliminary arch that is nicely
smoothed out.
Another neat way is how a friend of mine does it. A little difficult to explain, but I'll try. First, he braces the
(slightly oversized) back with arched braces. It is now curved crosswise, but not much lengthwise. He then
places a stiff stick or small beam over the centre backstripe and ties it to the back with rubber bands. Next he
puts wedges (small blocks wiil do, too) at the ends of the back, between the stick and the back. This forces the
back into a semi-parabolic shape. By choosing different thickness blocks, or simpler, by just sliding them a little,
he adjusts the curve to his liking. The arch in both directions is now set. He then places the back with stick etc.
on the guitar's (untapered) sides. The soundboard is faced down, of course. He lifts the back at the tail's side to
create the amount of taper he wants and puts a spreader block between back and tailblock. Then with a
spacer/spreader (?) and white pencil he traces the exact arch plus taper in one go onto the sides. After sawing,
the only thing that is not perfect yet is that the linings are still flat. But with a little experience this shouldn't be
a problem to fix.
Quote:
I use side profiles from prewar Martins, and they don't have enough 'rise' in the waist area to produce a
spherical arch.
Author
Comment
Quote:
Virtually all modern Martins have a much more pronounced longitudinal curve in the back when viewed from
the side. This is because the sides are deeper in the waist area, necessitated by the increased curvature
produced by the concave sanding disc.
Most modern manufacturers shape the sides BEFORE bending. This leaves very little sanding off to do by the
dished rotating sanders. When you look at these sides before they are bent, they show a very irregular shape
with strong bulge in the waist area. The experts already know this, of course, but I just wanted to make this
extra clear for all interested readers. A nice experiment for those who don't have anything better to do is
this:
Put a piece of paper over the sides of your guitar. Follow the curves and make sure the paper protrudes the
back and top. Then, with a pencil, track the perimeter of the top and back onto the paper (as close to the
binding as possible). Then look at the result and you'll know what we're talking about. Narrow waisted
(modern) instruments will show more spectacular results, but dreads will make it clear, too.
Good luck!
Henk
#14
[-]
Quote:
Arnoldgtr
They (H & D) use the exact same tops (with the 25 ft radius bracing) and glue them to a flat plane rim. You now
have to force the top to adapt to the different shape. This will cause extra stress (I think they even call it "prestressing" . I would expect that this extra stress will cost bass response.
I have always used this technique. It is MHO that this pre-stressing is a temporary effect that is minimized a
short time after the guitar is strung. Besides, all arched backs are 'pre-stressed' when they are glued to the
body, since the cross bracing does nothing to generate a longitudinal arch.
(01/25/07 5:52
PM)
Quote:
they claim that these guitars sound MORE bassy, and closer to the original Martin sound. I'm not saying this
can't be true, but if it is true, I would like to know the physics behind it.
Simply because a true spherical arch is more resistant to vibration. This is the primary reason that I don't prefer
the profiled arch around the perimeter of the top. The guitars I have played that have that construction are too
Author
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stiff and lacking in bass response. I think that the best vibration occurs when the edge of the top is in a single
plane. I do bevel the kerfing, particularly in the waist area of the tight-waisted shapes. But I have found that
with the small amount of arch that I use, very little beveling of the kerfing is necessary on dreadnoughts.
Another arching tip that I have mentioned before is the assymetrical top arching that I use. This is done to
counteract the torque that the bridge applies to the top. My braces have a 25 foot radius arch, except in the
area below the bridge (lower bout). In that area, my braces are perfectly flat. This results in a bridge that is
slightly "tipped back" when the guitar is unstrung. With tension, the torque on the bridge will rotate it, making
it level with the plane of the edge of the top. IMHO, this produces the best chance for vibration.
Quote:
on my monitor, the second pic shows an almost dead straight back taper (side view of the binding where it
borders the side wood). It seems no wonder the crosswise arch is strongest at the waist.
My first guitars were Gibson copies, using this construction technique. I found that the tight-waisted L-00
bodies tended to produce a 'pucker' in the waist area of the tops and backs. Since then, I have found that many
old Gibsons develop cracks in this area.
John
FoolForWood
#15
[-]
Great info, John (Willi, too!). It's bedtime now, but I'll be back. Still can't believe I missed this thread.
Quote:
all arched backs are 'pre-stressed' when they are glued to the body, since the cross bracing does nothing to
generate a longitudinal arch.
(01/25/07 6:27
PM)
When you posted I was editing my previous post. I added how a friend makes the lengthwise arch.
Henk
FoolForWood
#16
[-]
John,
I realized that round structures (2 and 3-dimensionally) are very strong and stiff. If you look at very old
architecture, people already knew this millennia ago. Chickens have a feel for it, too.
But purely thinking with the wrong half of the brain, and a bit with the gut (wrong, I know), I thought the H&D
(01/26/07 12:47 claim was strange. If one does it the way you do it, viz. starting with a 25 ft radius in the middle and then gently
PM)
smoothing to flat, it's easy to see that that is less stiff than a true 25 ft arch all the way. The flat portion will be
Author
Comment
less stiff and there will be less tension in the wood there. (Not necessarily the same thing, or is it?) However, if
you take that already stiff, perfect 25 ft radius and you have to force it to a flat shape at the perimeter, you'll
have to be introducing extra tension. This tension will be at the rim, where the existing curve is forced flat, but
even more at the transition from flat to curved, where the shape is actually deformed from convex to concave
for a short distance. In fact it will look like a very mild archtop guitar shape. But a good archtop's plate is carved
(no tension) instead of pressed.
H&D's modern style is spherical. Your style I would call semi-parabolic. And H&D's "traditional" style I would call
a-spherical. (Like an archtop, a hi-tec photographic lens or a smooth EQ curve.)
So the idea that I have to get used to, is that a spherical arch that is forced into an a-spherical arch, is less stiff
than the original spherical arch. Just to make sure I understand what you're saying,
You wrote:
Quote:
a true spherical arch is more resistant to vibration
Is that ALWAYS true, no matter the extra tension in similar shapes? Or is the following quote the key?
Quote:
It is MHO that this pre-stressing is a temporary effect that is minimized a short time after the guitar is strung.
So, after the stress differences are neutralized, what remains is the difference in shape, of which the spherical is
the stiffest.
Sorry to be such a drag, but I believe this is very important.
Henk
BHguitars
(01/26/07 2:21
PM)
#17
[-]
I look at the arches of top and back as a unit or part of a complete construction or concept. For me it does not
make always sense to isolate single attributes and conditions coming to one way directed conclusions. So it is
not valid in my opinion to conclude that an arch is more resistant against vibration than a flat surface. One
could also say that a flat surface does not have any tension and will sound worse for this reason. It is not valid in
general this way. So every attribute and condition concerning arches and sound quality have to be rated in their
direct context. Sometimes it is not possible to come to conclusions at all since the same arch or technique
works different for different makers. So a flat top at Santa Cruz may not be the same thing as a flat top at Taylor
or an arched top at Gibson is not the same what we do. But before any rating of old arching patterns and
techniques takes place the three main steel string flattop manufacturers and inventors should get a look at the
Author
Comment
conditions and circumstances under which they developed their constructions and designs. They differ at
several levels:
1. Martin was always rather conservative in their innovations, in their style of building but also very serious and
presize concerning craftsmanship down to the details. In 1930 Martin had about 100 years experience in flat
top guitar making - at parlor size and gut strings - but only about 4 years experience in construction of a bigger
steel string flat top.
2. Gibson ever did nothing else than steel string instruments but mainly archtops and mandolins. The modern
steelstring flattop construction at Gibson was in 1930 brand new. Gibson is well known for their pioneering
spirit and for their always progressive orientated style of management. Craftsmanship was great but not down
to details and as I would say: constructions designed for straight forward operations.
3. The Larsons are the actual inventors of the modern steel string flattop guitar. They are wellknown for their
multiple brilliant inventions. Lots of patents applied for in the early 20th century long ago before Gibson and
Martin thought about constructing a steel string guitar. In 1930 they had already about 30 years experience and
history in design and construction of the steel string flat top. As we know they didn't continue after the 40's and
most of their inventions and concepts were buried - till the recent time.
The Larsons created the modern concept of the pronounced arch for both - top and back. They always worked
with raised side profiles at the waist and their guitars had a markedly strong longitudinal arch. Their guitar and
creations are not only well known and highly appraised, they sound outstanding.
Now it would make sense to look at arches and various concepts in front of these backgrounds. So there is a lot
to be figured out why Gibson did not raise the side profile at the waist, what kind of arches Martin developed
and why the Larsons always "built under tension". So it would be a good idea to look into one of the Larson
books also to learn about this.
Today I've taken some more pics to show various arches and hope to post tomorrow with some details to be
discussed.
Willi
FoolForWood
#18
[-]
Willi,
I was going to study the moon phase post, and then I find this thread. So many great topics, so little time.
(01/26/07 3:47
PM)
Your historical sense of the evolution of the steel string "flattop" is right on the money IMO. The luthier friend I
wrote about, has the Larson book. I read it about ten years ago. I think I will borrow it again. The brothers are
really underestimated when compared to Martin and Gibson. But recently the prices of instruments they made,
seem to be going up rapidly. (Or so I've heard; I'm not into making money on guitars). John Greven has quite a
lot of succes with his Prairy State model. (Approx. super jumbo size with approx. OM depth). You have the
Milwaukee series with four Larson models. How have they been doing compared to the Martin and Gibson
inspired models?
Author
Comment
Quote:
Today I've taken some more pics to show various arches and hope to post tomorrow with some details to be
discussed.
Since it is winter now, you are bound to be busy with making guitar bodies. Could you post a couple of pics,
showing the way you prepare the sides to accept the plates? Please.
Thanks.
Henk
#19
[-]
Quote:
Steve Frost
While those pre '35 had a less arch the typical Gibson arch started with the beginning of the codeletters
meaning in 1935. But the pre' 35 Gibsons already had an arch although this did not include the important place
around the sound hole and above the bridge.
Does this mean that starting in '35 the braces above the bridge were arched? And did Martin approach this
area, the transverse brace and upper part of the X, in a similar way?
(01/27/07 2:09
PM)
FoolForWood
I ask because I'm at a crossroads in my building. I've made seven guitars with flat tops (unarched top braces).
I'm just finishing the binding on #8, which has back and top radiused with 15' and 25' dishes. #9 is my nod to
the Advanced Jumbo. The top is partially braced right now, using a 25' radius and the brace placement and
measurements Wlli supplied. I'm about to get back to it, but want to make sure the transverse brace is also
arched before I glue it on. I know that some builders use a flat cross brace here for various reasons.
Of course, I'm not committed to using one method for all guitars, either. I'd just prefer to keep it consistent
within each individual instrument. You can get burned from mixing- and- matching. Ask me how I know!
#20
[-]
Steve,
Flat=hollow.
This may seem a strange statement, but if you've built seven guitars this way, I think you know what I mean.
(01/27/07 3:02
PM)
ALWAYS build with a subtle arch. Not only will it give the top the necessary strength, also it will allow for some
movement when humidity gets low. When flat, it will either get hollow or it will crack. If you don't build under
Author
Comment
climate controlled circumstances or during the dry season, problems WILL arise. The traditionally used water
containing glues won't help in this respect, either.
If you use the 25 ft radius dish method, then the upper transverse brace is automatically arched, as well. If you
don't use the dish, but do arch the X-braces, keep in mind that the back angle of the neck should be more
pronounced now, as the bridge sits on a hill. You could use a flat upper transverse brace in this case, but then
you'd have to wedge/bevel the upper bout's side plane, let's say 1 1/2 degrees, from the soundhole area to the
heel. Another option is radiusing the upper TB, too. If you fear the slight roundness of the top when you glue on
the fretboard, this can easily be sanded out to a straight taper; it's not much.
The Chinese GAD Guilds have a nicely executed 25 ft radius top (lower bout). Also, the good ones have a mild
back set of the neck. But the upper transverse brace is dead straight. This means that on the "good" ones (wit
proper back set necks), the fretboard extensions fit is a bit weird.
Even if you leave all top braces flat, you'd still want a very slight back set of the neck IMO. Firstly, string tension
will always make the guitar fold in a little. Secondly, the fretboard thickness plus fret height is less than the
bridge height. If you do the Frank Ford test, the straight edge will end up below the bridge's top.
I have a plan here of a Martin 1-18, drawn by Ted Davis. I believe John Arnold knows him from the red spruce
hunts. The top braces are basically flat, and the fretboard is only 3/16" thick (vs. 1/4" nowadays). The bridge is
thin, but taller than fretboard and frets together. Yet, there is zero back set of the neck. Beats me. But, as I said,
I'm no luthier, so what do I know.
Edit: I gave the Ted Davis plan a second thought. The plan was made from a 1918 instrument, so it probably
wasn't easy to determine the original geometry. Also, it was originally designed for gut strings. Maybe these
needed a considerably higher action.
Henk
#21
[-]
Quote:
BHguitars
(01/27/07 3:22
PM)
Since it is winter now, you are bound to be busy with making guitar bodies. Could you post a couple of pics,
showing the way you prepare the sides to accept the plates?
Right, it's snowing since some days and the air is cold and very dry. Excellent for bracing tops and backs and
building the entire body. We already started with the bodies (12) and I'm working on 21 necks. The rims will get
the tops and backs till March I guess. I'll tyr to shoot and post some pics as far as I find some time. BTW Henk,
how do you know we are only building during the winter? Did I mention before?
Quote:
Side profiles would be great to see Willi. I'd be especially interested in a OO-14 fret side profile.
Author
Comment
Our side profiles are contured to match the arches we work with, so they are more pronounced than Martin's
side templates. But I will see if a can post some profiles.
Willi
#22
[-]
Quote:
Does this mean that starting in '35 the braces above the bridge were arched?
BHguitars
Yes, the entire top shows a pronounced arch including the areas above and below the sound hole. That's the
important place besides the bridge: below the sound hole just where the X is placed and above the sound hole
under the fret board extension.
Quote:
And did Martin approach this area, the transverse brace and upper part of the X, in a similar way?
(01/27/07 3:44
PM)
No, not this way to my knowledge. While Martins have some arch especially at the winter build guitars the
sound hole area mostly is sunken in what means no arch between sound hole and bridge were the x is placed
and above at the finger board extension brace. But more about this later.
The AJ we talked about at the AJ thread does not have such a pronounced arch at the X center as far as I can
remember. But this was not intended, the top looked sunken in a little at this place as far as I can remember.
This would be a question for Christian to look again at his guitar and shoot a pic from the side to show the top
arch.
Here are some pics of Gibson top arches using my famous arch measure instrument. First the 1939 Recording
King Ray Whitley that is similar to the AJ except for its short scale and non scalloped bracing. It shows the
typical nice top arch at the bridge viewed from the end pin:
Author
Comment
Large image
The same arch as my 1942 SJ shows:
Large image
Here is visible that the bridge shows absolutely no twisting or bellying. The top arch looks the same up and
down the bridge and soundhole. Gibson arch at its best. Visible also that the sound hole area is raised above
the side level meaning there's the same arch at the X-center and at the finger board's end:
Author
Comment
Large image
Martin top and back arches later.
Willi
FoolForWood
#23
[-]
#24
[-]
Quote:
BTW Henk, how do you know we are only building during the winter?
(01/27/07 5:16
PM)
Willi,
Big Brother is watching you.
Henk
Steve Frost
Quote:
flat =hollow
(01/27/07 5:28
PM)
Henk- I have heard that said, but I'm really not seeing it borne out in my guitars. My first guitar, a 12 string, was
finished in 1980, and has been strung up to standard pitch ever since. My buddy brought it over a couple weeks
Author
Comment
ago, and the top looks fine. It's braced according to D.R.Youngs plan, tapered braces, not especially overbuilt. I
built the first 6 in the early '80's, and they're all holding up well, no cracks, splits or hollows. So I'm not saying
that this is the best method or anything, but I took Irving Sloane's word for it, and it's worked out pretty well.
Internet forums were scarce in 1980, so I worked with what I had available at the time- a couple of books. It
doesn't mean that I'll reject a better method now!
FoolForWood
#25
[-]
Steve,
First, congratulations! You may have started the most significant thread on the UMGF, yet.
About the flat tops. Where do you live? And during which season did you build most of your instruments?
(01/27/07 5:48
PM)
Henk
#26
[-]
Willi,
Great pictures, man. The first two could get mistaken for a bellying problem. But if you look well, the curve is
too smooth for that. (No "creases"). The last one makes it very obvious; beautiful arch all the way to the
fretboard.
The big question is often:"Where do I want the apex, or top of the hill." Some feel the spot where the X-braces
cross should be the apex. Others want the bridge on the top of the hill. And then there are those who want it
FoolForWood
halfway between the bridge and soundhole (this CAN be the place where the X crosses, but that ain't
necessarily so) or halfway between the X and the bridge.
(01/27/07 7:33
PM)
Most classical builders and some steelstring builders don't use the modern spherical dish, but do use a
workboard called a solera. It is shaped as the 3-dimensional photo-negative of the guitar's top. These can be
quite complex with hollow and flat area's. Classical builder Greg(-ory) Byers uses one that gives his tops a 3 mm
rise halfway between the bridge and the soundhole. (Classical, remember, so 12 frets ttb, backward bridge and
no X). The area behind the bridge he leaves essentially flat. So the apex on the UNSTRUNG instrument is
between soundhole and bridge. But when the guitar is strung, the bridge area rises and a fairly smooth arch
develops, with the actual apex right at the bridge's position, where he believes it should be. This, IMO, is quite
similar to what John Arnold described earlier in this thread as the method he uses for his steelstring guitars:
Quote:
This results in a bridge that is slightly "tipped back" when the guitar is unstrung. With tension, the torque on the
bridge will rotate it, making it level with the plane of the edge of the top. IMHO, this produces the best chance
for vibration.
Author
Comment
Henk
Steve Frost
(01/27/07 7:47
PM)
#27
[-]
I may have gotten by on a firm foundation of dumb luck! There's no pattern to where or when I've built. When I
started building, I worked wherever and whenever I could, variously in Massachusetts, New York and Virginia,
in basements, bedrooms and garages, in whatever season. So, nothing there to explain a lack of climate
induced disasters. During that same period of time, I also built 3 F5 mandolins, an A model, and an H5 mandola.
Then I got sidetracked by marriage, a teaching career, and kids. I've lived in Maine for the last 20 years, and
now have a basement shop with a dehumidifier, as needed.
The posts in this thread are doubtless going to change the way I think about bracing a guitar. They already
have! I've been working off incomplete information since I first found Young's Steel String Guitar book in 1977.
BTW, I love that book- I don't follow it closely anymore, but it did portray the process of building a guitar as the
totally absorbing kick that it is!
#28
[-]
Quote:
I may have gotten by on a firm foundation of dumb luck!
Not very likely. I'll provide some more guesses.
FoolForWood
1. You used well seasoned woods. And maybe WR cedar or even redwood sometimes? Those hardly shrink at
all.
2. You knew right from the start not to use the whole glue pot in one go.
3. Your customers don't live in Arizona.
(01/28/07 7:47
AM)
The above would help against shrinkage.
4. From what I understand, you used tapered, non scalloped bracing. Such systems are very stiff near the centre
(X), and would give good resistance against sinking in in front of the bridge.
5. You have a feel for wood. Have you thought about that one?
Next questions. When at work, like in a garage, did you have your coat on, or did you make sure you were nice
and comfortable without one?
Did you give the necks (not talking about the archtop mandolins) a slight back angle? If so, did (do) the FB
Author
Comment
extensions dip on the body, or did you plane the FB after joining the neck? Or did you wedge the extensions?
And how tall were (are) the bridges? Finally, what is the average action (12th fret) like, today?
Willi,
I was just teasin' ya, of course. Here are your own words, from that other fantastic thread; the one on which we
first met (on the forum, that is). It is now on page eight of this section. We'd better save it before it goes
beyond page twenty!
Quote:
The drier the top the more arch (and strenght) you get (for this reason we only build bodies during the dry
winter season and never in summer).
Back to the pictures. The first pic shows the Whitley, the second your Halibut. The third (long view) doesn't say,
but from the belly down bridge, I'd say it's yours. (Why on earth didn't I buy it in Veenendaal?). Is the '39
Whitley's top as smooth as the top on yours, lengthwise? And don't you think it's odd that the back of the
Whitley is not nearly as well executed? Is that the ever varying Gibson thing? Or is the '42 so good, because
only the best builders were present at that time?
Henk
Steve Frost
#29
[-]
One thing I find so intriguing about this discussion is that some of it is news to me. As I said earlier, I've
frequented builders forums for quite a while, and I have never heard anyone bring up the fact that the vintage
guitars weren't built with the (now seemingly ubiquitous)
spherical arch method. Thanks for cluing me in!
(01/28/07 11:51
AM)
Steve Frost
#30
[-]
Henk , the action on my guitar is about 8/64. Problem is, I'm running out of saddle, and it could probably use a
neck reset, after 25 years. I find that prospect unappealing, so I'll live with it for now. I'd rather spend the time
working on something new.
(01/28/07 12:08
PM)
Pretty good guesses in general, though my tops have all been Sitka or Adirondack, so far.
Author
John Platko
Comment
#31
[-]
Willi, would you outline your build process for us and explain how you go about getting the arches that you are
after?
(01/28/07 12:57
PM)
Thanks.
FoolForWood
(01/28/07 1:12
PM)
#32
[-]
Steve,
Although it is not a luthier's forum, this is the place to be. Trust me. I don't say this because I post here. I've
known most of the specialized forums for years. You're in the best possible hands here, with John and Willi on
board, not to mention the others. It is why I really believe this club deserves a luthier's corner. I suggested this
last month. It didn't work. No harm done; we'll manage without it. The person who would make this place
totally complete IMHO, would be Alan Carruth. He knows so much, and is such a kind guy. If he got on board to
join the great masters we already have, you could close all lutherie and most acoustic guitar forums. (Mmm, OK
let's save the MIMF )
Henk
#33
[-]
Quote:
BHguitars
Willi, would you outline your build process for us and explain how you go about getting the arches that you are
after?
John,
I'll take some pics and will see how they turn out for a documentation purpose. BTW, very simple what we do
but possibly interesting for people who want to get an insight in workshop guitar building operations.
Quote:
(01/28/07 2:14
PM)
Is the '39 Whitley's top as smooth as the top on yours, lengthwise? And don't you think it's odd that the back of
the Whitley is not nearly as well executed? Is that the ever varying Gibson thing? Or is the '42 so good, because
only the best builders were present at that time?
Henk,
The RKRW's top arch is even better than my SJ's - it has the original bridge that never was off and a nice bridge
Author
Comment
saddle height by excellent action - now neckreset done. My SJ has a nice arch but was in need of a neck reset as
I got it from Las Vegas and also had the center seam open. As it came there was already no arch left. It took
about 4 week but the arch came back fortunately.
Most of the Gibson tops I have seen have a nice arch. Especially J-35s I remember that were not in need even of
any set up work, so fine was their structural condition with original neck sets and bridge glue joints. This mostly
is the reason of fine top arches and a solid upper bout construction mainly. Those tops that are not perfect
mostly have some issues like pick guard shrinking and loose braces underneath or any other loose braces over a
longer time space. But mostly they are nice.
Many of the rosewood B&S round shoulder Gibson backs have such a strong arch, more than the mahoganies. I
remember a '42 SJ and a '36 Smeck with a similar arch at their RW backs. But possibly this was only by chance.
Probably the backs were dried down too much before they were glued on. This would answering also why those
backs often have bumps. The slab grain parts of the wood build up stronger bumps when the load some
moisture after bracing and glueing onto the rims.
Willi
#34
[-]
Quote:
And did Martin approach this area, the transverse brace and upper part of the X, in a similar way?
Quote:
BHguitars
(01/29/07 4:14
AM)
The big question is often:"Where do I want the apex, or top of the hill."
While Gibsons after '34 have a clearly noticable top arch above the bridge and around the sound hole up to the
upper body edge, Martins don't have such an arch in a similar way. The Martin arch depends on other factors.
But first some different arches found at '30s Martins. In most cases a slight belly (more or less) will be found
presuming that no bad bridge repair (with cut through spruce grain at the bridge glue joint or bridge plate
work) has taken place before. While the area below the bridge can show an amount of upper belly, the area
above the bridge mostly looks concave more or less (most important for the healthy top condition is that there
is no kink at the bridge edges). So when the bridge (wings) viewed from the side aligns with the top surface in a
smooth curve everything is well. But while most people look at the area below the bridge I look at the bridge
(wings) and at the area of the X-center between bridge and sound hole and also the area around the sound hole
to check out how much the top and the X-center have been pressed down and are sunken in. At least I would
want for a new guitar:
1. the bridge being above the rim level
2. the X-center and sound hole area above the rim level
This means more or less I don't like any sunken in places at a guitar's top.
Now for my understanding of the prewar Martin top construction the Martin top arch (if there is one actually) is
gained through low moisture content during the bracing operation and when the top is glued onto the rims
Author
Comment
(possibly a slight curving of the braces but this is not determining). As I figured out before the tops (and other
parts) are stored up the room were the dry and heated air is passing by. This way the woods are stored over a
longer time space (we do this minimum one year) before they will be used. When it comes close to the bracing
the tops (and backs) will be stored closer to the room heater. Right before the bracing operation the tops will
heated a little by an air heater or placed upright against the room heater. This is requested if hide glue is used.
This technique is old and is common in Germany since a long time. Also the Spanish guitar makers work this
way. I'm convinced that Martin (and Gibson) tops were treated the same way. Otherwise one will get into
trouble especially if hide glue is used. This pic and description is featured at the Washburn & Johnston book at
the post war chapter:
The description says: "Note the drying racks for wood, suspended from the ceiling ..." Further on a Martin
craftsman recalls: "We'd actually stand the wood on the radiator and heat it before putting the glue on because
with hot animal glue, if you put that on while the wood is cold, it won't stick as well".
While this description mainly is referring to the usage of hide glue, the heating of wood as preparing operation
step comes quite clear. Also: why should Martin change this techniques since it is obligatory for the traditional
guitar making since ever.
The top heating technique comes obvious also as we look at those parts of the top, where the braces have been
scalloped. Especially those places of the braced top will show an arch that have been weakened from the inside
through the scalloping. If the top has been braced once and the brace is scalloped one can see very well how
the top arches comes out very quickly at this operation step. We used this technique for over a couple of years
Author
Comment
and for about 200 guitars before we switched over to the stronger arch we do now since 12 years or so.
Here are the guitars.
First is a D-28 that was built in late summer 1937. It shows nearly no top arch. The top is very flat:
Large image
The side view shows that the top is sunken or pressed down above the bridge and around the sound hole:
Larger image
It is obvious that the wood grain cotained more moisture during the bracing operation. While in winter and
spring it is easy to get the wood dry enough. In summer and fall this is a big problem and is even not easy to
Author
Comment
handle at all even at modern facilities.
The same year of manufacturing is this D-18, but it was built in early 1937. The winter and spring seasons are
the driest and best for building the bodies since the woods have the lowest moisture content. This top arch is
even stronger than an average Gibson arch:
Large image
The side view shows that the bridge level is clearely above the rim level but the arch is running off towards the
sound hole:
Large image
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Comment
Comparing the sound character of bouth guitars one could notice at once that the D-18 has much more power
and volume from the bass up to the trebles. BTW, the D-28 is excellent sounding but this D-18 is the best
sounding and the one with the strongest top arch I've ever seen.
Here's another guitar that shows the best arches I have seen at a '30s Martin. It's an early 1936 00-21 with
perfect top and back arch. While the lower bout and the bridge area is arched well the X-center and soundhole
area is not sunken in although strung up with mediums since many years. There's no crack or any other
structural issue at this guitar:
Large image
The side view shows that there is nearly no twisting of the bridge:
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Comment
Large image
For my understanding it doesn't matter too much what way a top arch is constructed. But for me there's no
doubt and also according to my experience at new guitar construction that a top arch is a very important
construction feature and improves the sound quality clearly. The technique of drying down and heating a top
before bracing effects a much higher top tension that I appreciate really. Also for my understanding those
guitars sound much better and are much more resistant against neck angle and bridge belly problems and top
cracks.
Willi
FoolForWood
#35
[-]
Is there anyone here who could provide a link to a lutherie forum, or a vintage forum, or any forum, where
information like this can be found? And explained and illustrated in a similar manner?
Willi already lifted a tip of the veil in an earlier thread. He seems to be going all the way now. What will this info
mean to vintage collectors? What will happen to the prices of guitars with serial numbers early in the respective
years?
Oh, and to those who are building the Martin D-18 and D-28 Authentic. What do YOU think of all this? Come
out of the shade. This is a Martin forum. We won't bite ya.
(01/29/07 5:58
AM)
Henk
Author
Comment
#36
[-]
Quote:
What will this info mean to vintage collectors?
BHguitars
(01/30/07 3:59
AM)
Henk, I guess this won't have any meaning even if people would start to do their own research. What I tried to
figure out only is a tendency that shows up as possible answer at the question what humidity, moisture
contend in wood and seasonal conditions can effect on top and back arches and also some thoughts about
humidity and guitar construction at all. I meant "can effect" and in my oppinion it does but there's no must or
any straight rule. I guess there are other Martins that won't show these differences that much. But it may be a
very important aspect to research guitar making prior to the war and of corse for us today how to organize and
to conceive the place where and how we want to build guitars. Many of us started in any way in the kitchen,
cellar, garage or wheresoever. A modern facility means mostly a modern building industry like with humidity
controll. But still there are big problems even in humidity controlled buildings. It's not as simple as it sounds
and as straight as the hygrometers and the air-condition machines want us to believe. The conditions of the air
where one of the main reasons for us to move our workshop to the place we we currently work at. We have
two main rooms, the dryer workshop (more heated) where we also store most of the wood and the less heated
room for everything else where we store also the completed guitars. The building is from the 16th century and
has nature stone walls about 40" thick. This means minor changes concerning air conditions since the thick
walls save the air temperature and humidity very well and keep them at an uniform level. This is what we
believe is very important for guitar making that the humidity won't go up and down inbetween a special time
space while the guitars are made. So when we build the bodies the woods and the air conditions are dry
enough (not too dry) until the bodies are done. So there won't be any unintended ups and downs concerning
the air conditions, the content of moisture inside the woods and tension at the arches. There are some pics of
our workshop shown at the Blue-G page that show the thick building walls.
Quote:
the Martin D-18 and D-28 Authentic
There always has been a difference between authenticity and Authentic. Authenticity includes mostly the long
research of the art or manner of guitar making practised prior to the war. Authenticity includes seriousness and
convinceness and most of all a consciousness. I believe that there's no magic in how the old guitars were made
- but since the way of guitar making after the war always was determined by commercial interests and always
was under the command to build more guitars in a cheaper manner (nobody was asking for better guitars), so
many of the old skills are nearly lost but still visible underneath the surface. So we have to undig and to recover.
But I guess it takes a little more than the Martin guitars feature. That's what many of the small idependant
makers try since the recent decades. This is an endeavor that can last easily a hole professional life and career.
Now since a short time Martin has realized that there must be some truth in this while learning from these
people ... I hope they are serious enough and don't add only one more page to their catalog.
Willi
Author
John Platko
Comment
#37
[-]
#38
[-]
Thanks for the photos and descriptions, Willi.
(01/30/07 10:46
AM)
Quote:
Henk, I guess this won't have any meaning even if people would start to do their own research.
Willi, you underestimate yourself. And who will do that research (apart from some small shops, maybe)? Not
the vintage dealers, most likely. They tend to be more interested in which models from which years can make
them the most money. Often, the ones I spoke with couldn't even answer the simplest questions about the
FoolForWood instruments themselves. (There are exceptions of course; Eric Schoenberg comes to mind. But he's a musician
first, like you are a luthier and repairman first). But they usually ARE very good at pointing out the usual goodies
that are the reason for the extra dollars on the price tag. (Most of those not nearly as important as the subject
we're talking about in this thread).
And the manufacturers. Well, they seem to be having other things on their minds, too, as you have pointed out.
Some serious arts and crafts philosophy there BTW, especially your last paragraph. I hope Chris Martin reads it.
(01/30/07 12:18 He's done some good things for the company, but I believe he could do much better still. Somehow I feel
they're at an important juncture at this moment. Maybe what we'll see is a split between the mass production
PM)
of Felix "guitars", MTV models etc etc etc on the one hand, and a back to their roots, good old Martin "not too
small" shop where they can expand the Authentic formula. I do hope the marketing experts throw all their
energy in the first branch, and stay FAR away from the second. Hey, perhaps Chris could make a "back to his
roots" trip to Germany and Austria, and take his best luthiers with him. That should bring them in the right
mood. Not only sightseeing, mind, but some study of the old craft, too. His ancestors, plus the very
important employees of days gone by, like Mr. Deichmann, would surely like that, or I would think. They could
cherrypick some great wood, too.
Now, what we need for this thread is another authority (my vote goes to Jonn Arnold) who can underline the
pattern you have found. John, you have seen and studied many prewar Martins, both winter and summer built.
What do you say?
Henk
Author
Comment
P.S. I'll be back for more on the workshop.
#39
[-]
Steve Frost wrote:
Quote:
I may have gotten by on a firm foundation of dumb luck!
I found the David Russell Young book to be a combination of the most useful and the ridiculous. The most
useful passages had to do with building the arch into the top and back, and the careful control of humidity
during assembly. IMHO, the ridiculous parts had to do with butt-gluing the neck to the body with epoxy.
Quote:
Arnoldgtr
John, you have seen and studied many prewar Martins, both winter and summer built. What do you say?
(01/30/07 3:33
PM)
I haven't correlated the build time with the shape of the arches on prewar Martins, but I am a firm believer in
winter assembly. As I first read in David Russell Young's book in 1976, the most important factor in guitar
building is control of moisture in the wood. For stability of structure, the best guitars are assembled when the
wood is as dry as it will ever be in the guitar's life.
The first thing I look for in a new guitar is the shape of the top arch. If the top is dead flat or sunken between
the soundhole and the bridge, it is a recipe for trouble. Unfortunately, I see too many new Martins with this
condition, and I believe I know why.
Martin has used arched top braces for years, although they have been clamped to the top against a flat surface.
In older days, the braces were clamped to the top at full height, then shaped after they were glued on. This
meant that the braces were stiff enough to spring back a little, producing some arch in the top. But today,
Martin's braces are all CNC carved before they are glued to the top. This weakens them considerably, especially
the ones that are scalloped. Without the stiffness in the braces, the top remains flatter once the gluing is
completed.
As Martin used to do, I glue the braces on the top at full height and carve them afterwards. The difference is
that I use curved cauls against the top when gluing the braces, forcing the top into the shape I want. This is a lot
more consistent than hoping that the braces will spring back to their original shape.
I believe that producing a consistent arching is the key to producing a consistent sounding guitar.
Like Willi, I am fortunate to have a very moisture-stable workplace to build guitars. I keep records of every piece
of wood that I use. I know all the particulars as to when it was obtained and resawn. I also keep notes about the
stability characteristics of particular BR logs I have cut.
I make great use of a moisture meter, particularly during the seasoning process. The more you know about the
Author
Comment
wood's behavior, the better chance you have of success.
John
#40
[-]
Thanks John,
Quote:
Martin's braces are all CNC carved before they are glued to the top. This weakens them considerably, especially
the ones that are scalloped. Without the stiffness in the braces, the top remains flatter once the gluing is
completed.
You mention an important point here. I have a couple of Martin catalogues here, and in the Vintage Series
section there's a woman with a chisel in her hands, standing over a scalloped soundboard. The tip of the chisel
touches the end of a brace. Of course WE know, if at all, she is adjusting the end's height to fit the lining. In the
1997 version, the text in the picture says "scalloped" bracing. This is not a lie per se, but misleading to say the
FoolForWood least. In the 2000 version (younger woman now), the text in the picture says "scallopING braces". With a whole
lot of fantasy you could say they mean scalloping the very ends only, but to me it comes very close to "I did not
have sex with that woman". The Martin name is too big for this kind of practice IMHO. But although I don't like
the idea of pre-scalloping at all, from an economic point of view I can understand why they let the machine do
the job.
(01/30/07 4:49
PM)
What totally beats me, however, is why they would want to glue arched braces with a flat surface as support. It
wouldn't be a more expensive procedure to use an arched support, be it spherical or otherwise. Some use a
dish, others a series of arched pieces of wood, like in the go bar picture in Willi's workshop, that he posted
today. Could it have something to do with the vacuum gluing set up? I don't see a problem there either, but
maybe someone has an explanation.
BTW, my Vintage Series OM clearly has machined braces, but the ones on my OM-18GE (adi braces) look a lot
less perfect. The scallops may have been there already, but the beveling along them seems to be handwork.
You own one too, don't you? How are they done on yours? And speaking of that guitar, how is the rebuilding
project coming along?
Henk
Author
Comment
#41
[-]
Quote:
Steve Frost
What totally beats me, however, is why they would want to glue arched braces with a flat surface as support.
(01/30/07 6:44
PM)
John Platko
C'mon, Henk - aren't you paying attention? If they didn't do it that way it wouldn't be traditional! Of course, I
agree- that doesn't make a lot of sense, and really never did, even when full depth braces had a realistic hope
of springing back.
Re: David Russell Young's book- I've got to say, that I never subscribed to his epoxied neck butt joint. And I
didn't try the arched top bracing at that time. I did use some of the additional bracing recommended around
the brace under the end of the fingerboard. I think he made a huge contribution, even if I don't endorse all of
his ideas.
#42
[-]
John, could you talk a little bit more about how you arch your guitars. Does the arch continue above the
soundhole? Are you going for a sphere or something elese on the back?
(01/30/07 8:05
PM)
#43
[-]
Quote:
BHguitars
But although I don't like the idea of pre-scalloping at all, from an economic point of view I can understand why
they let the machine do the job.
Quote:
(01/31/07 4:47
AM)
But today, Martin's braces are all CNC carved before they are glued to the top.
Martin today is a modern manufacturer and their products are designed for high output machine made
operation steps. That's what I meant in saying nobody was asking for better guitars - the question always was
and still is how to make them fast, cheaper and more of them. I still wonder how they will use hide glue for the
Authentics in an industry hall? Possibly the same thing as with their "nitro lacquer" that is almost a PU finish. As
long as no they don't hire old fashioned crafts man and open a small workshop all the new Martins are industry
Author
Comment
mass products and not seriously hand made guitars.
Quote:
As Martin used to do, I glue the braces on the top at full height and carve them afterwards. The difference is
that I use curved cauls
That's how it works the best for us as well, also the full height braces glued before shaved as shown here. Our
preference: to glue all braces (for top and back) in one operation step, this guarantees no changes and stress
during the bracing.
The mold we use for the backs show mainly the transverse arch, only minor arched longitudinal. The
longitudinal arch is added when the back is glued onto the rims through the side profile. We have a similar mold
for the top bracing operation but this is molded exactly exactly how the top arch should look in the end. The
braces are fitted exactly to the mold's curve before they are glued - no machine routing. Every brace is fitted
exactly to the place it will be glued onto.
I like to pick up some of John's ideas and descriptions concerning back arches posted in the beginning. But first I
want to post some pics of different back arches. Very interesting to compare Gibson to Martin but also
different Martin models and years of production. I want to add that these results depend on the guitars I have
on hand or what I have seen before. So other guitars may look different. But fine anyway to come to some
Author
Comment
conclusions.
First the 1942 SJ. As shown before, Gibson has a low waist at the side profile (not raised to match the narrower
back dimension at this place). This leads to a stronger arch at the waist. Besides this the transverse arch is less
than Martin in general (except those rosewood Gibson backs I mentioned before). The longitudinal arch is less
even more. So the tops are almost arched the same as the backs.
Large image
Large image
For Martin back arches I want to start with some early steel string guitar arches that show a very weak arch.
Here's a 1926 000-18 that shows almost no longitudinal arch and a minor transverse arch:
Author
Comment
Large image
Large image
Very similar weak arch to be found at this 1927 0-21. Some arch tranverse that is stronger at the waist and less
at the lower bout but a very minor longitudinal arch:
Author
Comment
Large image
Large image
Now compared to this unique 1934 0-17:
Author
Comment
Large image
Large image
The back arch is incredible in all directions. While a 1931 000-18 is arched the same as the minor arched 1926
000-18 and other 12 fret pre'30s Matines I have seen in early 1930's the arch seems to have changed. At this
guitar they have "over-arched" possibly but I can imagine what idea they had possibly.
Now here are typical Martin back arches that can be found at '30s and later Martin usually the way John
described before with a transverse arch that is stronger than the longitudinal in general. The arch at the waist is
stronger and the lower bout long and wide back braces show mostly a weaker arch looked at the average
transverse arch. This confirms that the side profils show a raised waist, much stronger than to be found at
Gibson but still less than Larsons show. This means the short waist back braces are arched more to match the
lenght curve and the side level at the waist. For this reason the waist braces is more solid (same height or
higher than the upper bout brace and tall and narrow). Both lower bout braces are wide and flat to allow more
bass power. They hold the arch as well because of their arch and their bigger glue joint (note: the bigger glue
surface keeps arches firm also but not as solid as the tall and narrow braces):
Author
Comment
A 1941 000-21 with typical arch and a somewhat sunken in area at the longitudinal arch at the first wide back
brace that could be seen often:
Large image
Large image
The 1937 D-18 shows a similar arch with slightly sunken in longitudinal arch at the lower bout. The waist arch
looks stronger but also the waist looks to be raised more. So here we have a side profile that matches more the
back arch at the waist - the raised waist design:
Author
Comment
Large image
Large image
Same shows this 1937 0-21. The flat braces at the lower bout are sunken in a little but the narrow waist is
raised noticeable to match the transverse and the longitudinal arch:
Author
Comment
Large image
Large image
Now this one again is the best one, the 1936 00-21 with an arch that looks similar to the other '30s arches
(except 1934 0-17) but with a very nice longitudinal arch that is somewhat less but not much different to the
transverse arch. The waist is raised and the narrow brace at the waist is arched nearly the same as the wide
braces at the lower bout. The arch viewed from all sides looks very smooth and uniform pronounced curved
with no bump or sunken in places. Also none of the back braces ever were in need to be reglued:
Author
Comment
Large image
Large image
Enough for today - to be discussed later.
Willi
Author
Comment
#44
[-]
FoolForWood
Hey Willi,
Do you just open a drawer with golden era Martins, when you want to show us some pictures?
(01/31/07 7:24
AM)
The back arches on Martin's archtop attempts in the thirties do have a very considerable arch. (At least the C-3
does). Strangely, they only carved the top, not the back. Some of the archtops were modified into flattops in
the seventies, but that's a different story, as you know.
Henk
#45
[-]
Willi,
About the workshop. Nice pictures on the Blue-G page. Why aren't they on the B&H website?
Those are some serious walls. I can imagine they provide a very constant temperature and humidity. A fairly
new trend in burglary is driving a stolen car through the shopfront, and then steal the goodies. Have they ever
tried that on your shopfront?
What I REALLY like is your traditional approach. While the whole world is shouting "faster", "more", "larger
scale", "merger", "automation", "CNC", "modern materials", "go with the flow or submerge", you stick with the
FoolForWood
old craft and prove you can still make a living. I think that's a big achievement. Of course you do repairs too, but
these are also performed in a traditional way. You do use a computer and a digital camera to share your
expertise, but we'll forgive you for that.
This is from the Bläzer & Henkes website:
Quote:
(01/31/07 1:13
PM)
Wilhelm Henkes, der einige Jahre zuvor mit dem Bau von Saiteninstrumenten begann und danach die
Meisterprüfung als Gitarrenbauer ablegte
Do you still have to be a master luthier in Germany, to be able to build and SELL your guitars? It was sort of like
this when C. F. Martin I fled the country (cabinet makers that were not allowed to do what the luthiers' guild
did). Of course CFM did have his roots, and did learn the craft, in Germany and Austria, but as a guitar builder
he was not very popular with the guild. (Others, please forgive for this short hijack).
Henk
Author
Comment
#46
[-]
Metropro
Just curious, what are the dimensions of the top braces on vintage Martins and how do they compare to
modern braces, both standard and vintage replicas? Since the vintage braces were hand sculpted, I'm sure
there is considerable variation.
(01/31/07 2:03
PM)
The consensus opinion seems to be that the non-tapered, non scalloped braces, produced poorer sound
quality. Yet, the D-35 with its 1/4" braces are also not tapered but deliver a richer tone. Are these D-35 braces
both thinner and not as high as traditional braces?
Chris
#47
[-]
Quote:
what are the dimensions of the top braces on vintage Martins and how do they compare to modern braces,
both standard and vintage replicas?
Arnoldgtr
Prewar dreadnought X-braces are 5/16" by 5/8" tall, nominally. The scallops and peaks vary, but the overall
dimensions are very consistent. For the most part, these are the same dimensions that Martin uses today.
Quote:
the D-35 with its 1/4" braces are also not tapered but deliver a richer tone. Are these D-35 braces both thinner
and not as high as traditional braces?
(01/31/07 3:04
PM)
Yes. The D-35 braces (which are 00 size braces) are 1/4" wide by 9/16" high, nominally. The stiffness is the key.
Although the width affects stiffness proportionally, the height is a different matter. Stiffness varies with the
cube of the height, so changing the height from 5/8" to 9/16" reduces the overall stiffness by 27%. The change
in width reduces stiffness by 20%. Total change in stiffness is about 33%.
This stiffness/height relationship is why scalloping the braces can change the sound of the guitar so
dramatically.
John
Author
Comment
#48
[-]
Quote:
Fingerstyle2
Wilhelm Henkes, der einige Jahre zuvor mit dem Bau von Saiteninstrumenten begann und danach die
Meisterprüfung als Gitarrenbauer ablegte
(01/31/07 3:07
PM)
Courtesy of Google's online translator, we non-German speakers now know that this means "Wilhelm Henkes,
some years before with the building of stringed instruments and afterwards the mastership examination as a
guitar farmer began put down."
I was OK until I got to "guitar farmer"....
David
BHguitars
#49
[-]
David,
Did you never try to take some genuine guitar crops and pull them into good southern soil, take care for some
water and fresh cattle dung twice a month (otherwise it will become a gut string guitar) and wait for some
young guitar leaves?
It works but you have to be really patient ...
.
This way you'll have much more time to hang around at guitar forums
(01/31/07 3:27
PM)
Willi
#50
[-]
FoolForWood
David,
(01/31/07 3:37
PM)
OK, maybe I should have translated it. I'm not German either, but both Dutch and English have the same
Germanic roots. So I thought "Meister" would be obvious, especially with the English question I asked after the
quote.
Anyway, that "guitar farmer" is brilliant. No wonder Willi is so fond of hide glue and tradition.
Author
Comment
Henk
#51
[-]
Quote:
Do you still have to be a master luthier in Germany, to be able to build and SELL your guitars? It was sort of like
this when C. F. Martin I fled the country (cabinet makers that were not allowed to do what the luthiers' guild
did)
BHguitars
(02/01/07 3:34
AM)
Although laws have changed recently in Germany concerning the master graduation (because of conflicting
European Union laws) requested for trades and craftsman's establishments the situation did not change a lot
since CF senior left the country in 1833. To run your own workshop or work as foreman one has to fulfill at least
the requirement concerning "master-like" skills in your craft. This still is controlled by the chamber of trades. A
master is a title and a graduation after attending 3 years as a apprentice follwed by the graduation as assistant.
After some years of practise one can attend for the master graduation after one or two more years school and
lessons in various branches. Still in some trades the master title is very difficult to obtain like the carpenter and
some other highly appreciated trades.
The admission to run a workshop or examination of your "master-like" skills still is an affair of the chamber of
trades in Germany.
The situation still is very strange in this trade because steel string guitar making is not a individual trade. So my
master's examination was conducted by two classical makers, a zither maker, a violin maker and a younger steel
string guitar maker fellow. Absurd enough. But I took this whole matter very seriously. At the examination we
had to craft an old fashioned head dove tail joint (the same joint Martin head stocks had until the early 20th
century). So it was not only to fulfill the official requirements.
As CF Martin senior left Saxony, Germany, in 1833 the cabinet maker's guild (he belonged to) and the violin
maker's guild had a quarrel over several decades in which Martin's father was involved before him. The
generation of Martin's father was the first to build guitars at all so it was a brand new instrument at this time.
Since the times were hard for all, the violin makers and the cabinet makers reclaimed the sole right to build
guitars or in other words, the violin makers wanted to prohibit that anybody else was building guitars. For this
reason the violin makers filed several lawsuites but all were dismissed.
It is very likely that CF Martin senior left the country for several also private and commercial reasons, the guild's
long-reigning quarrel could be looked at one main reason for him to emigrateto the US.
Willi
Author
Comment
#52
[-]
Quote:
But surprisingly the back arch at nicely arched '30s Martin backs is crosswise nearly the same than lengthwise .
Quote:
Willi, that has not been my experience. I use side profiles from prewar Martins, and they don't have enough
'rise' in the waist area to produce a spherical arch.
BHguitars
(02/01/07 4:49
AM)
John, after posting some pics it may be easier to discuss several types or designs of arches. Looking at the
average Martin back arch of the '30s you are right. The longitudinal arch is less than the transverse arch. Also
the back arch at the waist is somewhat stronger in average in combination of a side profile that is not raised
consequently high enough for a uniform transverse back arch. This is valid also for my "favorite" Martin style
back arch of my '36 00-21. But at this guitar the waists are raised more and the longitudinal arch also is stronger
than the average. Other mid '30s Martins show a similar design. But all are miles away from the modern
spherical arch as you say (what is not nice in the end). For my understanding the reason to use this modern
back arch design is because the sanding dish means a simple operation in comparison to the old fashioned arch
construction and levelling by hand. So again a commercial reason at new guitars. This includes the tall back
braces at the lower bout (tall at all) for my understanding (including humidity effected reasons) since the tall
braces hold the arch much better than the flat ones. But poor enough to find tall braces even in small Martins
that would be dimensioned right for a bass guitar.
Some more statements about Gibson/Martin back arches:
The raised waist mainly is a matter of design. The main reason for Gibson not to raise the waist is probably they
just started to manufacture modern flat tops after building archtops. So the development how the Gibson
flattops stepped forward during the '30s could be followed well. The low waist design also is more simple to
craft of course and for my understanding this always was an important aspect at Gibson.
At Martin the proportion of the back arch at the waist and at the first wide brace at the lower bout are
interesting. I often notice that while the waist brace or arch is too high, the first flat brace is too low. We know
that the side profile determines the arch as well besides the arch of the braces. But I guess there's another
reason for this condition: the process that ends in a shallow neck angle and the need a neck reset. The body,
mainly the top, is compressed through the string tension over decades. While the top at the waist and around
the sound hole is pressed down and sinks in the whole body is twisting at the waist for my understanding. So
the process of the compression of the body happens as follows: the top at the waist and sound hole is sinking
down (for this reason the top should be arched at this place), the waist at the top side angles and twists a little
for this reason to follow this process. The opposite pressure at the back side leads to changes at the back arch
as well plus the rotating of the neck block. These forces lead to a tendency to raise the waist and to press down
mainly the first flat back brace. This explains why Martins that show the sunken-in condition of the top plus
shallow neck angle mostly show a raised/sunken in condition of the back as well. Possibly for this reason the
back arch of the '36 00-21 is still perfect including top condition, bridge, neck angle and so on.
Author
Comment
As I have noticed and also wanted to document throgh the pics is that the intended string tension stands in
relation to the back arch and also to the longitudinal back arch. While the early steel string Martins don't have a
real longitudinal back arch the '30s have. The '34 0-17 back arch shows that they overdid possibly here and
there or looked out for several designs. Possible also that the stronger back arch of the C/R arch top models had
something to do with this. The reason for stronger back arches at higher string tension are more than one: one
is because of firmness to resits any body deformation and compression, the other is to reflect the more
powerfull top vibration beside all sound preferences. Since the back works also as reflector or sound chamber,
it has to be more solid the higher the string tension and the more power the top vibration has. One method to
enhance this firmness is to add arch. This way the back won't be heavier or stiffer. For my understanding a nonarched surface or board does not have any welcome vibration attributes (also for this reason the top should be
arched). An over-arched board may be over-stressed and will be to rigid. But there's a spectrum inbetween that
differes according the intended string tension and the expected power of vibration.
In the end there will be also several different designs for arches with different sound expectations. The
inventions of the Larson Brothers tought us that a strong arch could gain in surprising sound and construction
qualities. They called there arched body design "built under tension" (at least Rob Hartman did). This means the
arches cause a top and back tension that leads to a very clear and full sound character with bass volume and
lots of trebble and overtones. Another Larson invention is the double rod system they use to reinforce the
bodies (at the Prairie State guitars). This construction shall effect less stess at the top and a free top vibration.
Both seems to be true as far as I can tell. Plus Larsons don't need a neck reset in most cases.
I don't think it may be a good idea to mix up several successful and great guitar designs but we can learn
through them. While the whole arch matter could fill books easily one thing could be resumed: top and back
arches are most important for construction, design and sound reasons and should be treated accordingly.
Willi
FoolForWood
#53
[-]
Pfew, posting some serious info in the D-28 lounge makes walking on eggs seem simple. Maybe I can recover a
bit in this here luthiers' joint. Can somebody pour me a beer, please.
At one point (late eighties?) Martin decided to change to ridiculously tall lower back braces. According to John,
this was done during/after a humidity problem at the factory. After the humidity problem was solved, they just
left them that way. If I read Willi right they (also?) could be doing it to keep the arches of the modern (more
pronounced) arch. Ironically, other makers who are using modern stronger arches, most of them building
Martin style guitars, don't seem to need them.
(02/01/07 3:31
PM)
Here's a riddle. How many world class luthiers' opinions, and competing factories that do the old Martin thing,
does it take to make Martin get rid of those tall hunks of wood? (Or rotate them 90 degrees).
In America some luthiers lower them on request. Have you ever done that, Willi?
A couple of years ago, a Martin ex-employee posted at one of the lutherie forums about the spherical sanding
Author
Comment
dishes/discs. He had operated the machines. I saved the thread, but I can't find it right now. Strangely, the tops
and backs on my Martins are not spherical at all. Awhile ago I made myself some arched templates. I'll give you
the approx. back arches that I measured just now. Rel. hum. was 49%.
OM-28V (2002).
Lengthwise back arch: 7 1/2 metres (25 ft), heel to waist, then a considerably stronger arched moment at the
waist, then back to 7 1/2 meters all the way to the tail.
Crosswise: 4 1/2 metres (15 ft) lower bout, 4 1/2 metres upper bout, but barely 3 metres (10 ft) at the waist.
OM-18GE (2003).
Lengthwise back arch: 4 1/2 metres heel to waist, then the strong arched bit again, then 7 1/2 metres all the
way to the tail.
Crosswise back arch: 4 1/2 metres lower bout, 3 metres upper bout, and noticably less than 3 metres (my
strongest arched template) at the waist (my estimation: 2.4 m or 8 ft).
Henk
#54
[-]
Quote:
Arnoldgtr
For my understanding the reason to use this modern back arch design is because the sanding dish means a
simple operation in comparison to the old fashioned arch construction and levelling by hand. So again a
commercial reason at new guitars.
The sanding dish may be simpler, but I propose that someone like Martin could definitely use CNC machining
techniques to reproduce the nonspherical arches that were done in the 1930's. For example, I am sure that
Martin today uses CNC to notch the kerfing for the braces, another operation traditionally done by hand
(02/01/07 7:40
PM)
Quote:
This includes the tall back braces at the lower bout (tall at all) for my understanding (including humidity
effected reasons) since the tall braces hold the arch much better than the flat ones.
I believe the tall back braces preceded Martin's use of the sanding dish by several years, but you are correct in
that it helps solve problems when mating the back to a spherical surface. The humidity issue that I described
was told to me by someone who had knowledge of the plant operations, so it is not speculation on my part.
Author
Comment
Quote:
But poor enough to find tall braces even in small Martins that would be dimensioned right for a bass guitar.
They sure look funny in my OM-18GE.
John
Metropro
#55
[-]
John,
Thanks for your information on bracing dimensions. Your information is always extremely helpful. After reading
your comments, I went to the Martin site to check out the specs. It was pretty skimpy, but I did notice several
guitars had scalloped 1/4" bracing which surprised me. The HD-35, Johnny Cash D-35, Nancy Wilson D-35, Geoff
Muldaur 00-18, Ian Anderson 0-28, Joan Baez 0-45, Norman Blake 000-28, and several other 00's. I have heard
several luthiers say they didn't think scalloping 1/4" braces was a good idea, but clearly there seems to be an
(02/02/07 12:02
established market. I would think braces that thin and flexible would give exceptonal sound.
AM)
Chris
#56
[-]
Quote:
BHguitars
(02/02/07 2:24
AM)
They sure look funny in my OM-18GE.
As the Eric Clapton 000-42 came on the market and German buyers bought as much as they could, many of
these guitars came in for checking the brace dimensions cause of poor sound. I always found top and back
braces nearly twice as large as found at original guitars and had no fun in reshaping those to original
dimensions or firmness. Same oversized back braces in small bodies as in D-bodies. It seems that they only had
one program for their CNC router or better should have hired an IT technician who could have done the set up
for one more brace dimension. Same is at Gibson: braces as tall that one could have made two guitars out of
them.
Willi
Author
Comment
#57
[-]
Quote:
BHguitars
(02/02/07 4:08
AM)
I'd be especially interested in a OO-14 fret side profile
John,
I posted the side template of a 1936 00-21 12 fret at this thread. I don't have an exact 14 fret template or copy
on hand. We usually use the 12 fret side templates for 14 fret guitars as well since the profile is nearly the
same, only a little shorter for 14 fret. This profile should give a nice back arch in combination with a '30s Martin
back brace arch or John Arnold's back radius measurements in average he posted in the beginning of this
thread.
I'm also going to shoot some pics of the back and top arch operation steps we will do soon at our current
production batch but this will take a while, I guess 4 to 6 weeks.
Willi
#58
[-]
Quote:
the D-35 with its 1/4" braces are also not tapered but deliver a richer tone.
FoolForWood
Chris,
For some reason I've never been lucky with D-35's. To me they sound less rich than a typical D-28 (apart from
maybe in a small portion in the bass range).
(02/02/07 9:59
AM)
Quote:
I did notice several guitars had scalloped 1/4" bracing which surprised me.
Not only that; they are in the forward position too, on some models, like OM's. (Although the spec sheet
doesn't mention that). Plus the height on OM braces is 1/2" (8/16") vs. 9/16" on the (HD)-35 vs. 5/8" (10/16")
on the (HD)-28(V). And John just told you how important height differences are.
Quote:
Author
Comment
I have heard several luthiers say they didn't think scalloping 1/4" braces was a good idea
I've heard similar things. Fortunately my OM's are still holding up. BTW, you asked about differences between
brace dimensions then (prewar) and now. Although the widths on dreads are the same (like John said), the
braces on old OM's are actually wider than today's 1/4 ". The tonebars only slightly so, but the X-braces tend to
be almost 5/16". (The oldies were from an experimental phase, though, so there may be some exceptions).
Steve,
Thanks for the support down yonder. You didn't have to do that, but I do appreciate it.
Willi,
I'm studying your latest pics and all the info that came with it. So much to swallow and digest. This is NOT a
complaint BTW. I will follow up on it.
Henk
#59
[-]
John Platko
Thanks for posting the side template Willi.
I'm still having trouble visualizing exactly what Martin was going for in their vntage top and back arching but I'll
keep going over this thread and I'm sure I'll understand it better.
I also have difficuilty understanding the advantages/disadvantages of the vintage Martin arching vs the modern
(02/02/07 10:41 spherical arch. Except from a simpler manufacturing standpoint for the spherical arch.
AM)
FoolForWood
#60
David,
I forgot to ask. Why didn't the Google machine translate "Wilhelm Henkes" into "Hank Williams"?
(02/02/07 11:18 Hank
AM)
[-]
Author
Comment
Metropro
#61
[-]
John did a very good job explaing the affect of height and width on stiffness. Is there an estimate of the
differing stiffness of scalloped braces vs. non-scalloped?
The vintage braces swoop down dramatically in the center and are beveled inward from the sides. So there isn't
going to be a simple mathematical calculation you can use. Is the total 50% less stiff? 60%?
The same question applies to the scalloped 1/4" braces. I'm sure the intent is to get a similar affect as the
scalloping on the 5/8" braces, but given the narrower width less must be taken off the height. I would like to
(02/02/07 12:21
see pictures of these 1/4" scalloped braces, if anyone has them. And know how much wood has been shaved
PM)
off. And, since I've never heard any of these guitars, what people think of the sound.
Chris
#62
[-]
Quote:
BHguitars
The same question applies to the scalloped 1/4" braces.
Chris,
what is your intention behind your question? As you say, there's no simple mathematical calculation possible.
The shape of the scalloping always is similar, the dimensions are not depending on what guitar you are referring
to. The stiffness or firmness depends also on wood quality and how the ach (if there is any at all) was
(02/02/07 12:57
constructed. Also it does not make sense to understand scalloping simply as loss in stiffness. This doesn't hit the
PM)
point. Scalloped brace design is a complex construction that cannot related in % to a non-scalloped brace
design. This is only playing numbers. Or do you consider to have your D-35 scalloped afterwards? A rescalloped
D-35 sounds terrible for my ears.
Willi
FoolForWood
#63
[-]
Chris,
Quote:
he same question applies to the scalloped 1/4" braces. I'm sure the intent is to get a similar affect as the
(02/02/07 12:57 scalloping on the 5/8" braces, but given the narrower width less must be taken off the height.
PM)
If I understand your question, I think you mean 5/16" (wide, that is, or do you mean 5/8" tall?). In that case I
Author
Comment
can say this. The whole idea is NOT to get a similar effect IMO. By thinning, scalloping and shifting, they want to
loosen up the top. This is exactly why the luthiers you (and I) spoke about, get worried if taken to far.
Quote:
I would like to see pictures of these 1/4" scalloped braces, if anyone has them.
I don't have pictures of mine, but I did describe them in detail in an earlier thread. I could quote the whole thing
here, but it would use up quite some space, while it is not ALL relevant for this thread. When I posted it and
asked a question about it, Willi uttered the now famous words:"Please have mercy, Henk". It seems he is taking
revenge now.
Anyway, if you'd like to read it, go to the Tech Info section. Then go to 2nd page of the bridge plate thread on
page 8. I've tried linking threads before, but somehow I screw up every time. Linking to other websites etc. is no
problem anymore.
Hope this helps.
Henk
P.S. Do you actually own a D-35? If so, I didn't know that. I hope my remark about not having luck with the
examples I've tried, didn't make you feel bad about yours. That was certainly not the intention.
#64
[-]
Quote:
BHguitars
I also have difficuilty understanding the advantages/disadvantages of the vintage Martin arching vs the modern
spherical arch.
(02/02/07 1:19
PM)
John,
A back arch construction is something that has to be developed. If you start to construct and design a back arch
you will see that this is a difficult job. What I wanted to show through the pics is that the arch construction is
standing for my understanding in relation to the string tension and the sound character you want to gain. Look
through the pics and my/John's explanations. At least there are more than one arch designs. All have their
advantages and disadvantages. That's what we try to discuss here. Disadvantage for the modern tall Martin
back brace design mainly at the lower bout is a too stiff back for my understanding.
Every maker has his own construction and design that he feels works best for his guitars. We at example prefer
less weight but higher tension or stiffness. We try to gain this through arches and other construction details like
light but solid woods, firm bracing that still allows enough vibration, mortised braces and bridge plates, only
Author
Comment
hide glue joints and so on. The arch is a main part of the total construction but also has its influence to the
sound quality and character. But the arch should look also nice and uniform and should prevent the wood from
cracking.
I will post some more pics and info and try to explain why we do the arches the way we do. But this is not only a
theoretical matter. It works for us since the result is fine for what we try to gain. But this is not valid or selfevident for other makers or constructions. It is part of a whole design and works mainly altogether. So one has
to start and to find out for his own how will work for himself.
Willi
FoolForWood
#65
[-]
Willi,
I have many questions and remarks, but I'll try to do them one at a time.
(02/02/07 1:36
PM)
Both you and John are not huge fans of a completely spherical arch. I could lift out the quotes, but I don't think
that's necessary. Yet, you're favourite back is on the '36 00-21 Martin. To me, but maybe I'm wrong here, that
one approaches a sphere more than all the other Martin backs you showed. I am NOT trying to say that's
inconsistent thinking on your part, only that I am not clever enough yet to understand. Perhaps the answer is
already in there in your texts, but could you please help me out?
Henk
Metropro
#66
[-]
Yeah, I do have a D-35 but I've been told that shaving the braces is not a good idea as Willi has repeated.
However, since Martin makes scalloped braced D-35's I thought this was a perfect opportunity to ask about it
and learn a little.
Chris
(02/02/07 1:50
PM)
BHguitars
#67
[-]
Quote:
It seems he is taking revenge now
(02/02/07 3:58
PM)
Henk,
Everything is fine, nothing to worry about. But as you know I'm not a big fan of taking measurements just for
Author
Comment
fun that will lead to nowhere. There always is a question and is an intention behind and the question is what
way the question could be answered best. Measurements are means that should lead to insights but one can
get lost also in counting clouds.
As far as I understand is Chris' question if his D-35's sound could be enhanced through scalloping or reshaping
the braces and what structural consequences are to be expected. Since Chris is a friend and I presume he's
taking care only of his guitar this may be important for him to figure out - and I reply without coercion.
Chris,
There might be several opinions concerning reshaping D-35 or braces of any guitar. For my person I would only
accept reshaving of braces if something is wrong traceable like too high braces like those to be found in many
small Martins that may sound way too stiff. A D-35 are braced weaker from the beginning, so weakening the
brace construction even more may not lead to what is expected. I haven't heard any guitar with rescalloped
braces that I did like. Especially '50s Martin D's were rescalloped often since people wanted to gain the
"prewar" sound. But they had to find a bad sounding guitar in the end (probably some may find the new sound
great but I don't). The nice and typically firm sound of a '50s D was gone but the scalloped sound didn't come
anyway. There's only some more warmth and midrange but less power and attack. So rescalloping if not
intended in the beginning before the top is glued on is not a good idea in my eyes. The difference is it may be
not the same if a bracing system is scalloped before a top is glued onto the rims or after it has been glued on.
Besides this I believe that a scalloped bracing sytem works the best with a top and braces that are not soft. If a
soft top (or without arch) braced lightly is scalloped the sound will not be powerfull as intended - it will be
muddy. The top is not able to reproduce or to reflect the high energy and power of the string vibration. So the
basses and midrange mostly are a weak bark (the bass frequences switch over to the overtones at once) and
the trebles are blunter.
Chris, if your D-35 is braced well - a look inside and some pressure tests will give an answer - I would leave the
braces as they are since they build a working unit since a while. If you want to enhance the sound some special
details like ungrooved harder pins, bone bridge saddle, pressure fret job, bone nut and so on can improve the
sound without throwing off balance.
I'm not a friend of modifications at all since I want to allow every creation to make its way without any
correction that isn't really necessary. Most D-35s work fine and have a special feeling that many people
appreciate. And if it worked for you why want to change it? The only thing I would consider to replace is the
bridge plate since it should be EIR (what I don't like). But although I do like maple plates much more it would be
a hard decission since even a EIR plate mostly works in a '70s Martin.
Willi
Author
Comment
#68
[-]
Quote:
I have heard several luthiers say they didn't think scalloping 1/4" braces was a good idea, but clearly there
seems to be an established market. I would think braces that thin and flexible would give exceptional sound.
It depends on what you want. If you want a dreadnought that sounds good on the first day, then yes....1/4"
scalloped braces will do the job. But if you are building for the long haul (3, 5, or 10 years down the road), then
the smaller braces are not the ideal. All guitars get bassier as they mature. My goal is not necessarily the best
sound when a guitar is new, but one that matures properly.
Scalloping a D-35 is not recommended because it adds bass and reduces treble on a guitar that is usually bass
heavy to start with. The biggest mistake made when scalloping braces is to go too far.
Quote:
Arnoldgtr
I've heard similar things. Fortunately my OM's are still holding up.
(02/02/07 4:08
PM)
Of course, OM's and dreadnoughts are totally different animals. Santa Cruz has used 1/4" braces on all models
from day one, and IMHO, their OM's are consistently better than their dreadnoughts.
Quote:
I also have difficulty understanding the advantages/disadvantages of the vintage Martin arching vs the modern
spherical arch.
You must understand the properties of wood, and how it affects the function of the back. The back needs some
crosswise arch because wood shrinks and swells across its width. The arch allows the back to shrink without
going completely flat. A flat back is much more likely to crack.
A spherical back arch has more longitudinal arch than is necessary, since wood shrinks and swells very little
along the grain. The back is under tension from the strings. The extra amount of longitudinal arch invites a
flattening of the back from string tension, which can affect the neck angle adversely.
John
Author
Comment
#69
[-]
Willi,
The revenge thing was a joke, of course. As far as I know you, the whole notion of revenge is nowhere to be
found in your system. And it had nothing to do with Chris. What I meant is this. When I posted the info about
my OM's, I buried you, and the other experts to whom my question was addressed, under a huge load of
information. That's when you said, "please have mercy". The last couple of days you offered us an
overwhelming amount of pics and info (great, don't stop doing that!). That's why I said you were taking
revenge.
FoolForWood
John,
Quote:
Of course, OM's and dreadnoughts are totally different animals.
(02/02/07 4:43
PM)
Same scale length and almost the same lower bout width. So is the difference mainly in the narrower waist?
And do the shallower and consequently stiffer sides offer more resistance to the folding in?
Quote:
A spherical back arch has more longitudinal arch than is necessary, since wood shrinks and swells very little
along the grain. The back is under tension from the strings. The extra amount of longitudinal arch invites a
flattening of the back from string tension, which can affect the neck angle adversely.
Of all of the Martin pictures, Willi picked out the '36 00-21 as his favourite, as far as back arch (and top arch) is
concerned. Would you have picked the same one, and if so, why?
Henk
BHguitars
#70
[-]
Quote:
The extra amount of longitudinal arch invites a flattening of the back from string tension, which can affect the
neck angle adversely.
(02/02/07 4:50
PM)
John,
as you will know about my high esteem concerning your ideas I guess this is a (minor) point we obviously do not
Author
Comment
agree as far as I understand.
For my understanding is:
- the longitudinal arch also determined by the transverse arch. The back moves up and down only across the
grain as you say correctly. But what happens if the back is moving up across the grain: the longitudinal arch will
go up as well.
- Arch always adds firmness and resists better agains twisting and deformation. So I'm convinced that a stronger
longitudinal back arch is much more solid against neck angle problems. For this reason the longitudinal arch
was enhanced at the post 1930 Martins as I intended to explain through my pics. Besides this: a flat surface
could be bent easily, an arched surface not.
- So for my understanding the back arch at the upper bout including the area next to the neck block is one of
the most important construction features of a back arch referring to neck angle problems. This is proved since
many years through the Larson's constructions. Also the better '30s Martins have a more pronounced arch
including the longitudinal arch for my opinion.
I do like a noticable longitudinal arch - although somewhat less in radius than the transverse arch - that creates
a nice and uniform arch together with the transverse arch. The sanding dish doesn't take care of the areas
where the arch should run to a nice level at example at the blocks. The sanding dish simply creates a round
surface that looks very strange at several places since a guitar's back is not like round surface. But the right
amount of a longitudinal arch is very important for my understanding for a solid steel string construction.
Willi
#71
[-]
Quote:
BHguitars
The last couple of days you offered us an overwhelming amount of pics and info
Henk,
Indeed I was not sure if this was overloading but I was sure it won't keep you from running through. It was not
my intention but could have been like "no mercy" for you since there are other threads you are digged into
deeply. BTW, do you have a daytime job?
(02/02/07 5:00
PM)
Best,
Willi
Author
Comment
#72
[-]
John already mentioned he "feared" more rotating of the neck block, because of too much arch, especially in
FoolForWood that area. I believe it was somewhere on page one already. So I did think there was a discrepancy between the
two masterminds. That's why I asked John to pick out HIS favourite guitar from the pics.
(02/02/07 5:33
PM)
Pay attention folks. Now it's getting REALLY interesting. And I'm not saying this for the sensation of a battle.
Wrong word altogether. But imagine two great luthiers, both of them building world class instruments. Now
there's an issue on which they don't seem to agree. But instead of hiding with their own little trade secrets (as I
said before; that's for the B-category), they are going to discuss the matter. And what's more, they do it right
here in front of us. We are witness of a special moment. And you know what? After the fact, at least one of
them, but probably both, will make even better instruments than before. Hard to imagine, but not impossible.
How cool is that?
Henk
#73
[-]
Quote:
BHguitars
they are going to discuss the matter
Not sure if there's anything to discuss but I can say I'd be glad to learn.
I really don't have any idea what your daytime job is, Henk. But now I have a suspicion ...
(02/02/07 6:01
PM)
bassrun
Willi
A referee? I'd say more like a promoter....
--John
(02/02/07 6:40
PM)
#74
[-]
Author
FoolForWood
Comment
#75
[-]
#76
[-]
OK, how did you guys find out?
And who turned my head upside down?
Henk
(02/02/07 7:02
PM)
Steve Frost
Quote:
BTW, do you have a daytime job?
(02/02/07 9:48
PM)
Willi- it's funny you should ask that of Henk, because I had the same question. A while back I was going to ask
him, "Are you a muleskinner in your day job?"
At the time I refrained, because I didn't want the remark to be taken the wrong way. But now- there's enough
history to make my jest clear. Henk, whatever it is that you do, you surely manage to keep a thread perking!
BHguitars
#77
[-]
Quote:
Henk, whatever it is that you do, you surely manage to keep a thread perking!
(02/03/07 6:37
AM)
That's what I look at it as well, Henk. But I'm wondering how you find the time, energy and special knowledge.
There is much more background and theoretical understanding than many makers and professionals have but I
guess you have another profession?
Willi
FoolForWood
#78
[-]
Steve,
You can call me anything you like, from muleskinner to slave-driver and beyond, as long as your intentions are
good. I know they are, so don't hold back, pal.
(02/03/07 7:43
BTW, how do you do those nice fat letters? Basic stuff, of course, but I'm a beginner with these things. I always
Author
Comment
AM)
use capitals to stress words, as I think it's important that people read my sentences the way I had in mind. But
sometimes I get the idea it looks like shouting, and that's not the intention. (Mostly). Oh, and while I'm at it,
how do you insert emoticons afterwards? There should have been a smiley behind the word "pal".
To all. OK, I might as well admit. You've heard of the administrators and the moderators; I was hired as a
MOTIVATOR. Much work and lousy pay, but hey, it's a job.
Back to arches. Let me see if I can put the dilemma into simple words.
A straight piece of wood CAN stretch, but only little or as much as the wood allows. However, an arched plate
can "stretch" a whole lot more when it is forced back to it's original flat form. It is then noticably longer from
front to back. If this happens to a guitar's back, the heelblock will rotate, and the guitar (top side) will fold in
(neck reset needed etc.) This, as I see it, is the problem John wants to prevent by not arching too much. That
makes sense to me.
Willi, however, starts from a different point. He figures that arching will make the instrument more rigid as a
whole. That includes top arching, of course, and the relation to the sides. If you imagine a longer than wide, flat
carboard box (with cereals or whatever) and you grab it at the short ends (eat the contents first) you will not
have much problem to fold it in, somewhat at least. Now imagine the two largest surfaces are arched (convex
arches). That would make the folding in more difficult, or I would think. So this makes sense, too.
Of course we can "solve" all this by saying, "hey, whatever works for you". But let's not do that, or I might lose
my job here.
Henk
Steve Frost
#79
[-]
During this slight lull in the action, I'd like to record some observations. First, I've learned far more than I ever
hoped to when I posted the initial question. Also, there's a beautiful symmetry happening here. On the basis of
the information contributed in this thread, I intend to make a 12 fret size 0 guitar, using the patterns and side
profiles that Willi supplied, as well as a red spruce top that I bought from John Arnold a couple of months ago.
Thanks to both for the enlightenment!
(02/03/07 11:24 Henk- we'd really like to see a significant show of numbers in this thread, or else we may need to reassess your
PM)
reimbursement package. Just a word to the wise. It's showtime!
FoolForWood
#80
[-]
Steve,
(02/04/07 8:05
Will that be a double or single 0? The plans and side pattern are for a 00. Early single 0 had a single tone (and
finger braces) plus a cleated centre seam. This reminded me of a nice thread from last October, about the
restoration by T.J.Thompson of an old 12 fret 0. I looked for it, but again, there is a hiatus between page twenty
and the most recent archives. Who does this archiving? Anyway, I then looked through my printed threads, and
guess what? I saved it. And guess who the owner of that guitar is? Chris! (Metropo) I read the whole thing
Author
Comment
AM)
again; what a great story. Also a lot of things fell into place when I saw who the various posters were, and how
they were or got related.
Steve, with those patterns from Willi and the red spruce from John, plus their expertise and your experience
from earlier builds, I'm positive that is going to be one fine guitar. Keep us posted!
BTW, for details on a complete guitar I can recommend the Ted Davis 1-18 plan, that I spoke about earlier. It
does have a totally flat top, but the drawings are very useful IMO. It can be ordered from the Guild of American
Luthiers, but LMI also has it. The "1" is a sugarsweet model. The smallest with a full 24.9 scale, and it's a little
deeper than some larger models, especially relatively speaking.
About the showtime. Mmm. I guess I'm not the only one who's putting some pressure on. OK, then, a little
more about myself. I actually did elaborate on this somewhat in my forum introduction on the tenth of
December. But that thread is also between two stools now.
[ This part was deleted by me. I left the text on, until daytime all over the US. (As we are a little ahead here in
Europe). Those who missed it and still want to know more about me (please, don't expect too much, I'm only a
lowly woodfool) can leave a message in my inbox. Steve and Willi, I will mail anyway.]
I will add that I really do like to share and to motivate people, and to bring them together if I can. Some have
the will, but just need a little push. In that there's the risk, of course, of pushing too hard or sticking my nose
where it shouldn't be. I try not to cross this line, but if I do, please let me know and I'll back off.
Now can we please get some answers on the pros and cons of back arching, especially in relation to heelblock
rotation?
Henk
#81
[-]
Quote:
BHguitars
Now can we please get some answers on the pros and cons of back arching, especially in relation to heelblock
rotation?
(02/04/07 4:03
PM)
Henk,
Very interesting question worth to be figured out more clearly. I thought about it how to proceed and also
about John's construction basics in this matter as far as I understand. I'll look if I can create a drawing to
illustrate the forces and pressure points that effect deformation and a twisting of the neck angle for my
understanding. This should direct back to our discussion about arches meaning how to create a body that is
more resistant against body compression, deformation and neck angle problems.
Will take a while to do ...
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Comment
Willi
FoolForWood
#82
[-]
Willi,
(02/04/07 5:25
PM)
Take your time. There are bound to be more urgent matters going on in your workshop. Maybe we can discuss
some other, less time consuming, bracing or arching stuff in the meantime. Your posts and pictures offer a lot
to think about. Now let's hope I didn't scare John away.
Henk
BHguitars
(02/04/07 5:43
PM)
#83
[-]
Henk,
What I have mentioned before: I guess not everything is possible to discuss controverse since I don't feel
there's a right or rong or black and white. You know there are several well working designs based on excellent
construction. Since it may be difficult to isolate some of it's features it is more helpful to look at the entire idea
and construction basics and try to understand how and why they work. Also there's a lot of "learning by doing"
besides all theoretical discussions and conclusions.
While it seems that some basics of our top and back arch construction differ to others or may differ to John's,
this doesn't mean I wouldn't consider his construction less working than ours. It may work only different but
the best as possible for him. But in the end there maybe nothing that I would appreciate higher than John's
experience and constructions.
Willi
#84
[-]
Willi,
FoolForWood
(02/04/07 6:56
PM)
I believe one never stops learning. Especially the great masters from the past said this, even some when they
were ninety years old. Of course, at that moment their instruments had already been fantastic for many
decades, but that's not the point. One way of getting better, is using your own brain, and keep thinking on how
you might improve things. Another way is communicating with others. This can help in a direct way by using
each other's ideas, or indirectly, when you don't copy but get a fresh kind of inspiration, so you do your own
thinking but start from a different angle.
This communication makes the most sense IMO if you can do it with someone of your own level (approx.). It
also helps when there are different viewpoints (disagreement was a wrong word, maybe) or you won't have
much more to discuss than:"Yeah, that's right, that's the way I see it, too. Good day now." But that's way past
"right or wrong" and "black or white".
If ever the old masters wanted to communicate with anyone outside their direct environment, they had to
Author
Comment
travel or post letters. Both took a very long time. This is likely one of the reasons why they often flocked
together. We recently wrote about the area where CFM 1 originated from. And similarly there was the
Cremona area in Italy etc. Today, luthiers can be continents apart, but they have the internet to learn from each
other, or at least to inspire each other. Wouldn't it be a waste not to use it, especially for sorting out those
"last" little details?
That's sort of what I meant when I said a special moment had arrived. I admit I spiced it up a bit. I like to do that
sometimes, along with a little humor added if possible. This place is also about having some fun or a good time,
isn't it? But I am sincerely enthousiastic about the idea, especially since, unlike in the old days, we can all be
at the scene.
Oh, and by the way, when I was asking everybody's attention for the debate between the two great luthiers, I
DID mean you and John. And I did NOT mean your body length(s). But I see you like a little jesting, too.
Henk
John Platko
#85
[-]
So if I understand this correctly, pre-war Martins got a lot of their top arch from humidity control and their top
braces may or may not have also been arched. These tops were mounted to straight sides. The back arch was
formed by shapeing the sides. These varied but some started comming close to spherical.
(02/05/07 10:15 Is this correct?
AM)
#86
[-]
Doesn't seem like a bad summary to me, John. All I would add, is that the back braces WERE (and are) arched in
advance. But this only helps crosswise.
FoolForWood
The backs approaching a sphere (although not quite) seem to be in the minority. Most have this noticable bend,
or subtle kink even, near the waist. I already planned to go into this today. Back soon
Henk
Edit:
(02/05/07 10:41
Quote:
AM)
These tops were mounted to straight sides.
There is a slight possibility they beveled the sides a very little, from the waist to the heel, to match a slight
backset of the neck. But I don't think so. Besides, there are other methods of solving this problem. Others may
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chime in on how this was handled. (If at all).
#87
[-]
Hi,
This is/was indeed a fascinating thread. I was tipped off to it by Paul Asbell and frequent mostly the APM forum.
I took a lot of notes! Wonderful info.
Andre Guitar
To pay you back, and since I speak German, I thought I would do Google better and give you an accurate
translation of the GErman quote on page 3 of the thread:
"Wilhelm Henkes, der einige Jahre zuvor mit dem Bau von Saiteninstrumenten begann und danach die
Meisterprüfung als Gitarrenbauer ablegte"
It says:
Wilhelm Henkes, who began building stringed instruments some years ago and subsequently went on to
(02/05/07 12:45
complete his qualification as a master luthier and builder of guitars."
PM)
That, I feel, better reflects the content of the German text!
Thanks again for the tremendously educational read!
Best,
Andre
BHguitars
(02/05/07 1:05
PM)
#88
[-]
John,
As you say the top side profile was almost straight. The back arch is constructed through the arch of the back
braces as Henk explains. I will add more pics as far as our current batch proceeds. For this purpose I'll show
waht is going to be a 12 fret '30s style 000-45 that will be something special (I plan to keep it).
Here is the side profile. Above our normal side template is shown. It is designed for a stronger arch. I plan to
use the back arch from my 1936 00-21. This is something unique since there is no 12 fret 000 size having such a
strong arch in existance as far as I know or what I can use. So I took basically a 14 fret 000 and mixed it up a
little with this profile I just copied of the '36 00-21. The top arch will be the same as we do usually at our guitars
meaning longitudinal and transverse with the highest point at the X-center place. The top sides are facing
against each other at this pic. It is visible that I slighty "scalloped" the places were the arch of the upper and
lower bout will be placed later. The waist place is not raised extra. So with the exception of the lower and upper
bout arch the top side is straight and one level. The back sides show a similar profile but the places were the
lower and upper bout are placed are stronger "scalloped", the waists are raised and the places at the blocks run
out straight:
Author
Comment
Large image
Here are sides bent and placed into the mold. First the top side. It is well visible that the sides are exactly one
level except the lower and upper bout:
Author
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Large image
The back side look. The waists are raised clearly. From this point of view it is also visible that I made a mistake in
copying the side template to my sides obviously left and right from the end block place half way to the lower
bout. It looks that there are slight edges and the surface is not auniform line in the cross over section to the
lower bout. I have to level this places again and will correct my new template.
Author
Comment
Large image
Next step will be the back bracing. Here is the back just glued together. No center strip still:
Author
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Large image
Next step is to glue on the cover strip from the inside. While glueing the strip we use our mold for the top arch
and bracing. This way we can add a slight longitudinal arch at this operation step:
Author
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Large image
The center strip will be routed and inlaid later with some pressur. This way we add some nature pressure in
transverse arch direction and there is absolutely no possibiltity that there will be a center seam crack at the
back. After this operations the back already will have a longitudinal and trandserse "pre" arch without any back
braces still. Back braces will be added next step. Also the kerfing to the sides.
To be continued ...
Willi
BHguitars
#89
[-]
Thanks, Andre, for jumping in. I'll let you know or/and please correct me if my English will run out of the line.
It seems while some of you might have a lesson in guitar making I'll going to have a lesson in English language
and speed typing, pic-shooting, up-loading, pre-viewing, posting ...puh! ... editing ...
(02/05/07 1:11
PM)
Welcome to the forum!!!
Author
Comment
Willi
John Platko
#90
[-]
Nice tutorial Willi.
Why were the lower back braces wide and short instead of narrow and tall like the upper ones?
(02/05/07 2:23
PM)
#91
[-]
Quote:
Why were the lower back braces wide and short instead of narrow and tall like the upper ones?
FoolForWood
(The big boys will correct me if I'm wrong). This allows for more movement with a larger glueing surface.
The back is a secondary soundboard, although not everyone agrees. With lower braces, it will vibrate much
more easily, and at a lower pitch. For stiffness, a change in width matters much less than a change in height, as
John Arnold explained earlier. The upper bout is arguably less important acoustically, but has to retain its shape
to resist the rotating heelblock etc. (more on this later).
(02/05/07 4:56
PM)
Furthermore, wider wood (lower bout width) will shrink and expand more than narrower wood (upper bout
width). So the low braces on the wide part will allow the wood to move with humidity changes. With taller and
narrower braces here, there's a greater chance of cracks in the thin back wood, or loosening of the glue joints.
There ARE guitars, however, with four, more or less the same, thin and tallish back braces. Some Gibson models
(old and new) have this. But, like Willi said earlier, although Gibson tops tend to have a stronger arch than
most, the backs are more or less the same, i.e. less arched than some other brands. Loose braces are not
uncommon, though, on Gibsons, but that phenomenon is usually not limited to the two lower back braces.
Another example that comes to mind, is the new Chinese Guild dreadnought.
On modern Martins, the lower back braces are extremely tall, and taller than the upper two, which is the world
upside down.
Henk
Author
Comment
#92
[-]
Andre,
A very warm welcome from me, too. Glad to hear, this thread made you want to join.
Quote:
FoolForWood
I was tipped off to it by Paul Asbell
Good he did that, but where is he? Get him here!
Unlike I said earlier on when we were playing around a little, I do NOT represent this forum. But I do want to
invite more people like you to join, if they like what's going on here. I don't think the other members will shoot
(02/06/07 10:47 me for this.
AM)
So luthiers and (other) passionates, this place is both warm and educating. On some other forums, I've seen
quite a few overheated discussions. In other sections here, it sometimes happens, too (though nothing our
moderators can't handle). This section tends to be easy going (let's please keep it that way), although there is
some serious business going on, as you can see. And there are not whole days between posts. So if you have
something to say or ask, or want to join in a friendly debate, don't hesitate. The more the merrier.
OK, I just took a look in the mirror. The guy in front of me told me to keep quiet now.
Henk
#93
[-]
>>Good he did that, but where is he? Get him here!<<
Paul Asbell
Oh, I'm HERE all right! I've just stayed in lurker mode, as any fool might do when surrounded by folks like John
Arnold and Willi Henkes who truly KNOW something...
(02/06/07 1:50
PM)
I did take the liberty of posting on AcousticPlayerMagazine.com concerning the genuinely fascinating and
informative doings over here on this thread. There's so much to learn about '30's vintage guitar construction,
and there are a great many folks hungry for info on what made these guitars "tick". As a result, there's an awful
lot of imperfectly informed people dispensing information on the topic. It's wonderful to see how an internet
thread can become a repository of knowledge for folks looking to build in the former Golden Era style. With any
luck, this info WON'T fall prey to the same factors that made earlier builders' knowledge almost lost.
Anyway, this thread is MUCH appreciated... even by us who choose only to lurk and learn!
Author
Comment
#94
[-]
You Betcha!!! What Paul said!!
Thanks to Paul for the heads up on this fantastic thread!
And thanks to Steve, John, Willi, Henk, et. al. for posting! This mystery needs lots of 'splainin'.
viv2199
(02/06/07 2:03
PM)
(me in my younger days at the wonderful Al Carruth's lutherie class)
Viv
FoolForWood
Paul and Viv,
(02/06/07 2:27
PM)
Henk
#95
[-]
Author
BHguitars
Comment
#96
[-]
Viv and Paul,
Thanks for your feedback. Nice guitar that you seem to work on, Viv. Looks like a modern 12 fret with some
modern style bracing? Doesn't look to me that this was too long ago. Looks fine!
Willi
(02/06/07 3:21
PM)
#97
[-]
Hi Willi, Henk & all,
Andre Guitar
(02/06/07 3:56
PM)
Many thanks for the warm welcome! And I'm just very grateful that, thanks to "Sir" Paul, as we refer to him
behind his back at the APM forum , I was able to find you, grab a seat, and pay attention very closely. Quite
frankly, I find these topics super interesting, but on the same token, I'm largely ignorant of much of what you
speak. And that's why you won't find me chiming in too often, that's for sure!
I'm just doing my best to understand, and it's a treat in this day and age to come across a true reservoir of
information!
Personally, I've just loved guitars all my life, and I do play as well, but leave the building strictly to others! It still
interests me very much, however, to find out where that wood magic comes from!
So, that's why I'm again very thankful for the nice welcome, and, unless any more German text comes along!
, I'll more than likely remain a very appreciative lurker!
Thanks again! (and thanks Paul too, for the heads up!)
Best,
Andre
viv2199
(02/06/07 7:56
PM)
#98
[-]
Henk,
Thanks for the thumbs up!
Willi,
Thank you also for your kind words. Yes, that's a 12 fret guitar more or less 000 in size, designed by my teacher
and mentor at that time (2001), Al Carruth (www.alcarruthluthier.com). I don't know if you have ever met him
but he is a gem! Kind, patient, so good-natured, with encyclopediac knowledge of many things, especially
lutherie, and one of the best story- and joke-tellers you would ever wish to meet. He has many theories about
bracing and plate tuning.
I am enjoying this thread tremendously. It is a pleasure to "meet" you here! Thank you again for your time,
expertise, photos, and discussion. I'm staying tuned.
Best to all,
Author
Comment
Viv
Paul Asbell
#99
[-]
>And I'm just very grateful that, thanks to "Sir" Paul, as we refer to him behind his back at the APM forum<
Hmmm... probably best to KEEP it behind my back. Don't want to be getting the "big head", ya know....
(02/06/07 8:18
PM)
OK... back to lurking.
#100
[-]
Quote:
So I took basically a 14 fret 000 and mixed it up a little with this profile I just copied of the '36 00-21. The top
arch will be the same as we do usually at our guitars meaning longitudinal and transverse with the highest point
at the X-center place.
Steve Frost
(02/06/07 8:21
PM)
Willi, if I'm understanding you correctly, you are using the side profile of the 00, and adjusting it slightly to use
on a 12 fret 000. That's what I have in mind. I'm not currently working on a 00, but I have an 12 fret 0 and a 12
fret 000 underway, with sides bent and glued to endblocks. The 000 is also made of some special wood, and I
intend to keep it. It's quilted mahogany that I bought from a certain Pennsylvania guitar company about 20
years ago- I think I paid $20. Yes, they were seconds- the sides each had a small crossgrain crack, but very
repairable. Of course, Martin doesn't work that way, nor would I, if I were building it for someone else. But I can
live with it! It looks like lizard skin- in a good way!
Quote:
The top sides are facing against each other at this pic. It is visible that I slighty "scalloped" the places were the
arch of the upper and lower bout will be placed later.
How large a gap did the scalloping produce, between the (formerly straight) top edges? 3mm? 4 mm? Just
trying to get a feel for it. I don't mind finagling, but some actual numbers would be welcome.Thanks to all who
have chimed in!
Author
Comment
#101
[-]
Henk,
I really don't think that Willi and I are all that far apart on back arching. We do agree that spherical arching is
overkill, and that there is a certain pleasing 'look' that we try to achieve. I have built guitars where the sides
have more rise in the waist area, and they work just fine. I just prefer the 1930's Martin design generally. The
Norman Blake 1934 D-18H has more arch than most D-18's, and I generally use arching patterns made from
that guitar.
Willi,
I understand your fascination with Larson brothers guitars. I have only played a few, but the sound is
memorable. They have a projection that reminds me of a good archtop guitar, not surprising since the top arch
is more than most flattops. Although they are excellent guitars, they do not have the Martin sound, however.
Here is an illustration of the spherical back arch, as practiced by Martin today. On the left is a photo of the new
D-18A from the Martin site. On the right is the mystery D-18 that is on Ebay currently:
Arnoldgtr
(02/06/07 9:25
PM)
John
Author
Comment
#102
[-]
More on back brace design.
Henk:
Quote:
Arnoldgtr
There ARE guitars, however, with four, more or less the same, thin and tallish back braces. Some Gibson models
(old and new) have this. But, like Willi said earlier, although Gibson tops tend to have a stronger arch than most,
the backs are more or less the same, i.e. less arched than some other brands. Loose braces are not uncommon,
though, on Gibsons, but that phenomenon is usually not limited to the two lower back braces.
(02/06/07 9:57
PM)
I believe that is primarily a problem with the glue itself, rather than the arching. A majority of Gibsons were
mahogany bodies, a wood that is known for stability. Most of Gibson's loose brace problems (other than bad
glue) were due to the fact that the braces were cut very low where they intersect the kerfing. This is especially
important on the X-braces 'north' of the bridge, since the torque on the bridge tends to depress the
soundboard, pulling the braces loose from the top. Also, the fact that Gibson did not raise the waist area puts
more stress on the ends of the center back brace, since the back is forced into a flat plane on the edges.
John
#103
[-]
John,
Pfheww, man, am I glad your back! I was almost starting to feel guilty, thinking I might have made you lose your
FoolForWood appetite with my ravings.
Quote:
I really don't think that Willi and I are all that far apart on back arching.
(02/07/07 6:26
AM)
I know you're not far apart on anything, when it comes to building great instruments. I just like it so much when
you guys try to sort out those last details, complete with the argumentation of the viewpoints. Details CAN be
important, though.
Anyway, in all of these six pages, sofar, I've found only two issues where the two of you may not be totally on
one line.
1. The amount of arching in the back, especially in the upper bout. Willi seems to prefer significant arching in
both top and back, so the instrument will be rigid enough to resist folding in. (Those are my words; I hope I put
it correctly). When he has the time, he'll make a drawing with the forces pointed out.
Author
Comment
You, as I understand it, like a little less back arch, especially in the upper bout, so that portion cannot get much
longer when it wants to flatten out, and consequently the heelblock will rotate less. It would be great if you
could come up with a drawing of the forces too, but I do realize you are a busy man.
2. You say there's a considerable difference in the amount of arching, between prewar (and postwar?) and
"modern" Martins. Willi sees a considerable difference already between (roughly) twenties and thirties Martins.
(On average; the archtops and Hawaiians even more so). Again, these are my own words, as I understand the
matter.
Quote:
Here is an illustration of the spherical back arch, as practiced by Martin today. On the left is a photo of the new
D-18A from the Martin site.
Can we conclude here, that the back arch on the D-18 Authentic is NOT authentic?
Your elaboration on the Gibson bracing is very clear, as usual. Thanks for that.
Viv,
I have followed Al over the years, when he posted on several forums like the MIMF and Acoustic Guitar. And, of
course, his splendid contributions to the GAL quarterly. I already mentioned him earlier in this thread. There's
another well-known luthier on the forum of Acoustic Guitar, who can get pretty nasty when a "beginner" asks a
question, even if that question isn't addressed to (at?) him personally. Instead of politely giving a short answer,
or simpler, not showing up at all, he then says things like: "Go and do your homework first." Not Al. Like you
said, he is very kind and patient, especially with beginners. If he ever gets just a little stingy (rare occasions) it
will only be with those on his own lutherie level (well, not quite; they're desperately trying to get somewhere
near it), when they are trying to give him a hard time. But even then, he always remains a gentleman. Wouldn't
it be FANTASTIC if we could get him to join here?!
In the workshop, did he go into his own prefered way of bracing the back (X-bracing), or did he teach the
traditional transverse bracing?
I haven't made notes, but I'll see if, from the back of my head, I can come up with some possible pros of Xbracing the back. This IS relevant for this thread (if we include backs at all), but those who are only interested in
prewar guitars or replica's thereof, can skip this part.
1. An X-braced back will have a lower pitch (main resonance frequency). If close enough to the top's freq., the
two plates will "couple" acoustically. If the two are EXACTLY the same in pitch, you will get a terrible "wolf"
tone. (Much energy in a very narrow freq. band). But if almost there, like one or two semitones higher for the
back, there'll be more output over a fairly broad freq. band. That is, if you don't choke the back with your belly.
As the mere stiffness of the hardwoods isn't so much greater than that of spruce, you have to know what you
are doing. Guessing is not enough, you'll have to be willing to apply the basics of tuning here.
Author
Comment
2. It will give a "natural" arch in BOTH directions, even before the back is glued to the sides.
3. Although pitch and stiffness of the back as a whole are lower, longitudinally it is stiffer than a transversely
braced back. This could help resist the pulling and rotating factors in the strung guitar.
Henk
#104
[-]
Hi Henk,
Quote:
I have followed Al over the years... But even then, he always remains a gentleman. Wouldn't it be FANTASTIC if
we could get him to join here?!
viv2199
I agree wholeheartedly! As you mentioned Al sometimes posts at mimf but he also participates at
luthiersforum.com.
Quote:
(02/07/07 1:27
PM)
In the workshop, did he go into his own prefered way of bracing the back (X-bracing), or did he teach the
traditional transverse bracing?
Students worked on a number of different instruments during the 14 months that I attended Saturday classes at
Al's workshop in Dedham, MA (before he moved to New Hampshire). As I recall I think there were two or three
archtops, a neck-through electric guitar, and at least one or two violins and a classical guitar underway during
my tenure. I think that I was the only person in my class working on a flattop steel string guitar at that time so I
can only speak to how Al worked with me on this project. On this guitar we did the Chladni plate tuning - aka
"glitter tuning" - and used x-bracing for the back as well as the top. Some photos from Al's website of that
project follow:
Author
Comment
Author
Comment
Author
Comment
The body and neck have since been finished and have been at the "finish" stage with French polish for quite a
while. I recently returned to this guitar and am not far from completion but as Al always used to say,"90% done
and 90% to go." I love that man!
Quote:
1. An X-braced back will have a lower pitch (main resonance frequency). If close enough to the top's freq., the
two plates will "couple" acoustically. If the two are EXACTLY the same in pitch, you will get a terrible "wolf"
tone. (Much energy in a very narrow freq. band). But if almost there, like one or two semitones higher for the
back, there'll be more output over a fairly broad freq. band. That is, if you don't choke the back with your belly.
As the mere stiffness of the hardwoods isn't so much greater than that of spruce, you have to know what you
are doing. Guessing is not enough, you'll have to be willing to apply the basics of tuning here.
That sounds about right to me, from what I recall!
Quote:
2. It will give a "natural" arch in BOTH directions, even before the back is glued to the sides.
This I wonder about. Could you please explain a little more what you mean by "natural" arch and what
implications this would have?
Quote:
Author
Comment
3. Although pitch and stiffness of the back as a whole are lower, longitudinally it is stiffer than a transversely
braced back. This could help resist the pulling and rotating factors in the strung guitar.
Makes sense to me. I can't recall if Al talked about this at the time.
Thank you for asking and thanks again for this great thread!
Viv
#105
[-]
Viv,
Thanks for posting the nice pics and the words to go with them. Nice coloured letters, too! Is that a woman's
touch?
From what I remembered, the X had narrower legs, and arms that ran into the upper bout. I certainly saw that
somewhere, so I must have mixed the two up. Or do you know if Al has more versions? When the X is "only" in
the lower bout, I guess my #3 remark isn't so meaningful, although it could help some.
FoolForWood
Quote:
Could you please explain a little more what you mean by "natural" arch and what implications this would have?
(02/07/07 3:35
PM)
Since English isn't my native language, I sometimes struggle to find the exact words to illustrate my point,
especially with these technical matters. "Natural" is not the exact word, but I'll try to explain what I meant.
If you use traditional transverse back bracing, the back, before it is fitted to the sides, will basically only be
arched transversely. You can vary the radii on the four braces a little, but the true longitudinal arch will not be a
fact before you press the back to the preshaped sides. Getting these sides shaped smoothly (without the
spherical concave sanding disc), is tricky and asks some experience.
If you use X-bracing, the arching will already be there in BOTH directions, even when still a free plate. Also these
X-braces will have a fair curve, or else they couldn't have been glued to the plate properly. So it is smooth or
"natural" to begin with. As you can see in the recent pics Willi posted, even very experienced luthiers like him,
can get the sides curve slightly wrong. Of course he'll make it right, but it illustrates that it's just not so easy.
With a preshaped back (already curved in both directions) you could even use that as a guide to trace the sides
profile, as I've tried to explain earlier on in this thread. (The way a friend of mine does it).
It could be that I interpret Al's ideas incorrectly. I hope not, but on the other hand, it might lure him to come
over and set things straight.
Author
Comment
Henk
#106
[-]
Quote:
On modern Martins, the lower back braces are extremely tall, and taller than the upper two, which is the world
upside down.
BHguitars
Henk, good summery! Normal is: the wider the span the higher the brace. Insofar the braces are correct but
way too high at all especially for smaller models. It won't be a good idea to preselect one tall size for the braces
before the entire construction is prooved and ready to go. For the single guitar it makes sense simply to copy a
prefered design (like a pre war guitar). The braces should work for the arch and the hight is determined through
their different tasks. In the end one has to find out how the braces work for the special design. But it is simply
not the intention of the small wokshops to work with any industry designed construction. A craftsman works on
the single guitar and each brace should be dimensioned and shaped as best as possible (and really not at that
height) for the best possible result.
Quote:
How large a gap did the scalloping produce, between the (formerly straight) top edges?
(02/07/07 3:47
PM)
Steve, I measured what I planed off the sides for the top arch at the bouts and got 1 mm for lower and upper
bout each. This may depend also on how much you want to arch your top. I guess this will be the right amount
for a top arch that peaks about 4 mm above the rim level at the center of the top. So it is a stronger arch and
usually we work with a somewhat more profiled side shape. But at this guitar I prefer a somewhat less profile.
Quote:
I really don't think that Willi and I are all that far apart on back arching. We do agree that spherical arching is
overkill, and that there is a certain pleasing 'look' that we try to achieve
John, that's my feeling as well. I especially like your description that the guitars should be light built but solid,
designed for the long run. They need to open up what will take a while in opposite to those guitars that seem to
sound "ready" without any age and milage in the back.
Quote:
Most of Gibson's loose brace problems (other than bad glue) ...
Right, plus the braces are over arched meaning the ends always tend to come loose. The bigger '30s guitars
Author
Comment
seem to have the best braces, they won't get loose too often. Not very pleasing are some banners with their
narrow braces. Surprisingly the post war SJ-200 is braced very well with the braces dimensioned and shaped
well and mortised into the kerfing.
Quote:
Can we conclude here, that the back arch on the D-18 Authentic is NOT authentic?
Henk, It is not possible for my understanding to proove for authenticity. Their might be several ways to pick up
the genuine intention as supposed to be and to transfer it to the present. But one has to be serious. Martin
today has other preferences obviously than to research traditional craftsmanship.
Quote:
Could you please explain a little more what you mean by "natural" arch and what implications this would have?
Viv, nothing too important but I'll try to explain what I meant: the back arch is gained through 1. transverse
through the curved braces and 2. longitudinal through the side profile (look at my pic above showing the sides
in the mold) plus the previous transverse arch in the moment when the back is glued to the sides. I guess so far
everything is clear. Now I don't won't that through any operation my back will curve the wrong direction
meaning concave. So I create my operations this way that the back will show a slight "pre" arch the right way
before it is braced and glued on: while the center strip is glued on I press the back into our concave top bracing
mold. After the glue is dry there is a slight longitudinal arch. Second step I route the slot for the center strip and
the strip will be glued into using pressure. This pressure bents the back slightly transverse. So what I get is less
energy needed when I brace the back and glue it onto the rims. This I meant with "natural" arch since I didn't
arch actually.
Willi
FoolForWood
Willi, I believe Viv quoted me there, but I entirely agree with your explanation.
Henk
(02/07/07 4:00
PM)
#107
[-]
Author
BHguitars
Comment
#108
[-]
I just realize but I recalled I explained something similar before - not referring to Viv's X-braced back.
(02/07/07 5:36
PM)
#109
[-]
Yes, I think it's this:
FoolForWood
Quote:
The center strip will be routed and inlaid later with some pressur. This way we add some nature pressure in
transverse arch direction and there is absolutely no possibiltity that there will be a center seam crack at the
back. After this operations the back already will have a longitudinal and trandserse "pre" arch without any back
braces still.
(02/07/07 6:51
PM)
Weren't the originals made with the centre purfling glued between the halves? Personally I would prefer the
routing.
Henk
#110
[-]
Quote:
BHguitars
trandserse "pre" arch
This might be a brand new technique or trade secret, I never heard about this before
.
Quote:
(02/08/07 3:18
AM)
Weren't the originals made with the centre purfling glued between the halves?
I would suppose this was and still is the standard way but the actual result may depend on how one glues the
halves together. Formerly we glued the back seams (including the strip in between if there is one actually) the
same way we still do the top seams. But this technique may have the disadvantage that the back seams (not the
Author
Comment
top seams) may open a little or develop a small gap at the center strip near the edges over the years as
sometimes seen at old Martins caused by the forces when the backs are glued onto the rims.
This technique is even simpler and faster since one does not have to take care of the center seam since it is
routed off actually (but the inside cover strip has to be perfect). When the center strip is added it will be fitted
perfectly into the slot with a little more pressure at the center and a little less at the edges. Works perfect. This
is one of those construction details that are surely not the same as pratised these days but it means a step
forward for us at this detail. So it is not a must for us to work exactly how it was practised before the war. What
we try is to understand what and why things happened and how they were practised and try to move forward
from this level of construction and workmanship.
Willi
FoolForWood
(02/08/07 11:08
AM)
#111
[-]
I also believe it's the better way to go. Also, for the cheap among us, this way you can make two thinner strips
out of one thick one. If the prewar builders had had the easy to handle routers of today, they would probably
have taken that route, too. And CFM III would surely have liked my economy tip. He was the one who checked
the bins at night, to see if there was still any sand left on the thrown away sandpapers. If so, he would put them
(it) back on the employee's bench. Also, he is known for inventing the cut off pieces of copper tube, to serve
as holders for pencils that were too short to handle otherwise. Great stuff!
Henk
#112
[-]
Quote:
Arnoldgtr
Also, for the cheap among us, this way you can make two thinner strips out of one thick one.
Actually, Martin did use thinner strips in the older days. They just glued a piece of Spanish cedar on the
backside to make the strip as thick as the back.
I believe the main issue is the width of the back pieces. By gluing the center strip between the halves, the back
could be made wider. This could be the difference between a 000 and a dreadnought.
(02/08/07 6:16
PM)
Quote:
If the prewar builders had had the easy to handle routers of today, they would probably have taken that route,
too.
Author
Comment
They had routers and shapers in the 1930's.
John
#113
[-]
Quote:
FoolForWood
By gluing the center strip between the halves, the back could be made wider. This could be the difference
between a 000 and a dreadnought.
Funny, I thought about that one, but didn't think it was worth mentioning.
Quote:
(02/08/07 7:28
PM)
They had routers and shapers in the 1930's.
Yes, but were they easy to handle for the more "delicate" work? Did they also use them for the binding
profiles? Then again, it's only seventy years. Sometimes it feels as if we're talking about the middle ages, which
isn't the case, of course.
Henk
Arnoldgtr
#114
[-]
Rather than transporting the router, I would say that the 'factory way' to do this operation is to mount the back
in a jig which is transported across a shaper or router table. In fact, I have 'routed' that slot on a table saw, the
same way the older thru-slot bridge slots were made.
I know that Martin had shapers and/or routers in the 1930's because of the neck dovetail. By about 1933, the
dovetail in the neck block no longer had the saw kerfs through the bottom of the block.
Quote:
(02/09/07 2:49
AM)
Did they also use them for the binding profiles?
I assume that the binding channels were cut the same way they were done much later....with a horizontal shaft
shaper.
John
Author
Comment
#115
[-]
Quote:
BHguitars
(02/09/07 3:03
AM)
Sometimes it feels as if we're talking about the middle ages, which isn't the case, of course.
The tools they used were almost heavier but very well made and constructed. Often I have the idea that the
tools people use today belong to one of this group:
- Computer high tech stuff
- Hot tip special secret tools like the combined electric nose drill and hair trimmer
- Handyman specials of extra fine quality
For the outer binding routing we still use a power routing machine designed for window making that I guess
was made in the '50s. In the old workshop all of our big machines were sort of pre war. OK, I like to use a small
Makita electric drill and I'm glad we have a couple of mini routers for pearl inlays. But my big planer that I use
for all precise surfaces and seams is 100 years old. My old cabinet makers hand book, written in the late '20s,
shows a line of the finest tools one would wish to find in the tool chest today.
Willi
BHguitars
#116
[-]
Quote:
By about 1933, the dovetail in the neck block no longer had the saw kerfs through the bottom of the block.
(02/09/07 3:24
AM)
I thought the sides of the dove tail joint were routed even before the '30s. Maybe I remember wrong but the
pointed end of the joint was round also in the '20s or even before what means routed. But Gibson had the
sawed bottom of the dovetail during the '30s still.
Willi
FoolForWood
#117
[-]
Good info again, guys. I see a great new thread looming on the horizon!
All week I've been trying to get back to those vintage guitars' backs pics, but everytime other interesting things,
both in this thread and elsewhere, stop me from doing it.
(02/09/07 7:12
AM)
One more thing, before I go back to backs: baking tops.
This topic also deserves a long and interesting thread of its own, but I want to mention it now, in response to
Author
Comment
the B&W picture Willi posted on page two, along with the description of traditional drying.
Quote:
As I figured out before the tops (and other parts) are stored up the room were the dry and heated air is passing
by. This way the woods are stored over a longer time space (we do this minimum one year) before they will be
used. When it comes close to the bracing the tops (and backs) will be stored closer to the room heater. Right
before the bracing operation the tops will heated a little by an air heater or placed upright against the room
heater.
A little summery from me about modern drying. Most spruce nowadays seems to be kiln dried to a moisture
content of about 6%. That is already a little drier than the equilibrium it will have in most moderate
environments. But after that some factories and even single luthiers are known to "bake" their tops. These are
placed in a convection oven for an hour or so (a regular oven will take a little longer), at a temperature of about
190-200 degrees Fahrenheit (88-93 degrees Celcius). Some go even a little higher than this, but higher than 215
F or 102 C will leave burn damage. After this treatment, the moisture content is 0% temporarily. The wood will
soak up moisture again, of course. But some of the changes appear to be permanent.
After the new equilibrium is reached, several characteristics have been reported:
-the tops have shrunk a little (permanently)
-S.G. is up to a couple percents lower (permanently)
-the tops are stiffer (permanently)
-resin (pitch) has solidified (permanently)
-the tops are more stable; they will shrink less (permanently)
Also it is said, that this is a new way of doing what always has been done. This is where Willi's story comes in. I
see some similarities, but also some differences:
1. The baked tops are left to rest for at least a couple of weeks. In the old story (traditional way), the tops are
braced immediately after the hottest treatment.
2. The tops are forced to 0% water content. That is bone dry, and then some. In the old way, this virtually seems
impossible, and if it was, that would have given some SERIOUS arching after the quick bracing. (Or things like
fractures, loose joints and odd shapes maybe?). Also, if pushed that far, how would they have controlled the
temperature to remain under that critical 215 degrees limit?
So, clearly not the same thing, but some similar philosophy going on.
Henk
BTW, I've planted a little seed down in the D-28 Lounge. (Dangerous). The thread (I did not start it, mind) is
called "Is the Martin Factory humidified?" Maybe you guys might want to look there.
Author
Comment
#118
[-]
Henk,
I'll reply somewhat later more in detail although I might not have much experience concerning "baked" tops. At
this point I just want to point out the difference I see concerning "baking" and what I tried to figure out above.
A main point is clearly to get the tops in a natural and homogenous way to a low moisture content especially
before the tops are braced and glued on to the rims (and I would add before the entire box is closed and
completed). The reasons for this are clear. My understanding is also that Martin and other manufacturers
worked this way since it was absolutely common and sort of matter of course. I also understand that Martin
gained their top arches this way mainly.
BHguitars
(02/10/07 5:42
AM)
A second main point is to do this in a natural and homogenous way what means: no extremes. It's just the
opposite we try to gain. We believe that it is very important to dry the spruce natural and slowly step by step to
prevent any inhomogeneity, stress or even any collapse. The philosophy is a " homogenous natural dry"
condition for the entire body. This is one major aspect for a best as possible coordination of the attributes of
each part of the body. The content of moisture should be as low or better somewhat lower than the driest
condition the guitar will ever see. But this should be done moderately and not fast or extremely for my
understanding.
The heating of the woods directly before they are glued together only means a moderate temperature (not hot)
and not all the way through the wood meaning only at the surface. This does not have any effect permanently
to the wood. It is to prepare the woods for the hot glue and to compensate a little considering the moisture
added through the liquid hot glue.
Henk, discussing humidity (also at facilities) might be very interesting but you might enter the shark basin at the
D28 site. It is obvious that the big facilities have a completely different understanding how to treat woods and
they must have. Otherwise they won't be able to produce this total numbers or won't be able to produce at all.
But people doesn't seem to take care of it and don't pay attention how wood is treated as long others want
them to believe that everything is the same and "authentic". I guess people simply don't understand about the
differences and mostly don't want to learn about it even if the differences are figured out again and again.
Willi
FoolForWood
#119
Thanks Willi,
And if this was just your preliminary reply, what will the
detailed one be like?
By that time we may want to start a new thread on this topic. Plus one on vintage tooling.
(02/10/07 7:24
AM)
Henk
[-]
Author
Comment
#120
[-]
Quote:
Henk, discussing humidity (also at facilities) might be very interesting but you might enter the shark basin at the
D28 site.
OK then, I'll bring the mountain here.
Quote:
One minor point......the factory is climate controlled and the outside the RH ranges from 20% to 90% , year
round.
BUT thats not the main factor building guitars. The moisture content of the wood is the issue. Martin builds
FoolForWood with wood at 7% approximately. It takes time to see that drop to around 5%, which it does. So your guitars will
naturally settle into their permanent shape. No matter what the rh is when built.
Quote:
Wood has an internal moisture content thats tested with a moisture reader. Martin tries to keep their supply at
(02/10/07 12:47 around a 7 to 8% internal (in the wood) moisture content. Sometimes higher.
PM)
When we discuss , "opening up", we're really discussing the overall drying out of the wood and shrinking in
relative proportions to itself. Even when we keep the guitars at a certain RH in their cases or general
environment the wood continues to "cure" and the cells lose moisture and the resins crystalize. That why
vintage sounds so good.
The right piece of wood, the right crystalization and you have a great sounding guitar. Different piece of wood
and you get different results.
Outdoors in Naz the RH is the 20% to 90% depending on the time of year.
So my point is even when the guitars weren't built in controlled climate, you still got great guitars no matter
when they were made, summer or winter.
Send a Martin out to the rockies and it'll settle at around 4.5% . Send it to California and it'll settle in at 5.5 to 6
%. Keep it in PA and it'll still settle in at a lower internal rh than when it was built.
This is why Rosewood takes longer than Mahogany etc., to mature in sound.
When someone puts their guitars in front of a speaker etc, they are vibrating air and those cells and exchanging
air and rh in the soundbox. Playing guitars alot do the same. the main point is to keep the drying evenly from
inside to outside.
Author
Comment
Opening is another name for curing the wood over time. Drying the resins, drying the entire guitar in proportion
to itself. even if you get an rh reading of 45% in the case and out, you still have a different internal wood
moisture content than when built.
The author of this is a musical instrument restorer.
Henk
#121
[-]
Steve Frost
Quote:
(02/10/07 1:36
PM)
That's surreal! Sounds like a recipe for disaster to me. But then, I'm not a restorer, just a amateur luthier.
#122
[-]
Some more thoughts concerning moisture content of tone wood for musical instruments:
I hope I use the terms in the correct way but I guess it might become clear what is meant. First a little about the
wood cell, water content and wood drying. Fresh cut wood is rather full of water (more or less).
BHguitars
(02/11/07 2:31
PM)
The drying process means (rough): getting the water out of the cell. First, the free water moves out quickly of
the cell cavities. Second is the water content inside the cell walls. When the water leaves the cell walls it will
Author
Comment
start to shrink (in most cases).
To get the moisture out of the wood it should be dried either by air or by machine. Now here it becomes quite
interesting: the diagram above mentiones chemical bound water. What does this mean? It means that this
water is mixed up with a lot of other components found inside the wood: wood sap, protein, starch. Further on:
resins, oils and many other stuff. While at machine dehumidifying only is to reduce any water out of the cells
and cell walls what happens with the chemical components? Well, resins and oils oxidize sooner or later
(hopefully) but the wood sap has to leave along with the bound water or has to change its condition. If the
bound water is removed too fast some chemical components remain inside the wood cell walls and never won't
get out again. The wood always will be "wet" even if the moisture content shows a low percentage. This is one
of the major differences in comparison to:
- slow air drying and
- logging during the zero growth or rest period at fall to winter when there's a minimal content of sap and water
inside the wood cells.
This condition also is determining concerning the moon logged wood. Exactly when the lowest content of sap is
reached at special days early in fall and winter the wood will be logged. Also for this reason this wood is called
"free of shrinkage" wood because the cell walls don't keep much water and sap inside and won't soak up and
swell later when higher moisture is present.
Here also is an answer why machine dried wood always is heavier than air dried wood. A second answer is why
machine dried wood does not sound as air dried wood.
In the end I don't think it is really possible to have all woods at the same dry condition in a modern humidity
controlled factory. The airstreams, when air carries moisture and where and when moisture condenses are very
complex in every building. So it is really not as simple to switch on the machine and read the hygrometers. But
considerung the huge amount of wood needed for these huge total production numbers there's no other
chance than doing it the machine driven way including all disadvantages.
Willi
FoolForWood
#123
Willi,
Where do you find these great illustrations all of the time? I guess my books are getting old.
BTW, what do you and John think of the musical instruments restorer's post? (Bottom of page six in this
thread).
(02/11/07 6:15
PM)
Henk
[-]
Author
Comment
#124
[-]
Quote:
what do you and John think of the musical instruments restorer's post?
Ehem!
Quote:
Wood has an internal moisture content thats tested with a moisture reader. Martin tries to keep their supply at
around a 7 to 8% internal (in the wood) moisture content. Sometimes higher.
I've explained some further thoughts on this matter above. I cannot tell about the % Martin wants their wood
to have but in climate controlled facilities wood has to have a rather low % - lower than normal air dried.
BHguitars
Quote:
Martin builds with wood at 7% approximately. It takes time to see that drop to around 5%, which it does.
(02/12/07 4:15
AM)
After the wood cell walls are dried, they still soak and absorb water meaning moisture out of the surrounding
air in general. But here is an important detail: for tonewood it is very welcome to reach the condition when the
wood cells only have a minimal reaction of moisture fluctuations. To reach this attribute special treatments
during and after logging and drying are requested as described above and below.
Quote:
Send a Martin out to the rockies and it'll settle at around 4.5% . Send it to California and it'll settle in at 5.5 to 6
%. Keep it in PA and it'll still settle in at a lower internal rh than when it was built.
No. A guitar in the Rockies will crack in winter as we know very fast when one doesn't take care. At least there is
a good chance for it. A guitar in Louisiana might look completely different (from time to time the end pin should
be pulled to remove the water inside )
Quote:
Even when we keep the guitars at a certain RH in their cases or general environment the wood continues to
"cure" and the cells lose moisture
Quote:
Author
Comment
When we discuss , "opening up", we're really discussing the overall drying out of the wood and shrinking in
relative proportions to itself.
No, this would be a desaster since the guitar would crack already in the catalog. "Opening up" is a more
complex process, the crystalization of resins only is one part of it but is an important part concerning the
wood's condition.
Quote:
This idea should be applied for a patient
.
Moisture inside the wood cells and cell walls are one major key for quality guitars. And as I tried to explain
above not only to be found only at a special percentage right before wood is used in the factory. The drying
process also is a big factor concerning the alteration processes of the different chemical ingredients of wood
cells. If one doesn't care about moisture and the drying process the wood will crack and stay heavy, it won't
stop to swell and shrink more than acceptable at the completed guitar, the wood will be susceptible against any
kind of deformation. The resins won't crystalize as expected, the wood will stay in a wet and resinous condition,
the grain won't be solid and the wood won't vibrate as expected.
He should take a look at the different attributes of different moon logged wood (of the northern hemisphere).
Wood can be logged at special times spaces and depending on the special lunar time the wood will have special
but different attributes: wood that does not split or crack, other wood that does not burn in fire, or that does
not rod in water and mud, or that does not shrink in rain, snow, wind and sun, or that gets hard as a rock and so
on. Even tropical or subtropical woods like ebony or rosewood it is very important how it is dried and treated
before it is used.
The treatment of wood in the following mostly has a similar important influence on attributes of wood. And this
means far beyond of the RH or simple moisture content of wood at the point when guitars are constructed.
Willi
FoolForWood
#125
[-]
Although there are some interesting aspects in that guy's post, I couldn't make head or tail out of it. To me it
seems he has heard something about it, but has no real knowledge of the matter. I didn't feel much like
discussing with him, because last time I tried, he posted a big picture of a donkey. But some other posters
seemed to be really happy with his explanations. I did post this, with no further comment, for other readers to
absorb:
(02/12/07 11:40
Author
Comment
AM)
Quote:
he property of the air is called the equilibrium moisture content (EMC) and it is numerically equal to the MC
that wood will achieve during drying if you wait long enough and if the conditions do not change. (Example: At
30% RH, wood will achieve 6% MC. So the air has an EMC of 6%.)
Common conversions:
0% RH = 0% MC = 0% EMC
30% = 6%
50% = 9%
65% = 12%
80% = 16%
99% = 28%
This is basic stuff, of course. And I have always thought that this law applies to guitars that are ten years old,
but also to guitars that are seventy years old.
The interesting thing to me is the chemically bound water. "Chemically bound" IMO would mean it is not mixed
or even encapsuled, but that it is in fact no longer there as water molecules (right?). The H and O atoms will still
be there, but another chemical reaction would have to take place, for them to recombine to H2O. (It's been
awhile since highschool, but this I remember). There are possibly all kinds of substances in the wood that carry
the H and/or the O. Even plain cellulose is C6H12O6 (some say C6H10O5).
BTW, I have learned about bound water in wood, the hard way. Several years ago we bought a house. We were
barely living there, when big mushrooms appeared on the walls, floors and everywhere. The house was riddled
with a DRY rot fungus. When all the very precisely fitted cover-ups and cover walls were removed it all became
very clear. You wouldn't believe how disgusting that looked. It just cannot be put into words. The spores, of
course, were everywhere, so even removing the incredibly slimey, woolly and stinking mess was useles. Experts
from far away (who were thrilled BTW) said that even applying loads of hydrochloric acid would be pointless on
the slightly longer term. The fungus must have started years earlier after a water problem like a leak. But once
in this phase it feeds on just about anything. First it "eats" the solids and "drinks" the free water, then the
bound water. I guess you could say it actually MAKES its own drinking water. Not only does it attack the
cellulose and other contents in wood, but also in wallpaper, backings of carpet etc. etc.). When all the bound
water is gone, it uses any small amount of water in the air to survive, meanwhile eating the remains. The more
you put the heating on to "dry" the air, the more this sucker likes it. It loves warmth and it will work extra hard
on destroying your property. Finally, it will sit on ANY material in huge cottonwool-like blobs. The
microscopically thin threads can easily get ten yards long in any direction. And once a mushroom bursts open,
the spores will easily fly several yards.
I could go on with the description, but I'm getting sick again when I think about it. We went to court, of course,
and we won, of course. But that took 1 1/2 years. And all that time we had to live in that stinking house which,
during the time the case ran, should be altered as little as possible. Ask me how I know about bound water in
wood. I still can't believe how this woodfool got tricked into that one. It made me ten years older, at least.
Author
Comment
I realize I'm as far from flat vs arched braces now, as I'll ever be. Just wanted to share the story. Carry on.
Henk
#126
[-]
OK, I took this thread off-track in my last post, so now it's my duty to put it back on. Back to backs.
You've heard of the infamous 14 fret "hump"; today I'd like to go into the back hump. Or maybe I should say
subtle kink. It is not there on all guitars (obviously not on those with a perfect spherical arch), but it can clearly
be seen on some. It has been suggested that Martin uses spherically dished sanding discs nowadays. An exemployee even confirmed this on a forum, a couple of years ago. So maybe they did, for awhile. But when I look
at the backs of my Martins ('02 and '03) I can clearly see a stronger bend in the waist area. I've measured it too,
and there is no doubt about it. It can also be seen on some prewar examples. Look e.g. at the pic of the '34 0-17
that Willi posted on page 3 of this thread. The question is, why is it there? Is it there by accident, or was it put
there deliberately? And, in the latter case, what is the reasoning behind it? Let me offer a couple of possibilities.
1. It is put there deliberately to isolate the upper bout back from the lower bout back. The waist already does
this transversely, the kink would do this longitudinally. (BTW, some traditional mandolins, like Martin's bowl
FoolForWood backs, as well as some other traditional stringed instruments I believe, have a very sharp kink in the spruce top).
Isolation of the two areas would make it possible to make the heel area extra sturdy, while the lower bout
could be made more active/responding acoustically. But if this is the reason, what's the point when you are
glueing those huge back braces in that responsive area (modern style)? Also, why don't all the oldies have the
kink? Like Willi showed, there are some pretty smooth curves on some.
(02/18/07 1:17
PM)
2. It is not deliberate, but a less perfectly executed shaping of the sides AFTER the bending. If you follow the
procedure as described in Cumpiano and Natelson's book on guitarmaking, you'll see that they start with a
preliminary arch. And prior to that it even isn't an arch at all, but an angle. First, straight and non-tapered sides
(already bent of course) are glued to the top. Then the angle is cut. When viewed from the side, the lower bout
is left parallel to the top, from the tail to approx. two inches "south" of the waist. From this point a straight
bevel is made, all the way to the heel. Then three "facets" are made, one at the heel, one at the tail, and one at
that angling point near the waist. This results in five facets in total. (Two large and three small ones). Finally the
whole profile is rounded and smoothed to a fair curve. If you do this perfectly, you will indeed have a smooth
curve. If not, you'll still be able to see the preliminary angling point at two inches from the waist (lower bout
side). Just about where it is on the '34 0-17. This could explain the differences in Willi's pictures. (The builders
were only human). But it doesn't explain the kink in the modern Martins that are likely shaped in a high tech
way.
BTW, does John or Willi know, from old factory pics maybe, whether the sides were profiled before the
bending, like most builders like to do nowadays? Somehow I've always thought they weren't, but on the other
hand, Martin has been known to be one of the few to glue the tops on last, AFTER the backs have already been
fitted. This would mean you'd have very floppy sides (without a top yet, only heel and tailblock) to do the
profiling on. Or you'd need very good moulds. Anyway, there must be enough clues in old pics.
Author
Comment
3. If the sides are profiled after the hot bending, there's yet another way to do it. It's like a friend of mine does
it. I already tried to explain this earlier in the thread. I'll have to ask him where he got the idea. In short, it goes
like this. The back, which already has a transverse arch after the bracing, is bent temporarily lengthwise. A
longish piece of wood is placed over the centre strip, and tied to the back (with rope or rubber bands). Then
wedges are placed between the beam and the back, at both ends. This will give the back a semi-parbolic curve
in the longitudinal direction. (Fiddling with the wedges will create the amount of arching he wants). The back is
now arched in both directions and it can be traced to the sides. (There's a trick for that, too).
This way the back wood is bent in a natural way. At the bend itself, the curve will be most prominent. Towards
the ends it will slightly flatten out. On very stiff backs the arch will approach a rounder shape more. On very
floppy backs there'll be a more noticable crease.
One more remark. Over time, the wide portions of the back (upper and lower bout) could flatten out more than
the stiffer waist area. That may look similar, but has nothing to do with the sides profile. In other words, that
doesn't explain the taller waist area of the sides' profile that Willi spoke about on page three, when he posted
those nice pics.
Henk
#127
[-]
Quote:
when I look at the backs of my Martins ('02 and '03) I can clearly see a stronger bend in the waist area
Quote:
BHguitars
The question is, why is it there? Is it there by accident, or was it put there deliberately?
(02/18/07 3:28
PM)
Henk, any kink or stronger/less curve at the longitudinal back arch may not be planned. The side profiles are
designed to result together with the radius of the back braces a nice and uniform arch in all directions - no
matter if one would prefer less longitudinal arch or not. The back arch both directions should fit to the side
profiles. If this is not the case meaning if there is any noticable kink or stronger bend anything didn't work well.
Although there are designs that have pronounced different arches or even kink like flat top mandolins, but if
something similar shows up at a Martin back arch design some mistake could be supposed. I noticed once a kink
at newer Martin tops at the waist to gain a better neck angle with higher bridge saddle but this design is poor in
my eyes and does not replace a well working top arch.
The reason for the kink or different arch you might have noticed, Henk, might be the reason of a back arch that
does not match the side profile cause of false side profile (too high waist) or changed humidity conditions (I
would suppose this). If the humidity changes after the back was braced and glued to the sides the back arch
either gets a kink at the waist (in drier condition) or creates strange bumps like the Recording King shows at the
beginning part of this thread. At old guitars string tension and body deformation (compression) can cause
Author
Comment
changes in back arches as well but these changes that are caused through deformation and not through
humidity changes are complex.
I've prepared some diagrams to explain body compression and deformation under string tension over the years
the way we are used to see at older Martins and Gibsons. But they are not complete already and still will take a
little while. Unfortunately I'm overload with work currently and won't be able to post a lot although I'd like to
do.
Concerning side profiles. If you are going to design a new model you try to figure out a side template/profile
that will work with the back arch you have in mind to create. There are several ways to do. But mostly you work
out something roughly what should do the job (Rudie has built a special tool like a 3-dimensional net to do this)
and check it over when the back is in place later. Then the sides are shaped before bending. When some
prototypes were build you copy/modify the sides once more and make a template out of it. When the template
works and has the correct profile that fits nicely to the back arch, you copy this to the sides to cut out the site
profiles with any kind of planers before they are bent. If you have a sort of serial production (like we had at our
previous company) you'll use this template as a routing template using a copy ring router. This way you get a
hole lot of correct shaped sides. The sides were bent, the kerfing added, levelled and the plates glued on. We
do the back first, the tops at second (we use struts while the plates are glued on to prevent slipping or
deformation. But I guess this is very common). I suppose Martin worked this way always. One could do it also
the other way - top before back - but this doesn't make much difference. Anyway, we prefer back glueing
before top and of course: side profiles cut before bending.
Willi
FoolForWood
#128
[-]
As long as the end result is good, it doesn't matter much how you do it. But out of sheer curiosity, is there any
evidence (e.g. from old factory pics) that Martin profiled the sides before they bent them? Unbent sides with
the funny curve in them would be proof. Bent sides (not glued to the plates yet) that are straight would
disprove it. I keep thinking I saw a pic with quite a few bent sides fitted together to save space. Now where did I
see that one?
(02/22/07 9:44
AM)
BHguitars
Henk
#129
[-]
Quote:
Now where did I see that one?
(02/22/07 10:31 Henk,
AM)
Washburn and Johnston pg. 93 and 98 shows some bent sides but it is not visible too much. I can scan the pics
after work. Also a pic at Carter's Gibson book shows bent rims pg. 102 that I posted before at the Gibson banner
Author
Comment
thread
Here's how our rims looked like recently:
Willi
Author
FoolForWood
Comment
#130
[-]
Yep, it's the one on page 98. I have the book, but must have overlooked the pic when I went through it today.
Thanks. There's a pack on the bench and one on the floor, but you can't really see if they're profiled.
Your rims look promising, too.
(02/22/07 12:05
PM)
Do they all have a new owner, already?
Henk
#131
[-]
All preordered, Henk. But some D-18s/28s and an OM-28 are for Jim Baggett. Available at Mass Street then if
not preordered yet.
BHguitars
(02/23/07 1:03
PM)
Here's the next operation step, bracing of top and back. Here's the top. All braces except the fingers, the
popsicle and the bridgeplate of course are curved and fitted into our top glue mold. The tops have been stored
dry about two to three months now (meaning put out of the wood store rack in the same room and stored
closer to the room heater) as the braces have been as well. Our intention is that the parts are dry but also are
acclimated perfectly. So there's no unexpected stress. The weather and the air are dry since a while - excellent
for the glueing operation. Just before the braces are glued on, the top is additional heated a little by an air
heater but this is only at the surface. This is to support that the hide glue can penetrate the wood pores well.
We glue all braces including the bridge plate in one single operation step. This is a major detail in our eyes. This
means the entire top and its bracing are one unit, no stress, no torsion or twisting. Also, to clamp the braces
this way by using the glueing rack as we name this construction, effects that the braces and the top were not
overclamped and the pressure is controlled and uniform - just enough for the spruce and the hide glue. The
hide glue itself soaks at once into the top pores meaning it soakes the braces onto the top. Not much pressure
is requested.
Here is our molde. I don't know what radius it exactly has. Also I don't think the radius is the same at all places
but basically it will be. But the cross direction is radiused more than longitudinal.
Author
Comment
Author
Comment
This is the top bracing right before the glueing operation upside down to show the mortised or tucked in braces
and bridge plate.
Author
Comment
Now the plate and the braces are glued and clamped. Only the soundhole reinforcement strips will be glued on
in a second step.
The main braces are not pre shaved in any way and still have much more height than necessary. The shaving
takes place later.
Author
Comment
Next operation is waiting soon ... next week.
Willi
FoolForWood
#132
[-]
Fantastic pics, Willi, especially the one with the upside down braces, showing the mortising or tucking in.
It's a whole framework. In your earlier years, did you chisel out the pockets for the plate, tonebars and
fingers, after the main X was on. Or do you know of anyone who does/did?
BTW, what was that about popsicle braces? On prewar Martin replica's? Or do you mean for the 12 fretters?
Or non-Martin models maybe? The one in the pic looks like an OM, but you also do a Larsson OM-type, don't
you? Or is it a 12 fret body in the pic? Not so easy to see.
(02/23/07 3:26
PM)
And how did you make the molds?
Henk
Author
Comment
#133
[-]
Quote:
In your earlier years, did you chisel out the pockets for the plate, tonebars and fingers, after the main X was on.
Or do you know of anyone who does/did?
Henk, the pockets are cut before any brace is glued. One can use a chisel, a knife or a small router. The whole
operation takes only about 5 minutes but will some up if one has to brace hundreds and hundreds of tops.
Rudie usually is doing the bracing and he uses a small router. When it is adjusted it works fast. This time I used
the router as well but I used also my kife or a chisel previously. It doesn't matter too much. A very simple
construction and operation anyway but so well working.
Quote:
BTW, what was that about popsicle braces? On prewar Martin replica's?
BHguitars
This is going to be the 12 fret 000-45 I'm building and I try to go very close to the original bracing pattern I once
copied from the '29 000-28 that Christian now owns. So genuine there was a popsicle brace. I thought about
leaving it off but especially at 12 fret guitars with low sound hole position it makes sense to me since the upper
bout is long.
Quote:
(02/23/07 4:21
PM)
And how did you make the molds?
I cannot remember who actually made this mold but I made others after this one. Very simple: take a thicker
board (I use a chipboard mostly), draw the guitar body outline on it and remove the inside using a scraper and a
small hand sander. The deepest point usually I like to place at the center of the top between X and bridge. It is
important that there are no bumbs. The waist is spared out only a little. As you know we like to raise the waists
somewhat and therefor the waist is integrated into the mold as well.
Willi
Author
Comment
#134
[-]
Quote:
FoolForWood
This is going to be the 12 fret 000-45
Aha, the one you're building for yourself. So that one doesn't have a new owner yet. I think we should talk.
(02/23/07 4:43
PM)
What I meant regarding the molds is, if they're not spherical, how do you make sure the curves in all directions
are fair and left/right symmetrical?
Henk
#135
[-]
Quote:
how do you make sure the curves in all directions are fair and left/right symmetrical?
BHguitars
It's much more easy just to do it than it might seem to be. Only use a template and begin (at least here is the
little difference to CAD directed products )
Now we have talked a lot about top and back arches. While the arches improve the sound they also help that
the body remains in good shape also under (steel) string tension. What the top arch gains at the bridge section
more or less is easy to answer: it simply sounds better and prevents from bridge torsion. The more important
part of the top concerning structure and arch is above the bridge (yes, above - not below besides the bridge
place itself) since an arched surface is much more solid agains compression and torsion. Similar but much more
(02/24/07 12:25 complex is the area around the sound hole and the upper bout.
PM)
To figure out what string tension effects to the neck joint, to the body and to the neck angle - meaning top
compression and body twisting - I want to demonstrate on the basis of some rough graphs (please apologize
the poor drawings, I promise better drawings for the next time).
While the top compression seems to be consequential and comprehensible the deformation and forces
concerning the back and back arch is much more complex and may effect opposed forces that are not easy to
figure out clearly. I try to explain my understanding what of course would be a matter to be discussed.
Here we go.
Author
Comment
We have a normal D-shaped guitar with an average back arch and no top arch as it might look without any
tension or in the beginning.
The string tension and the resulting forces that have an effect to the body are marked red. This should show
very simplified what happens after years when the top is compressed and the body already has twisted. The
neck block including the entire neck rotates and moves forward against the soundhole that is also compressed
from the bridge direction. The upper edge starts to move forward, the neck moves up as shown. The result is
what we all love: a bad neck angle and a high action.
Author
Comment
If we look closer what really happens to the body we will be surprised to see that the entire upper bout is
deformed now. The weakest point is around the sound hole, it is located at the center of two composing forces.
The result is that at first this area is compressed, second is that the flat surface of the top and the braces below
start to draw back and sink in. The place above the bridge is sunken in, the sound hole is sunken in and the fret
board extension presses down the upper bout above the sound hole. The neck block rotates with the angle
point at the end of the neck heel/back. Not enough, what happens to the sides? While the place between
sound hole and bridge is pressed down the waists are pulled inbound. Still not bad enough. While the waists
and the upper edge are pulled inward the sides at the upper bout are pressed outward because of the side
twisting. This would be much easier to understand with a pair of sides already glued together with the blocks. If
the upper edges at the top and neck block and the waist are pressed inside the upper bout edges move
outward and start to "jack-knife".
Author
Comment
Now what happens with a body that is deformed like this and what might happen to the back and the back
arch: while the sides edges at the waist are pulled inward and the upper bout side edges kink there's no
pressure from the top side against the upper bout side edges. On the contrary: the top is pushed down and
stressed. Additionally the neck pushes against the sound hole. The top grain is stressed since it is uncompressed
crossgrain and pushed down and forward in grain direction. The top grain has to retreat. Big troubles are
knocking at the door. If the top still is not able to follow these big forces and deformations it will start to crack
as shown. Most common are fret board side cracks and upper bout cracks.
Now the back shows little but strange deformations. While the waist ist pulled inward the back at this place is
pulled outward as consequence. Additionally the first flat (or 3rd) back brace is pushed inbound and the top
flattens at this place. But what happens to the first back brace? It seems that while the sides at the upper bout
kink and are pushed outward the first back brace will be pushed inward. Additionally the neck block rotates and
wants to push the back flat; so it adds to this force. This is John's understanding as far as I see. But at the other
side an arch resits better against any deformation and also there is a force outward at the first back brace since
the neck block rotates. So possibly not to figure out exactly this way.
Author
Comment
Now since this all is of big interest to understand what might happen at an old Martin, we want to understand
what this might mean concerning our question about arches. An arched top reacts on top compression very
different. The main parts again are around the sound hole - just above at the fret board tongue brace and
below at the center and at the upper parts of the X. The places are pressed down as well (as the non-arched
top) but now against the arch.
Author
Comment
If both places are curved and are raised above the side level the forces and reactions are directed the other
way. This means the forces push together and compress rather than uncompress and pull apart. Now here's the
direct comparison between the non-arched and the arched top, same forces in the beginning: While the flat top
is uncompressed crossgrain and tends to crack and the side edges are pulled inward, the arched top still only is
compressed (what sounds better) and won't crack.
The side edges might be pressed outward but since still the entire complex (upper bout construction) is
compressed the sides won't retreat and deform since there's now way to do.
Author
Comment
Now it is my understanding that the area underneath the fret board tongue including the fret board tongue
brace is the most important part. As far it is arched the possibility of a twisted and deformed body is minimal.
As soon as there is no arch left and the forces start to uncompress and to pull apart caused through the
pressure downward above and below the sound hole the troubles will start.
Now this are theoretical thoughts but I guess after doing real guitar construction and repairs for a while there
might be some truth in it. At least worth enough to look more seriously at top and back arches.
Willi
Author
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FoolForWood
#136
[-]
You know folks, this man actually asked ME in earlier threads if I had a day time job and if I ever slept.
And this is not the only thread he's doing great things on! I won't even go into things like a busy job, family life
etc. etc.; the things most of us are also busy with. Is there an award for the most constructive UMGF-er? Don't
do nominations first, give it to the man NOW. And cast it in gold! I know he hates it when I do this, but I just
can't help myself.
(02/24/07 2:30
PM)
I'll get back on the actual contents of his post, soon.
Oh, and thanks Willi. I know you promised to make a little sketch. But this exceeds all my expectations.
Henk
#137
[-]
Willi,
I'm really amazed no one responded to your sketches yet. I deliberately waited a little while to give others a
chance, because this thread shouldn't end in a Willi and Henk dialogue.
But OK then, I'll play the journalist or interviewer, like I did in some other threads. After all your great posts, I
don't know if I can be objective enough, but I'll try.
FoolForWood
Choices in the way of building, like making stronger or different arches, will have a several consequences.
1. It will somehow affect the sound.
2. It will change the structural coherence.
3. It will cause a (minor) change in the appearance of the instrument, if you look for it.
Let's forget about number 3. Number 2 we will do in detail anyway. So let's do number 1 first.
Quote:
(02/27/07 1:00
PM)
it simply sounds better
Some critics will say that that is in the ear of the "beholder". But could you try to explain the differences in
tone? Also, what will it do to the Martin tone. If you are so impressed and inspired by a certain prewar model
that you want to build a replica, down to the last cosmetic detail, how closely do you want to approach the
original tone? If taken to the extreme, isnt there a chance you'll end up with a Larsson guitar in Martin clothes?
And if capturing the "true" vintage Martin tone would mean building the guitar structurally a little less sound
than you have the ability to do (even without adding mass), would you consider to take the stucturally slightly
less perfect route to get that tone?
Author
Comment
Yes, it's still me, Willi. Just trying to get some debate going here. Seriously though, I do think everything one
tries to do to prevent structural distortion, no matter how light and no matter how clever, must have an
influence on tone. That is because the moment you pluck a string you structurally distort the guitar too, albeit
for a short moment. So IMO, preventing long term distortion will always prevent something to happen in the
very short term plucked note as well. Particularly in the attack of note (immediately after you let go of the
string, and the guitar gets the chance to fold back again) and possibly also in the release phase.
Let's look at the two hinging points in a guitar. (This is my understanding BTW; maybe scientifically not totally
correct). One hinging point is at the bridge (saddle). Everything you change here, from moving braces to
stiffening bridge plates or increasing top arching, whatever, must change the tone, particularly the attack. The
other hinging point one might expect at the nut, but I believe, especially if the neck is stiff enough, that most of
the hinging is displaced to the neck joint. My OM-18GE is such an animal with a very fat and stiff neck, despite
the fact it has 14 frets to the body. It also has very thin sides. They are 1.7 mm thick, which I consider thin for a
light and porous wood like mahogany. The moment I firmly play the low E string, before letting go I literally feel
the guitar folding in. Exactly the thing we don't want it to do permanently. When, a fraction of a second later,
the pick loses contact it feels like an arrow is shot from a bow. An impressing punch is the result. Also, that
characteristic Martin bark is heard. Suppose the sides were left thicker, like the drum rim approach of some
modern builders. In that case the hinging movement at the heel would be less. Suppose you also stiffen up the
bridge area (remember the guitar has 1/4", scalloped, forward bracing) let's say by arching more. That will
decrease the hinging movement at the bridge (and at the fretboard side). The guitar will now be stronger and
will resist structural distortion better. But would it still sound anything like my guitar? Will the punch and the
bark and the growl still be there?
And how much is that second hinging point (at the heel) worth? Luthier Rick Turner builds two graphite beams
in his guitars that run from the top of the heelblock to the back linings of the (stiff) sides (at the narrowest part
of the waist). He is only interested in the bridge side, as far as tone is concerned. It seems a good idea for
several reasons, but somehow it also reminds me of a bow with one side disabled. I wouldn't want to shoot
arrows with such a weapon.
Henk
BHguitars
(02/28/07 4:07
AM)
#138
[-]
Henk,
seems we already have a dialog. My intention at this thread to bring in construction ideas that indeed are
featured at the guitars we build at one side but at the other it is hopefully clear that we didn't invent these
features. So it's not my intention to explain our way of guitar building, I try to explain some traditional aspects
of it and why it does make sense.
- what way have old guitars been constructed and built?
- what can we learn today and especially to what features should we look?
So I totally disagree to use the term "the Martin" tone that might be characterized by people depending on
1970s and later Martins in a way meaning if a guitar does sound like a 70s Martin it sounds like a genuine
Author
Comment
Martin. I even wouldn't like to talk about a pre war Martin tone. But this would hit the core better. Most of all
I'd say I like the tone and quality we all appreciate at pre war guitar in general not depending on the label. But
of course there are differences amoung them. Since I like several makers and models there might be several
ways to reach the goal. So it makes such a big difference to me if I try to treat old wood the way it has been
done these days and to use genuine techniques and materials like hide glue and nitro lacquer as far as I'm
aware of and as far I understand about. A close look to modern construction details tell at once about the
quality of "Martin" tone. If a modern Japanese designed U style adjustable truss rod is used the neck the neck
tension is gone in most cases for my understanding. If white glue is used at the entire guitar the sound quality is
lowered noticable. Not talking about many other details and features. It might depend on the own person how
to judge about construction and "Martin" tone. One aspect might be how serious the maker is in reaching his
goal and what it might look like.
The main question here is how to handle arches or the question wether to use arches at all. I tried to figure out
how Martin used to handle arches in the old days for my understanding but also there are other makers that
treated their guitar in an other and well appreciated way. So why not looking over the rim? Now decades later
after declining years in traditional acoustic guitar construction till lets say 20 years ago guitar makers currently
have shown interest (more or less) in old and forgotten techniques and ask about their attributes and qualities.
So it may not be the same question to discuss arches at all rather than to ask about how the arch (as part of the
entire construction) is created. I think I have shown surprising similarities between Gibson top construction and
Martin top construction although both differ obviously if somebody is looking only at the surface.
Now when Rudie and me are going to "reconstruct" a prewar model we try to hit the core and not the
cosmetics. Of course it may differ what way arches are created if preferred at all but I want to add that my
point of view is to compare directly a 1936 Gibson AJ to a 1936 Martin D-28 and try to learn. Many people
believe that the AJ simply is the better construction soundwise and has more of the "Martin" D-tone than some
Martins. So we are free to learn from other makers and constructions. BTW, the basics of the top arch Rudie
and me prefer at our guitars are taken from Gibsons not from Larsons. The Larson guitars are a quality and feel
by their own (that still haven't been revived seriously by any other maker to my knowlegde) and their
inventions could mean something like "the hand book of steel string guitar construction" to me but won't mean
that the Martin or Gibson roots are less in comparison. But it makes much sense to think about the Larson
characteristics and features.
There's another major aspect in guitar construction: it is not like single features added together make a unit or a
philosophy, it's the entire thing that works or works better or less. So it may not be the question if you want to
use a steel T-bar in your neck to recreate a prewar Martin neck - the old style one-piece rolled T steel profile
featuring the essential hard and stiff skin and surface tension is not available any more and anywhere - it is the
question if you are building a modern factory guitar or if you try to build in the old way. As I said before, there
might be several ways to reach the goal and also there might be different goals in the end, but the entire guitar
has to work as all features create a network that builds the whole issue.
So to find out what construction details and what each feature will gain, what influence it might have and how
all together sum up has to be found out in the practise. So theoretical conclusions only help till a special point.
Behind this point one has to find out by doing.
I agree to you that of course every single feature leads to any consequence. But in the case of your guitar I
would remove the truss rod and replace the frets (and theoretically all the white glue and all the plastic primer
Author
Comment
at your OM) in the first place before it would make sense for me to discuss anything further on.
BTW, I wouldn't be happy with a guitar looking like at a D-18 and sounding like a Larson. But a D-18 that has the
fine tone of D-18 and the power and volume of a D-28 is much fun
Willi
#139
[-]
Quote:
I'm really amazed no one responded to your sketches yet. I deliberately waited a little while to give others a
chance, because this thread shouldn't end in a Willi and Henk dialogue.
Steve Frost
I'm thinking there must be a number of others like me, who are following the thread with great interest, but
don't necessarily have a lot to add at this point. There's a LOT of information to digest here. In some cases I
hadn't thought about these issues in quite this way, and doubtless there are things that I hadn't thought about
at all! So, I'm involved in the process of revamping my whole approach to building guitars. Next thing I know, I'll
convert to using hide glue!
(02/28/07 11:10 I'm sure others will chime in, as soon as they finish reading the riveting "How old are these strings?" thread!
AM)
Quote:
I agree to you that of course every single feature leads to any consequence. But in the case of your guitar I
would remove the truss rod and replace the frets (and theoretically all the white glue and all the plastic primer
at your OM) in the first place before it would make sense for me to discuss anything further on.
What do you say, Henk? Are you ready to open her up as a learning experience?
Arnoldgtr
#140
[-]
Quote:
What do you say, Henk? Are you ready to open her up as a learning experience?
(02/28/07 12:36
PM)
Henk is probably waiting for me to finish mine. So far, I have removed the neck, the fingerboard, the truss rod,
the popsicle brace, the #1 cross brace, the neck block extension, and the bridgeplate. Based on recent
Author
Comment
experiences, I will probably remove the bridge for a reglue with hide glue, too.
I plan to use an ebony bar in the neck.
I guess the hardest decision left is whether to go full-bore with bar frets, or just do a compression refret with
tee frets.
John
#141
[-]
Quote:
Henk is probably waiting for me to finish mine.
John,
You beat me to it again. I'm very curious what the result will be.
FoolForWood BTW, do you have any comments on Willi's drawings?
Oh, and how thick was the fretboard on an original 1930 OM?
Steve,
Quote:
(02/28/07 4:01
PM)
Next thing I know, I'll convert to using hide glue!
Huh, you mean there are other glues?
Willi,
Since this thread was getting a little one sided (as to persons contributing), I thought I'd stir it up a bit. Since you
were the only one left, you were the "victim". But you sailed through perfectly, and we seem to have woken up
a couple of folks again. Thanks for your reply. But before we go to number 2 (structural coherence), one
question remained unanswered, I think. Could you describe (in your own words of course) the difference in
sound between a totally flat top, or a slightly arched one? (All other things being equal). The sheer title of this
thread makes this an important question.
Henk
Author
Comment
#142
[-]
BHguitars
Henk,
this thread only takes a rest. The arch thing still is not complete. And already not discussed yet. I may come
back to your further questions but spring is saying hello and we have to speed up with the bodies. Anyway, I'm
surprised also a little that there were no questions on the "body compression" theories since nearly every old
Martin is concerned more or less.
(03/06/07 5:58
PM)
To be continued.
Willi
#143
[-]
FoolForWood
Willi,
I did want to go into your drawings this week (part two; the actual structural bit), but if it suits you better I'll
wait awhile.
Success with the bodies, and be careful with your own.
(03/06/07 7:05
PM)
Henk
BHguitars
#144
[-]
This is to continue and to complete the arched top/back thread started a while ago. We have reached the point
of construction so far that the rims were bent and received their final level. Still the top and back need to be
braced, the lining to be added to the sides and the plates to be glued on. Here we go.
(06/15/07 6:33
AM)
Glueing the braces to the back in full height with hide glue (no other glue for sure and never). The mold also has
a slight longitudinal arch caused by the pressure over the years through the spreading sticks.
Author
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Author
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Stored after bracing near the room heater to keep the plates dry and in the same humidity:
Author
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Now the carved braces - the back is prepared to be glued onto the rims. The overstands at the sides and brace
ends make it easier to place the back right to the center. The inside edges of the braces are fitted into the lining
pockets but they don't hit against the sides. In the case the back moves because of lower (or higher) humidity
anytime later the brace ends won't press against the sides (and cause bumbs or in the worst case opened glue
joints).
Author
Comment
The lining surface is corresponding to the back arch (and to the top arch at the other side of the rims in the
same way). The end and neck block also feature a corresponding shape. The pockets at the lining are cut and
fitted exactly to the brace ends.
Author
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The body inside is spreaded very solid to prevent that the pressure added during the glueing operation of the
back can press the rims at the blocks and at the waist against the body inside and cause a complete
deformation of the body. The spreads are left inside the rims and the rims inside the mold until both, back and
top will be glued on. Then they will be unscrewed and removed through the sound hole.
The back shows a nice longitudinal arch as well only through the treatment described before. This mean less
stress to the back when it is glued to the rims.
Author
Comment
The press. I guess it once was a juice extracting press. It is a main tool that enables us to get perfect glue joints
for top and back, best pressure control and best of all: we can speed up really fast for the (hide glue) gluing
operation. Although this press really looks very solid (it is indeed and very heavy as well) we use only very light
pressure since only light pressur is needed and welcome.
The shape fits to the top and back arch. The rubber lining only is placed around the body edges at the glue
joints to prevent that top or back will be receive any pressure during the gluing operation.
Author
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Comment
The back and the spreaded rims after this operation.
The braced top (gluing operation shown above) with carved braces. Note the different brace ends. All braces
are tucked into the X braces. The ends of the main braces are tucked into the linings, especially at the upper
bout. The finger and tone bar ends are carved smooth to the top surface (still some hairline thick grain left).
Especially the tone bar gain through this detail in sound and structur also.
Author
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Again the press:
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The completed body with already levelled rims. Here are some views towards the back arch:
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Now the top arch. I just took the pics. The plates are glued on a while ago and meanwhile it is rather high
humidity here, it is raining and the plates especially the top have a stronger arch now. The body won't receive
any further operation in this condition. I will continue in late summer or fall when the humidity will be lower
and the arch will be less. But besides this it's not a mistake if the body is resting a while before the borders and
bindings are added. Meanwhile I have lots of work with the necks.
Looking at the top arch there is the arch at the lower bout in both directions:
Author
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Author
Comment
The arch of the upper bout is very important as well. It prevents that the body would be pressed in (as
explained above) and also it gains a perfect surface/level for the fretboard extension meaning for the correct
neck angle. A nice levelled fret board extension at the upper bout must rise a little against the sound hole.
Author
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The view from the side. The waists are not rised so much, just a little to gain a nice all over top arch from the
neck to the end block. Now the top area between sound hole and bridge position is the highest point of the
arch. Later, under string tension, this place will be pressed in a little what will gain the uniform and pronounced
top arch this construction is done for (I hope so).
Author
Comment
The reasons now why we use these arches are multiple as discussed before. But besides a solid and remaining
construction we want to gain a more powerful sound and better attack or in other words we believe that
guitars with such arched plates including Gibsons, Larsons and those Martins featuring a similar top arch are the
best sounding guitars at all.
Author
Comment
Willi
#145
[-]
Thanks for reviving this thread, Willi. I had hoped you would, as it's one of my favorites.
FoolForWood
(06/15/07 8:03
AM)
The same funny thing happened as when I opened the adi thread here awhile ago. All posts were in random
order at first, and now it's all fine again. Strange. BTW, this thread was duplicated when The Log Cabin first
started. It used to be in The Vintage Corner and the first 143 posts are now reasonably safe in volume IV of TVC
archive. I'm not sure if this is a real wood thread, but it's good we can continue it here. What we don't know
however is:
1. Will The Log Cabin be here to stay? It's been here less than three months and there would be a trial period.
2. If The Log Cabin has been successful enough to stay (I would say so, but I'm not the one to decide), will it get
its own archive?
Anyway, we're back on track. Perhaps Bruce can add some things now, too.
Henk
BHguitars
#146
[-]
Thanks for the comment, Henk. I was also wondering a little if this thread is at the right place here but I don't
mind where it could be found (I don't find them usually anyway).
Quote:
Perhaps Bruce can add some things now, too.
(06/15/07 8:10
AM)
I'd like to hear.
Willi
Michael Segui Re: "Flat tops" vs arched bracing
WOW. A lot of info to digest here!
This is great considering I am in the process of building my first acoustic.
Thanks!
(06/15/07 12:42
PM)
Michael Segui
#147
[-]
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Est. 1974
"I too was once penniless."
Steve Frost
#148
[-]
Dang! There's a whole lot of things to digest in this thread, and specifically in this last section. This is too
important to languish on page 2 or beyond. Willi, thanks for your amazingly detailed posts! It's a real education!
(06/26/07 10:04
PM)
#149
[-]
Quote:
BTW, does John or Willi know, from old factory pics maybe, whether the sides were profiled before the
bending, like most builders like to do nowadays?
Arnoldgtr
I have unbent profiled BR sides from the 1960's, and I have no reason to doubt that Martin used them much
earlier than that.
Quote:
John,
You beat me to it again. I'm very curious what the result will be.
(06/26/07 11:10
PM)
Unfortunately, the OM-18GE project is on the back burner currently. I have a couple of 'real OM's' that need a
lot of attention.
Quote:
My 1930 OM-28 measures 0.208" in the center of the fingerboard at the nut, and 0.190" at the soundhole end.
The 1931 OM-18 is approximately 0.005" thicker.
Author
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Quote:
BTW, do you have any comments on Willi's drawings?
Perfect illustrations of the stresses involved.
After seeing Willi's body construction photos, I shouldn't be too surprised at how similar our building methods
are. My forms are ladder construction to save weight, but the function of them is the same. I use spring-loaded
'go bars' to clamp the braces rather than the bent type.
I also use two screw type spreaders from neck block to tail block and across the waist.
With the spreaders installed, the form is rigid enough to do the final side profiling with a block plane and
sanding blocks.
I prefer to install the top first, since it facilitates easy installation of the wedged plate under the fingerboard.
Regarding Martin arched bracing, I recently learned that Martin currently uses a 52 foot radius on their top
braces.
John
#150
[-]
John, what a surprise! This thread went to sleep for awhile, but there will still some questions left unanswered.
You found them and answered them, too. That's great! Much appreciated.
Quote:
FoolForWood
My 1930 OM-28 measures 0.208" in the center of the fingerboard at the nut, and 0.190" at the soundhole end.
The 1931 OM-18 is approximately 0.005" thicker.
That's what I thought; thinner than on modern Martins. For the OM-18GE I understand they put some effort in
copying an original 1930 neck. But do you think they've taken into account the fact that the boards are thicker
now. And will you thin yours down?
(06/27/07 10:06
Quote:
AM)
I have unbent profiled BR sides from the 1960's, and I have no reason to doubt that Martin used them much
earlier than that.
Were they profiled for the back only or also for the top?
Quote:
Author
Comment
Regarding Martin arched bracing, I recently learned that Martin currently uses a 52 foot radius on their top
braces.
That's a very subtle arch; you don't really need to pre-profile the sides in that case. Perhaps no profiling at all
for the top side? And is that 52 ft radius also used for the upper transverse brace or could that one be a little
rounder to accommodate to the back angle of the neck?
I still have one burning question about Willi's drawings, but that's
a different matter, so I'll save that one for the time being.
Henk
#151
[-]
Here's a question from John Platko that never got answered:
Steve Frost
Quote:
it?
(06/27/07 11:30
AM)
It would seem that somebody must know the answer to this. My wife's 1970 000-18 doesn't appear to have
been dished. I first heard of the dish in an LMI catalog in the early/mid eighties.
I'm asking partly because I'm wondering whether this 000 would be a good example of traditional Martin side
profile and back construction-or not?
#152
Arnoldgtr
Quote:
Were they profiled for the back only or also for the top?
(06/27/07 11:57
Only the back. The top edge is straight.
AM)
On the GE project, I may just replace the fingerboard if I go to bar frets. The dots are wrong for a real OM
anyway (too colorful).
[-]
Author
Comment
Quote:
it?
I am fairly certain that this occurred in the early-1990's, when the A-frame braced guitars came out.
Quote:
I'm wondering whether this 000 would be a good example of traditional Martin side profile and back
construction-or not?
A 1970 000-18 would be profiled the same as a 1930's Martin.
John
#153
[-]
Quote:
BHguitars
Henk,
fretboards may have been thinner in average at original OMs but they varied also. I have noticed thinner and
thicker boards. In average they may have been between 5,5mm ~ 0.2165" and 6,0mm ~ 0.2365" at the thickest
point (mostly near the 14th fret). At the nut the boards usually are a little thinner because of levelling and the
curving operation before they had been fretted.
(06/28/07 4:48
AM)
This is what I have on hand:
1931 OM board (removed, possibly already sanded slightly):
nut: 5,36 mm ~ 0.211"
14th fret: 5,95 mm ~ 0.234
1934 long scale 000:
nut: 5,67 mm ~ 0.2235"
Willi
Author
FoolForWood
Comment
#154
[-]
Thanks, Willi. If the board is thinner at the nut, it will add to the back angle of the neck. Also, on a cylindrically
arched board (one radius) with a constant thickness in the middle, the sides will get less tall as the board gets
wider. If you want to have more or less the same "height" or thickness at the sides, the board at the centerline
must be made thinner towards the nut. (Or you'd have to make a compound radius, conically arched board.)
These might be two reasons why they did what they did. What do you think?
(06/28/07 6:18
AM)
Henk
BHguitars
#155
[-]
Quote:
If you want to have more or less the same "height" or thickness at the sides, the board at the centerline must
be made thinner towards the nut.
(06/28/07 8:11
AM)
This is the case I guess. The fretboard curve is the same up and down the board and the visible height of the
fretboard edge as well more or less. This means slightly tapered thickness of the entire board.
Willi
Steve Frost
#156
[-]
What height would you recommend for the low and wide braces for a 000 size guitar? My Stew Mac plan shows
about .420 inches, and I'm just curious if that's in the right ballpark. That appears to be about what my wife's
000 has. I've gotten some bad information in the past, so I figured I'd ask before I engage in some "semi-skilled
hand tuning" on some braces.
(07/07/07 8:05
AM)
FoolForWood
#157
Steve, is that the 12-fret plan? I have it, too, and would very much like to know how it differs from Willi's
blueprints or John's archived measurements. In other words: good question!
(07/07/07 8:52
AM)
Henk
[-]
Author
Steve Frost
Comment
#158
[-]
Henk- yes, that's the MacRostie 12 fret plan. The back braces all seem to have a 15 feet radius, which is one
thing that made me wonder about its "vintage authenticity".
(07/07/07 9:50
AM)
FoolForWood
#159
[-]
#160
[-]
Have you been in The Lounge lately?
Henk
(07/07/07 10:40
AM)
Steve, when you said "low and wide", somehow I didn't grasp you meant the back braces. I've checked my
notes and found the figures. I believe we have to thank John for these.
Upper back braces width x height.
FoolForWood
Trad. Martin dreadnought: 5/16" x 5/8".
Modern Martin dreadnought: 5/16" x 5/8".
Trad. Martin 000: 17/64" x 1/2".
Trad. Martin 00: 1/4" x 1/2".
Lower back braces width x height.
(07/10/07 2:10
PM)
Trad. Martin dreadnought: 3/4" x 3/8 to 13/32".
Modern Martin dreadnought: 3/8" x 3/4" (on other sizes also).
Trad. Martin 000: 3/4" x 5/16 to 11/32".
Trad. Martin 00: 3/4" x 5/16".
So they're lower than on the StewMac plan.
Henk
Author
Steve Frost
(11/07/07 6:48
PM)
FoolForWood
Comment
#161
[-]
Well, we're back in the waning autumn, with the temperature and relative humidity dropping like a stone, the
season when a young....err, middled-aged man's thoughts turn to.... bracing! Henk had some burning questions,
and Willi and John probably have some further thoughts, if properly motivated. Where's that Motivator we
hired?
I've probably learned more about guitars in this thread than in any other, and I'm immensely grateful. And all
without any acrimony or sophomoric chatter. Thanks to all!
#162
[-]
#163
[-]
You're not thinking this thread has had it, are you? You ain't seen nothing yet.
Henk
(11/07/07 7:12
PM)
Wow. How did I miss this thread? Thanks to all for sharing such a wealth of knowlegde. Due in large part to this
kind of participation I've recently embarked upon my first effort at building a guitar. I'm having a tremendous
amount of fun and find the process surprisingly calming and therapuetic as well.
Anyway, Willi, way back on page one you wrote moocatdog
Quote:
...the main braces will be tucked or mortised into the kerfing with an exact cutout for the braces. The back of
the kerfing could be left with its glue surface to the sides. This way the brace ends are locked in and won't get
loose. The brace ends shouldn't hit against the sides directly since when the arch will move down a little
because caused by low humidity you wouldn't want to find the braces to be pressed against the sides.
(11/08/07 1:14
PM)
I am currently at this very stage in my build and want to make sure I understand what you are saying. I am clear
on tucking the main braces into exact cutouts in the kerfing and I can see why you want to keep the brace ends
away from the sides. But I can't visualize what you mean by "The back of the kerfing could be left with its glue
surface to the sides."
If you (or anyone else) have the time to elaborate on this or provide some sort of photo or diagram, it would be
greatly appreciated.
Author
Comment
Moo :-)
$800 billion and counting. Hey, it's your money.
BHguitars
#164
[-]
#165
[-]
Are we back to discuss arches again?
Willi
(11/08/07 1:48
PM)
Quote:
John Platko
The back of the kerfing could be left with its glue surface to the sides."
I think this means that the notch cut in the kerfing to receive the brace ends does not have to extend all the
way through the kerfing to the sides of the guitar.
(11/08/07 2:01
PM)
So looking at a cross section of this area of the guitar you would have sides, a little bit of kerfing, air, and then
the end of the brace.
moocatdog
[-]
John,
Thanks for your reply. The several sources I've referenced all recommed that the cutouts for the X-braces and
shoulder braces should be notched all the way through the kerfing and the sides, so that the brace is basically
resting atop those surfaces. I thought everyone did it this way. Like I said above, this is so much fun. I'm having
a blast learning about the various techniques people employ. I think I may be a wood and glue addict.
Moo :-)
(11/08/07 2:37
PM)
#166
$800 billion and counting. Hey, it's your money.
Author
John Platko
Comment
#167
[-]
Willi's description of how to mortise the brace was news to me. I was taught to bring the braces all the way to
the sides with no air gap. In fact the braces were used to help push the sides to the right place. I was also taught
the method of cutting all the way through the sides but that was mostly as an easier way to help the beginner.
I see Willi's point though.
(11/08/07 4:29
PM)
#168
[-]
Quote:
But I can't visualize what you mean by "The back of the kerfing could be left with its glue surface to the sides."
Quote:
So looking at a cross section of this area of the guitar you would have sides, a little bit of kerfing, air, and then
the end of the brace.
BHguitars
This is exactly what I mean. Well described, John.
(11/08/07 5:40
PM)
Moo,
There are basically two possibilities to create a snuggly fit of the brace ends:
- either to the back of the kerfing (meaning the lining still is existant while the kerfed or notched parts are cut
off for the mortise) or to the sides in the case the kerfed lining is removed completely for the mortise.
- or the kerfed lining and sides are slotted completely as you and John mention what means the brace extends
to the side outside and will be routed off later for the binding.
Now all this means in the case the back might move that the braces will cause in most cases a bump either to
the sides or to the binding depending on what place exactly the brace end might hit against. This is valid for the
top and the top braces also especially for the main brace under the fret board extension but not so much for
the X braces.
I have also seen even some pre war Martins with such bumps caused by back braces hitting against the side but
not very often.
Willi
Author
Arnoldgtr
Comment
#169
[-]
I don't notch all the way through the sides, but it is for a simpler reason than Willi has indicated. My brace ends
(particularly the #1 cross brace and the upper end of the X-braces) are too tall to be completely covered by the
binding size I use. I like the shorter binding as used on the prewar Martins (~ 0.170" on dreadnoughts).
I have seen a few prewar D-18's and 000-18's with bumps in the sides at the ends of the back braces, so the
idea of leaving a small space has some merit. But I never do it on the top braces.
(11/08/07 6:13
PM)
moocatdog
John
#170
[-]
Thanks to everyone for the informative replies. I really appreciate your willingness to share your knowledge and
experience.
(11/08/07 11:43
PM)
#171
[-]
This old thread is a great one, folks. And it's still alive. Don't know why it ended up in the Cabin, but that's OK;
it's in good hands here.
Luthiers who joined us later, or returned from a break, might still want to read this one. But you don't have to
be a luthier to enjoy this stuff, of course. If you think it's too much to read it all, in any case read Willi's
contributions with the pictures and explanations. Great stuff. And John's posts, as always, are too. And if it's a
FoolForWood
rainy Sunday with not much to do, just read it all.
I'll add a new question.
Willi made some drawings to show how a guitar will distort and fold in over time, because of the string tension.
They are on page 7. Arching of the plates play a part in that discussion. But how about the guitar's shape? Let's
compare the wide-waisted, almost rectangle shape of a dreadnought to that of the narrow-waisted "small"
jumbo. I remember this coming up once, before I was a UMGF member. One of the luthiers who were posting
(01/06/08 10:10 at that time argued that a dread is stiffer. To prove his point he said that if you try to flex a dread soundboard
AM)
(already roughly shaped, but not yet glued to the body) lengthwise, it is stiffer than a small jumbo top. Well,
that figures because where there's wood in the dread's waist, there's only air in the small jumbo's waist. But
since that thread was about sinking in of the top in front of the bridge, I believe the analogy was flawed. Once
the tops are glued to the body, the narrower waist in the small jumbo should resist sinking in better. The (now
supported) plate is narrower in that area and hence stiffer. No?
However, when it comes to the folding in of the WHOLE instrument, I'm not so sure. It would seem that a
rectangle box resists folding in better than, let's say, an hourglass-shaped one.
Author
Comment
Anyone?
Henk
0021fan
(01/06/08 7:56
PM)
Tonyfrancis M
#172
[-]
Just finished reading this wonderful thread. Doing so prompted the sharing of these bracing photos for
commentary by the experts regarding the construction techniques being used here .. particularly what appears
(to my uninitiated eye) to be a laminated bracing design. These are pics from a luthier who makes flat-tops
based extensively on Larson construction techniques (Larsons incorporated slightly but visibly arched tops and
backs). Based on what is shown here, I'm curious to hear perspectives as to what this construction and bracing
is designed to accomplish. I'll apologize in advance for being unable to offer futher information since I'm way
out of my league here. I'll just post these and await replies ...
#173
[-]
This is an exceptional thread by all accounts. Many thanks for the info shared by all and to those who have
bought it back to life!
(01/06/08 10:14 Back to arches again
PM)
#174
[-]
Hello,
Larson70
I am new to this site. But I actually replied earlier today to a separate thread about Montuoro Guitars. Looks like
those are pictures from his website. Its really unique stuff. When viewing those instruments amazing the
amount of radius that is built into the top. The top and back look similar. It is so different than Martin style
guitars. A Martin is almost like a box compared to a Larson. And that of course is a huge factor in the individual
sounds.
Oddly enough its not a very familiar tonal quality to most people. The Martin sound is really what so many
people are accustomed to hearing. As much I love old Martins, once you get hooked on that Larson sound its
(01/06/08 11:51
almost hard to go back. It sounds as if the guitars are amplified. That is a bi-product of building that way.
PM)
When I was at Montuoro's shop he demonstrated this for me. Resting the soundboard on a flat surface it would
just spin on this small center index. Almost like a football shape. You should contact him with questions if you
have them. He was real nice and down to earth person. Its just very interesting that he understands that
building style so well.
Author
Comment
#175
[-]
Welcome Larson70 to this forum. The Larson guitars receive a great acknowledgement in the recent past and
that's nothing else than deserved. Their inventions are the same level or even more important than those
coming from Martin and Gibson. There are some very interesting construction features and details that create
their characteristic sound such as the pronounced top arch and the laminated top braces as we know. These
designs were almost burried and the guitars almost unknown for decades. One of the first people recognizing
their quality and value was George Gruhn in the late '70s (not a private collector from CA a few years ago).
Some people and musicians before George including Bob Dylan.
BHguitars
While the top arch is an important characteristic feature at all Larsons this feature is present at the post mid
'30s Gibsons not minor and before this it was noticeable at other single guitars as well. So the idea to arch the
top actually was present around this time similar as the X-brace was around in the 1840s as CF Martin
intruduced this bracing pattern at his guitars.
(01/07/08 3:58
PM)
While I appreciate all the Larson inventions and construction features there are several independent makers
recreating the Larson style and construction starting many years ago. And I want to add that most of the tribute
for reviving the Larson creations has to go to Bob Hartman who did a great work in researching the guitars of
his grandpa and granduncle.
I've looked at Frankie Montuoro's site and the guitars look very nice and interesting. It seems he just started
with his Larson project being impressed by the Larson inventions and, as some other fellows, seriously trying to
rediscover their designs and constructions.
Below is our interpretaition of a Larson style laminated top bracing pattern for a 16 3/4" Jumbo guitar in the
Euphonon/Prairie State style. In difference to the Montuoro bracing we prefer to use the laminated braces only
for the main braces as we have seen at original Larsons. Characteristic is the position of the second tone bar
that is not parallel to the first one. Different also is the fan angled finger bracing which is common at Larsons
and present at Montuoro's bracing while we prefer the traditional style being parallel to the upper X-leg.
Author
Comment
Willi
Author
Comment
Larson70
#176
[-]
I actually own an original Larson that has all of the top braces laminated. Its rare for sure. Also both transverse
braces under the fingerboard extension are identical in shape and laminated. More like the Montuoro pictured
not the 16-1/2". Although it looks mighty fine
The guitar I own was previously restored by Montuoro. So I assume maybe he took that idea of all braces being
laminated from that guitar. I own some rare Larsons and one thing is for sure. They are consistently inconsistent
with many of their design aspects.
The Montuoro I played at his shop was really amazing sounding! It had all those Larson characteristics going on.
(01/07/08 10:11 Minus all the crude inlay work etc. Sorry Carl and August no offense. But he has seemed to nail the concept for
PM)
sure.
Are you making Larson style guitars as well?
#177
[-]
#178
[-]
Quote:
FoolForWood
Are you making Larson style guitars as well?
www.antique-acoustics.de/de/katalog.htm
(01/08/08 5:14
AM)
No not me; Willi and Rudie.
Henk
BHguitars
Several models and styles at the site Henk linked to above.
Some samples:
(01/08/08 8:07
AM)
Author
Comment
Author
Comment
Author
Comment
I'd be very interested to see a pic of your unique Larson if you would want to post. As you say the Larsons didn't
hesitate to create new features and unique guitars I didn't see any Larson with completely laminated bracing. I
have seen various style of bracing including maple top bracing but not such a pattern you describe. Would be
interesting to learn more about it.
Willi
Author
John Platko
Comment
#179
[-]
#180
[-]
What kind of wood did they use for the brace lamination?
(01/08/08 1:48
PM)
Quote:
BHguitars
What kind of wood did they use for the brace lamination?
John,
Not an easy task to find out even if you remove a brace to take a closer look or scrape a little and smell. I'm not
aware of any serious determination - Bob Hartman calls it when I recall right "dark hard wood".
(01/08/08 3:53
PM)
My opinion and understanding is that it is BRW (between spruce). The color and appearance is right and it
makes much sense since one can use the fall-down of the sides in the most cases or faulty pieces. So there
actually is no additional cost or labor.
Willi
Tonyfrancis M What did Larson Bros use for neck reinforcment? Ebony rod?
Amazing guiatars Willi...
(01/08/08 6:36
PM)
#181
[-]
Author
martintones
Comment
#182
[-]
#183
[-]
You guys amaze me. Wonderful thread.
(01/08/08 6:41
PM)
Quote:
John Platko
John,
Not an easy task to find out even if you remove a brace to take a closer look or scrape a little and smell. I'm not
aware of any serious determination - Bob Hartman calls it when I recall right "dark hard wood".
My opinion and understanding is that it is BRW (between spruce). The color and appearance is right and it
makes much sense since one can use the fall-down of the sides in the most cases or faulty pieces. So there
actually is no additional cost or labor.
(01/08/08 8:44
PM)
Willi
Thanks Willi.
Any idea why they did this?
Larson70
#184
[-]
Re: Larson's use of Neck reinforcement material.
Generally they used Maple throughout most of the line. The real cheap guitars had no reinforcement at all. In
the mid to late 30's they did use steel rods on the Euphonon line as neck reinforcement.
I would also like to point out that even with all their patents and experimental building practices they still never
utilized adjustable truss rods. This was no accident Its for a reason......
(01/08/08 9:42
PM)
Author
Larson70
Comment
#185
[-]
One can only assume that they were just smart woodworkers. Any time you laminate anything it becomes much
stronger. Often without having to add any additional structural weight.
(01/08/08 9:54
PM)
And being that their concept was strong / powerful guitars it falls right in line with that idea.
#186
[-]
Quote:
John Platko
Any time you laminate anything it becomes much stronger. Often without having to add any additional
structural weight.
Well it does depend on what materials you laminate with.
In this case, since the BR has a higher Youngs Modulus than spruce, a brace of the same size would be stiffer
and of course weigh more. But it would also weigh more than a taller all spruce brace that had the same
(01/09/08 12:16
stiffness.
AM)
This is curious because usually modern builders are trying to keep the weight of the top down.
Maybe they wanted to increase the stiffness for structural reasons but didn't want to increase the frequency of
the modes. The added weight would help to keep the modes down as the added stiffness raised them.
Or maybe they just wanted something that sounded different than a Martin.
BHguitars
#187
[-]
Quote:
What did Larson Bros use for neck reinforcment? Ebony rod?
(01/09/08 4:17
AM)
Tony,
I have seen several neck styles at Larsons. The lower grades don't feature any rod as Larson70 points out. Very
common was the V-shaped maple reinforcement used at early guitars. Here's a PAF graphic by August Larson of
such a reinforcement dating 1903 patented 1904 which I have taken from Bob's first book:
Author
Comment
BTW, this graphic also shows the earliest version of the laminated brace design: the X-braces, the (single) tone
bar and two fret board extension bars are laminated. The fingers and the sound hole reinforcement braces are
solid. Some other construction features are shown like the barred dove tail joint which I only saw as drawing
but never in reality.
Author
Comment
Back to the V-bar: this is the same reinforcement that could be found at Gibsons before the adjustable Ted
McHugh rod was installed in late 1922. But I don't have any idea who was the first one using this construction
or were it comes from. But it is clear that August Larson filed a patent for this construction and intended to use
this featur obviously (it would be very interesting to learn if Gibson went into any trouble using this protected
construction as they have much fun filing actions against other manufaturers today). While the flat top steel
string guitar actually was not present at this period this graphic shows that August Larson thought about various
construction features which help to withstand a steel string tension at a flat top guitar long before anybody at
Gibson or Martin had any idea of this. Still the top appears to be flat at this graphic having not the pronounced
arch of the well known Larsons.
The second type I have seen is similar to Martin's ebony rod reinforcement but more simple (I guess the Larsons
had a weakness for simple methods): 3 parallel and vertical installed ebony or RW strips rather than a single
square bar. It seems they just hustled the necks over the buzz saw, cutting three slots into the neck in the width
of the blade and glued in the strips - done! I have seen such ebony strips at medium grade '30s Larsons which
had a one piece neck rather than the multiple laminated style neck like this early '30s "Maurer" stamped
Milwaukee Euphonon.
Author
Comment
The high grade multiple laminated necks as could be found at the Euphonons and Prairie States didn't feature
any additional rod besides the lamination as far as can tell.
Author
Comment
Quote:
In the mid to late 30's they did use steel rods on the Euphonon line as neck reinforcement.
Larson70,
I haven't seen any, could you figure this out more clearly: what guitars, what rods?
Author
Comment
Quote:
Quote:
One can only assume that they were just smart woodworkers. Any time you laminate anything it becomes much
stronger. Often without having to add any additional structural weight.
That's correct - the idea of the lamination is adding strenght without adding weight or mass. But the added
strenght mainly is present across the direction of the seam and nearly negligible lengthwise. Concerning the
laminated top braces this means that the glue joint doesn't add stiffness against the top vibration or forces
caused by the lamination. For me this construction means that they wanted to use the denser RW only as a
narrow strip as brace and added spruce strips to the sides to gain a bigger glue joint to the top. A solid RW
brace the way they also used maple braces would have been way too stiff. But the sound character of RW might
have been more attractive than solid maple braces, at least something different. I can confirm that a
BRW/spruce laminated top brace adds a nice strenght and gains a nice and still powerfull tone with higher
trebbles or overtones than a regular solid spruce brace - at least different.
The upright standing lamination adds only stiffness by the conditions of the material itself meaning RW is stiffer
than spruce (although upright standing and quartersawn spruce can be very solid as well). So the ebony/RW
neck rods mainly add stiffness by their own material conditions - not by the lamination. But the lamination
works against any distorsion and is very welcome insofar as neck reinforcement. A special feature is the Vshaped lamination since this kind of lamination is working against distorsion and adds stiffness through the glue
joint - a brilliant construction.
Quote:
This is curious because usually modern builders are trying to keep the weight of the top down... But it would
also weigh more than a taller all spruce brace that had the same stiffness.
John,
The added weight by the RW strips is minor. It should be ointed out that the Larson tops are slightly thinner
than steel string Martin or most Gibson tops. So the actual weight of such a Larson top might be slightly higher
but nothing to consider. At least not as heavy as a modern Sitka top with almost all braces "scalloped off".
Quote:
Author
Comment
Maybe they wanted to increase the stiffness for structural reasons but didn't want to increase the frequency of
the modes.
I think they wanted to add some of the conditions of BRW for the spruce brace by minimal weight or mass
addition. The might have structural reasons in mind to hold the arch of the tops better but I guess they had the
different sound in mind which is gained by this construction. Probably they had both in mind since one feature
always is related to another one.
Quote:
Or maybe they just wanted something that sounded different than a Martin.
Martin still was asleep and dreaming about gut string guitars as these constructions were invented. But stepped
forward to the '30s: it is clear from what tradition and construction basics the Larson guitars, the Martin steel
string guitars and the Gibson flat top guitars came from depending on their very different history and
developement these makers went through. Martin with the biggest experience in the scalloped braced flat top
construction with the fine sound, Gibson with their archtop background and the Larsons with the solid and
reinforced steel string guitar constructions.
A last comment:
Quote:
Minus all the crude inlay work etc. Sorry Carl and August no offense.
OK, their pearl work could have been done cleaner and their inlays finer. But I would still say such inlays stand
for a tradition and a high level of craftsmanship (and the highest one of design work) which should be reached
first without modern techniques and crazy glue. They have their own style and present an esthetical value I
deeply aprreciate.
Author
Comment
Willi
Author
FoolForWood
Comment
#188
[-]
#189
[-]
Hmmm.......yeah....... it seems this little thread is back on track.
And it seems Willi is in top shape again, too.
(01/09/08 5:38
AM)
BHguitars
Henk
Thanks, Henk. I just added two more pics. I thought I have more but I can't find any of them. The "new"
digicams made it much easier to document repairs and guitars but before we bought our first one I didn't save
anything unfortunately. That's when we had the majority of Larsons in our shop. Long time gone ...
Willi
(01/09/08 6:24
AM)
#190
[-]
Larson70
Quote:
In the mid to late 30's they did use steel rods on the Euphonon line as neck reinforcement.
Larson70,
I haven't seen any, could you figure this out more clearly: what guitars, what rods?
(01/09/08 9:58
AM)
Larson70
What I mean is that I have seen steel reinforcements used in the necks of Euphonon made guitars. Similar to
what Martin was using in the 30's. I have seen this on only two occasions. While I was having some neck resets
done on my guitars. Its rare of course. But what Larson 17" isn't. These were smaller squared steel bars. Not "T"
style steel.
#191
[-]
Quote:
Minus all the crude inlay work etc. Sorry Carl and August no offense.
OK, their pearl work could have been done cleaner and their inlays finer. But I would still say such inlays stand
for a tradition and a high level of craftsmanship (and the highest one of design work) which should be reached
(01/09/08 10:09 first without modern techniques and crazy glue. They have their own style and present an esthetical value I
deeply aprreciate.
AM)
Author
Comment
Understandable of course. But think of the level of inlay work that was achieved at the Martin factory. All things
considered Martins work was flawless. On most accounts just plain perfect in every respect. Thats for many
obvious and not so obvious reasons.
As far as the Larson's inlay work goes it was just a personal observation. After seeing the Montuoro guitars up
close I was amazed at how amazing the inlays look. Considering he does everything by hand. And the most
sophisticated tool in his shop seemed to be a calculator He was laying out a Tree of Life inlay when I was
there. And it seems like a ton of work.
The one thing I notice of course with Larson inlays is how crooked and choppy they can be. Most companies
back then were having women do the inlay work. Because as we all know guys women pay much closer
attention to details But again not opposing those guys.
Davids Harp
#192
[-]
Yo, Larson70! You got a name? Or should we keep calling you Larson70? For instance, that's Henk and Willi up
there, people like John and Tony and lots of other names have been in on this thread, and I'm
David
(01/09/08 2:14
PM)
Harp, a J-40, perfect and beautiful/J-18M/1935 R-17/000C-16 dovetail/1944 0-18/1944 0-17/5-16GT/1965 0021NY/00C-16FMBUAE/LXME (Grevened!)/D12-18/Gibson B-25-12-N/Guild F112-N-T
#193
[-]
Quote:
That's correct - the idea of the lamination is adding strength without adding weight or mass.
John Platko
On the top braces it looks to me that they got about an additional 7% stiffness for about 25% more weight. And
more work too.
Quote:
(01/09/08 2:25
PM)
A solid RW brace the way they also used maple braces would have been way too stiff.
They could have fixed that by just reducing the height, especially if they didn't care too much about the weight
of the brace. But if they were using scraps of BR, as you suggested earlier, then the lamination with spruce
makes more sense to me.
Author
Comment
Quote:
I think they wanted to add some of the conditions of BRW for the spruce brace
That might be the real reason they did this. But just what "conditions" are we talking about?
#194
[-]
John,
I will think about your comments. Basically my thoughts are depending mostly upon my feeling and practial
experience - little science view or numbers in the foreground. Although I always try to understand the technical
reasons and circumstances I look at designs and construction concepts more often through my imagination
rather than technical or physical understanding. The reason for this is that a guitar construction and design is
very complex what I can follow or create with my free imagination and feeling much better than coming from
the technical side since I learned that mostly everything could be explained and reasoned - but often the core is
failed.
BHguitars
(01/09/08 4:24
PM)
What we have here is a complete concept that seems to work as a unit. We can try to explain and to
understand single attributes and conditions why the entire concept might work based on single features but
conditions like weight are one-way views which don't work satisfying this way. It is like the imagination of
overtones. You can measure them and say: if they are too disharmonic it's a poor sounding guitar. If they are
too harmonic it's a boring guitar. So how to find the golden center? Nothing to explain or to measure. Insofar I
would say the Larson concept is based on a more solid construction gained by a strong top arch, a tinner top
but a heavier or stronger bracing (roughly). But the bracing is not too stiff or heavy in combination with the
entire construction. It gains the Larson-typical and unique clear sound with a very nice volume and tone color.
The balance of weight, mass, flexibility is present and healthy - otherwise all this wouldn't work so well. So
when we try to understand we always have to consider these sound character and basics. If we mix this up with
other construction basics coming from other concepts they might not be valid in general possibly.
I don't think sound character can be determined by conditions like weight or mass (although influenced). Like
Spanish cedar is very similar to spruce in weight and stiffness as a brace but it sounds different. So a
spruce/BRW lamination might be similar to mahogany in weight and stiffness but probaly very different
soundwise.
Willi
Author
Larson70
Comment
#195
[-]
#196
[-]
Quote:
Yo, Larson70! You got a name? Or should we keep calling you Larson70?
Answer:
(01/09/08 11:52
PM)
Yo, My name is Jeff....
I am new to this thread. I have gone over the posts here. Some things people say seem to make sense. And
some of it seems like a lot of science and not like guitar making at all?
Larson70
I am not a guitar maker. And not sure who else is here other than Willi and his boys. But I would have to assume
it would be really hard to tell things like 7% from 25% without actually building the guitars yourself. And from
that compare and contrast. Numbers are good for accountants.
There are certain things that belong in a laboratory setting. And I personally feel that musical instruments is not
one of them. For instance, centuries of research has been conducted by people trying to dissect the varnish that
was used by Antonio Stradivari. Without too much consideration of the fact that his violins sounded the way
they did because HE made them. I don't think he sat in his Cremona shop crunching numbers.
I do appreciate the interest people seem to have here about these Larson guitars here. But I feel most are
(01/10/08 12:51
missing the point. Judging by their patents its only obvious that the Bros had a clear understanding of what they
AM)
were doing. And strong ideas of where they wanted to go. But under all of that they were woodworking
craftsmen. And progressive artists. Not lab coat wearing scientists that that measured tensile density of their
braces on a daily basis.
This of course is speculation on my part. But I am drawn to my conclusions by the hardest evidence there is.
That their guitars are magical. And are the furthest things from many of these bottled ideas. No hard feelings
toward anyone. I figure why not be honest since everyone else is. And I would rather buy a guitar from a guitar
maker. Not a theorist.
BHguitars
#197
[-]
Quote:
And I would rather buy a guitar from a guitar maker. Not a theorist.
(01/10/08 4:10
AM)
Jeff,
I think almost this entire thread is guitar maker's stuff. But exactly in the moment you post your meaning about
Author
Comment
the guitars and their concepts you are leaving this level because you discuss and appraise a concept. That's the
nature of guitar discussion and chriticism. I understand what you mean by "theorist" but all what we are doing
here is more or less theory in a self reflecting style. I would say a guitar maker or manufacturer (and other
people creating things as well) is located and moving inside a triangle while trying to locate his own position and
intention:
There's the personal back ground, the practical experience as craftsman, woodworker, guitar maker or engineer
or inventor. This is the first corner we could name personal experience and feeling. Second is how he is creating
his product and the way it is constructed until it is manufactured: are his thoughts led by free imagination in the
way of a creative artist or are his thoughts led by physical theories and coherences. I will name this theory and
imagination. A third corner is his understanding of the nature of things and the sense of his personal doing:
historical, traditional or modern, progressive - does he want to stay away from any change, to conserve or to
preserve, to develope, to proceed, to advance, to refine or to invent. This corner could be named preserving
and proceeding. We usually name this entire relation and coherence building philosophy. A similar situation is
present for the user or client when he's asking about his personal point of view.
There are other triangles thinkable describing how to evaluate personal situations and views. As far as I'm
concerned there's also a major point or corner I would name culture, solical and political meaning, the way of
living, how to earn living and the intention what to gain by ones own doing. At least guitar making and making
music is a social-cultural doing and I presume each of us is down into this - otherwise nobody of us would post
or read at this place.
Now after this philosophical excursion I can step back a little closer to your post above:
Quote:
I do appreciate the interest people seem to have here about these Larson guitars here. But I feel most are
missing the point. Judging by their patents its only obvious that the Bros had a clear understanding of what they
were doing. And strong ideas of where they wanted to go. But under all of that they were woodworking
craftsmen. And progressive artists. Not lab coat wearing scientists that that measured tensile density of their
braces on a daily basis.
You hit the main point in describing what all this here is for: understanding. While the discussion would have to
proceed further on at least for me to understand what you mean when saying that most are missing the point
here (what is your point in contrast to other's?). I think this excursion we have here - discussing the Larson
concept - is just one part of the basic question present from the beginning about the arches of top and back.
This already covers several pages but I want to add concerning the Larsons and concerning thoughts on vintage
guitars and the making of these and contemporary guitars.
I feel there basically are two ways to evaluate the making of vintage guitars: The point of view from today,
looking back saying their concepts are one hundred years old now - what has happened and what did we learn
until today? The other is the time machine in which we can take place going back to the period when this
happened including all circumstance from music to craft and everything else what had an influence. This means
we can try to look at things through their eyes. The difference is we either can look back from the presence or
looking forward from the past what makes a huge difference for my person and what I feel is the reason for
Author
Comment
one-sided consideration I don't agree to. The second way - which I basically prefer when trying to understand
about guitar making, concepts, inventions - offers another major opportunity. After we came to an analysis and
evaluation covering such old concepts and former brilliant inventions and creations we can try to step forward
from this point of development we appreciate the most and can move and proceed in every thinkable direction.
That's the core and main point of all this stuff we are doing here I think - and for me every way to proceed from
there is approved and welcome.
Willi
Tonyfrancis M Re: "Flat tops" vs arched bracing
#198
[-]
Thank you to everyone posting here, Your thoughts and opinions are highly appreciated.
Tony
(01/10/08 4:50
AM)
BHguitars
#199
[-]
I just took the opportunity, after having a short email correspondence with Frankie Montuoro yesterday and
just after learning about his shop, to invite him and asking if he wouldn't want to contribute to the forum and to
this or any other thread. Possibly we can welcome a new fellow soon ...
Willi
(01/10/08 6:52
AM)
FoolForWood
Thanks, Willi. I'm looking forward to his first post.
Henk
(01/10/08 6:55
AM)
#200
[-]
Author
Comment
#201
[-]
Quote:
But think of the level of inlay work that was achieved at the Martin factory. All things considered Martins work
was flawless. On most accounts just plain perfect in every respect.
BHguitars
Jeff,
One word to the Larsons inlay work: I know what you mean since the Larson craftsmanship does not have the
same approach to detail as we are used to see at pre war Martins. But the Martin inlays do not reperesent the
finest art of pearly inlay though. Still I'm really impressed by the Larson design work and their inlays in general
even if there's some sloppy part and rough engraving.
(01/10/08 7:37
AM)
There are some threads covering pre war inlay work.
This one is about a "rough" Martin inlay, extending to old pearl inlays and craft: Beautiful 000-28 on the bay...
This one is especially on Larson inlays featuring a very nice Larson couple: Matching Larson/Maurer 00 & 000
I'm going to post there a very beautiful pearl inlaid Larson pick guard - BTW one of the most beautiful
instruments I have seen in the recent past with oustanding beautiful and tasteful inlays.
Willi
#202
[-]
Quote:
John Platko
Numbers are good for accountants.
And that people who designed the bridges you drive over.
Quote:
(01/10/08 9:25
PM)
I am not a guitar maker. And not sure who else is here other than Willi and his boys. But I would have to assume
it would be really hard to tell things like 7% from 25% without actually building the guitars yourself.
It's really not hard to understand how the construction of a brace effects its stiffness and mass. The formal
science behind it is 18th century technology and I'm sure craftsfolk and builders understood it long before that.
Author
Comment
You don't have to be a guitar builder to understand it either. Likewise, you can understand it and still be a guitar
builder.
Quote:
And from that compare and contrast
It's also not too hard to compare and contrast it to other braces used on other guitars. Or compare it with the
common theories for brace construction. Especially when it seems to buck the trend, like this one does. It's
another design point, that doesn't make it bad, just different, and that's what makes it interesting to me.
Quote:
And I would rather buy a guitar from a guitar maker. Not a theorist.
There are some really great makers that use science to enhance their craft. For example, check out Al Carruth's
work. You don't have to choose one or the other.
Larson70
#203
[-]
#204
[-]
Message for John Platko
Are you a guitar or instrument maker?
(01/11/08 10:27
AM)
0021fan
Regarding the Larson construction approach: I would like to learn more about their positioning of the x-brace
vis the soundhole and bridge (i.e., did it vary as much as Martin over the years?). Also, in what ways does the
laminated bracing optimize or otherwise facilitate the arching/doming found in Larson-built guitars? Thanks.
(01/11/08 12:49
PM)
Author
Comment
Arnoldgtr
#205
[-]
Quote:
Also, in what ways does the laminated bracing optimize or otherwise facilitate the arching/doming found in
Larson-built guitars? Thanks.
(01/11/08 1:20
PM)
It's stiffer. No theories required. Not because of the gluing of the lamination (as Willi already indicated), but
because 1/3 of the brace is rosewood, which is considerably stiffer than spruce.
John
#206
[-]
Quote:
John Platko
It's stiffer. No theories required. Not because of the gluing of the lamination (as Willi already indicated), but
because 1/3 of the brace is rosewood, which is considerably stiffer than spruce.
Putting some numbers on that, I have
1.6 X 10^10 N/m^2 Youngs modulus for BF
1.33 X 10^10 N/m^2 Youngs modulus for Red Spruce
(01/11/08 2:58
PM)
So Br is (1.6-1.33)/1.33 = 20% stiffer than RS.
And since only 1/3 of the laminated brace is BR, and therefor stiffer, the result is about 7% stiffer.
(Edit - fixed units)
0021fan
#207
[-]
I understand that this bracing design is stiffer. What I'm curious about is - where in the body construction, topbrace gluing process,etc., is the top curvature executed .. and how does this brace stiffness enable or otherwise
facilitate this curvature, if at all. Thanks.
(01/11/08 3:27
PM)
Author
Comment
#208
[-]
Quote:
and how does this brace stiffness enable or otherwise facilitate this curvature
BHguitars
The top arch is gained or created by gluing on the braces. The braces are radiused and glued onto the top which
is put into a mold. A top without bracing can be easily shaped to a curvature or arch by gluing on curved or
radiused braces. Such braces don't have to be laminated or stiffened by a RW center - solid spruce works well
enough, even if scalloped. A second or additional technique is to dry down the top somewhat what usually
every maker is doing before gluing on the top braces to prevent any top sinkage or dryness cracks. This could be
done easily by storing the tops at a higher place for a while inside a heated room before bracing.
The additional stiffness of the Lason laminated braces is not necessary to hold the top arch - such an arch can
be created easily also by a scalloped spruce bracing. Many Gibsons have a similar arch while braced very lightly
(look at the beginning of this thread). Even some Martins have a nice arch although rarely present between
sound hole and bridge what the Larsons (and Gibsons) actually have.
(01/11/08 4:20
PM)
The construction of the laminated bracing as used by the Larson has been laminated not only for structural
reasons - it's part of a concept where an arch and such a bracing style is creating an unique sound and tone
along with some other features. BTW, the Larsons also used a heavier back bracing. Usually 6 braces rather
than 4 while no. 4 and 5 are flat and wide, holding the back arch at the widest point mainly through their glue
joint. No. 6 mostly is a narrow but tall brace like no. 1, 2 and 3.
Part of the top construction also is, as far as I could notice, that usually the tops are thinner than one would find
at a Martin of the same size. Noticeable also is that the top edges are thinned meaning the top thickness is even
thinner at the edges. This means that the top construction mainly is only at its center more solid - at the outer
places it's as lightly constructed as a Martin or Gibson.
Very interesting are some tapping tests: tapping the top and back shows that a Larson body sounds much
brighter than a Martin body. The overall weight seems to me slightly heavier than a Martin guitar built with the
same woods. But still light, especially very light considering their firmness.
Willi
0021fan
#209
[-]
Quote:
This means that the top construction mainly is only at its center more solid - at the outer places it's as lightly
constructed as a Martin or Gibson.
(01/12/08 12:48
Author
Comment
PM)
Revisiting a pic I posted earlier from F. Montuoro's site - it was noted in earlier replys that the top bracing
arrangement shown (below) is atypical vs. the more usual Larson pattern. I'm curious to know whether the
arrangement shown here is designed for greater strength at the arch mid-point .. or more for sound..or both.
Montuoro is known to have de-constructed and/or repaired quite a few Larsons, thus he may have learned
something that is reflected in his choice of bracing ... any thoughts?
#210
[-]
Quote:
I'm curious to know whether the arrangement shown here is designed for greater strength at the arch midpoint .. or more for sound..or both.
Frankie Montuoro might add some words on his construction in person later at this place. I guess that's much
better than anybody else would do for him.
BHguitars
(01/12/08 1:58
PM)
Above I tried to explain my understanding of the Larson's construction. Although we arched our tops always
from the first guitar we built, we started with a more pronounced arch beginning from the point as we built our
first Larson recreation. But we noticed that there also were other well built guitars featuring a pronounced top
arch. This is when we started to think about such top arches in general and experimented with different styles
of bracing. The Larson style laminated bracing could be considered as a top level construction similar in quality
as the Martin scalloped bracing - it sounds only much different.
In the end the entire concept, at least the bracing style and top arch should create a well working and sounding
unit. Every maker has to find out by himself how to convert the Larsons' ideas and constructions (if he wants) to
his own concept. Theory alone doesn't work. Even as it makes much sense to understand why things should be
done this or the other way every concept should be confirmed and prooved by practise what impact each
bracing style might have to the own instruments and to the personal style of building.
Insofar I can confirm that top arch, top thickness and top tension as well as the bracing always have a structural
and a tonal meaning - it's not possible to divide this relation but it should be evaluated of course.
Willi
Author
Comment
#211
[-]
Quote:
John Platko
Part of the top construction also is, as far as I could notice, that usually the tops are thinner than one would find
at a Martin of the same size. Noticeable also is that the top edges are thinned meaning the top thickness is even
thinner at the edges.
Willi,
(01/12/08 5:55
PM)
What dimensions do you find for the center of the top and the edge of the top?
0021fan
#212
[-]
Copied from F. Montuoro's site re: Larson bracing Quote:
Nothing against scallop braced guitars of course, but through my personal experience I have found it favorable
to not scallop. You may wind up with a lighter braced top, but I feel that's not what it's all about. Contrary to
popular belief, the Larson's built their guitars with thicker tops. Built under tension at quite a severe radius that
(01/13/08 11:56 is equal to the radius of the back.
AM)
Interesting ...
Montuoro
Guitars
#213
[-]
Hello,
Well I finally made it here. Willi was gracious enough to grant me an invite. I will do my best to answer some
questions. This is very exciting stuff indeed. The one thing I always keep in mind when it comes to the Larsons is
this. Just when you think you have figured it out you come across a guitar that sends you back in the direction
you came from. Meaning it can be hard to assume their path. Because at times I am not sure if it was as clear to
(01/13/08 12:24 them either. They loved to explore ideas. Especially with bracing. Virtually there are no two Larson bracing
layouts that are the same.
PM)
Author
Comment
But this is half the mystery. There is something here that is very unique and crucial that thus far I have not
heard anyone tap into. Not just in the conversations on this thread. But in general when it comes to the Larsons
and their building practices. It is in many ways the key to help unlock their trade mark sound. And because of
this it would be best for us to talk it through then for me to just tell you.
We all tend to focus on bracing layout and top thickness etc. Me included. But what lies at the heart of the
Larson ideas is really not as much about bracing and top thickness as it is about? Meaning we need to take an in
depth look at the way the body as a whole is assembled. The guitar is not just a top with braces. And truly I feel
this is a huge part of what they were about. I have been fortunate enough to restore over 200 of their
instruments. Some I received in pieces. I also own some rare Larson birds. All of these are what helped me have
a better understanding.
I want to of course mention I dont know everything. Would never claim to. But there is a huge part of guitar
making that is never talked about. I am excited to see if it is unearthed here.
Again thanks a bunch Willi. This should be fun. Willi seems like a great guy
BHguitars
#214
[-]
A big welcome to you, Frankie!
I will read all your posts with big interest. I'm more than happy to meet you this way and I hope this will turn
out as an excellent experience for you, too.
(01/13/08 12:49 Best,
PM)
Willi
FoolForWood
Quote:
(01/13/08 1:04
PM)
Say that again!
Yep, thanks for joining us.
And Willi, thanks for inviting him!
Henk
#215
[-]
Author
FoolForWood
Comment
#216
[-]
#217
[-]
BTW Frank (is it OK to say Frank?), there's a thread about you, here:
p072.ezboard.com/ftheunof...4672.topic
Henk
(01/13/08 1:07
PM)
Mario Proulx
Can this Larson stuff be moved to the technical section, under its own title? I'd hate to see all this get buried
under a title that isn't descriptive, and in the wrong section, making it impossible to find later.
(01/13/08 1:11
PM)
Montuoro
Guitars
thanks!
#218
[-]
#219
[-]
Quote:
BTW Frank (is it OK to say Frank?)
My name is Frankie. But whatever works
(01/13/08 1:11
PM)
FoolForWood
OK, Frankie it is.
Quote:
Can this Larson stuff be moved to the technical section, under its own title? I'd hate to see all this get buried
under a title that isn't descriptive, and in the wrong section, making it impossible to find later.
(01/13/08 1:31
PM)
thanks!
Mario, this is kind of a strange thread. It started about arched bracing, but it got a lot broader than that. Also, it
Author
Comment
was started in The Vintage Corner, not even in the Tech. Info section, and later when The Log Cabin started, it
was moved to this section. I'm not sure why, but it doesn't really matter I guess, because most members who
are interested in these matters seem to know where it is. And I promise, it will not get buried.
BTW, there's also a Larson thread going on in The Vintage Corner. Perhaps this would fit there, too. I'd just
leave it as is, especially if it's basically about braces, arching, etc.
Henk
Montuoro
Guitars
#220
[-]
Thanks!
Thanks very much for the invite. I do appreciate it. I want to say first off how much I admire the guitars being
built by Blazer & Henkes. They are truly magnificent instruments. I am honored that I am even included in this
thread. Hopefully one day Blazer & Henkes and Montuoro Guitars can collaborate on a build. That would be
exciting.
(01/13/08 1:59
PM)
For now if anyone has any specific questions let me know and I will do my best to answer them.
#221
[-]
Mario,
As long as we cover the matter of arched tops and backs in general including Martins, Gibsons and now Larsons
I think this is the right thread - perhaps it could be moved back anyway to the technical section as you suggest.
BHguitars
But I would welcome always a new thread on Larson guitars in general maybe at the Vintage Corner covering
the guitars and their constructions. Especially since there are some Larson fans present plus Bob Hartman in
person.
Quote:
Meaning we need to take an in depth look at the way the body as a whole is assembled. The guitar is not just a
top with braces.
(01/13/08 2:29
PM)
Very well said. This is how I want to look at building concepts, too. Insofar it really should makes sense to start
from a beginning as far as Larsons are concerned directly.
Quote:
Hopefully one day Blazer & Henkes and Montuoro Guitars can collaborate on a build. That would be exciting.
Author
Comment
Thanks for the flowers, Frankie, but indeed, that would be an exciting project. As I said: this forum opens gates!
Willi
Montuoro
Guitars
#222
[-]
Its really amazing how much focus is put on the soundboard and its bracing. This is of course a critical aspect of
the guitars construction. But in dealings with Larson instruments all bets are off?
Why do I say this?
(01/13/08 2:40
PM)
Well I have worked on many "Ladder" and Z-Braced Larsons that dare I say, sound incredibly more defined and
robust than most pre-war Martins or Gibsons. These Larsons are going up against the famed Scalloped Bracing
design with their Ladder braces etc. And in my opinion still manage to come out on top. Its a matter of opinion
of course. The Martin sound is really what people are accustomed to hearing. The Larson tonal quality is still
very unfamiliar to most.
With Larson guitars its very important to focus on the Back Plate and its bracing just as much as the Top. The
back on a Larson is its own universe all together. And has a huge impact on the way those guitars sound.
0021fan
#223
[-]
Hello Frankie .. welcome! Another enthusiast here .. I look forward to learning more about Larson-built
instruments. I'm not a luthier ..so my questions will be quite formative in nature. Maybe one of these days I'll
get to see one in person.
(01/13/08 3:19
PM)
XBrace
#224
[-]
I've read all of this topic with great interest and wondered if Willi, John or anyone else would like backtrack to
the topic's initial starting point ie "flat" v arched bracing. In reference to top bracing where might I be missing
something in this line of thinking ?
Say you were to replicate a '30's D28 top with period correct radius starting with unshaped braces. After the
scalloping is done, wouldn't the brace material that is removed, cause the braces to become more flexible [
after all that's the point of the process ] and so the radius of the top change from the planned curvature ?
(01/13/08 7:56
PM)
Drew ~ Hobbyist Builder
Nth Coast NSW Australia
Author
Larson70
Comment
#225
[-]
#226
[-]
Quote:
Yes Frankie great to see you here. Lots of nice folks.
(01/13/08 9:18
PM)
John Platko's question:
Quote:
What dimensions do you find for the center of the top and the edge of the top?
Some quotes from Frankie:
Quote:
BHguitars
Contrary to popular belief, the Larson's built their guitars with thicker tops.
Quote:
(01/14/08 2:34
AM)
We all tend to focus on bracing layout and top thickness etc. Me included. But what lies at the heart of the
Larson ideas is really not as much about bracing and top thickness as it is about?
Quote:
With Larson guitars its very important to focus on the Back Plate and its bracing just as much as the Top.
First I want to repeat that the key concerning the understand about guitar construction is to get an idea or
imagination how and why the entire construction is working. Insofar the entire guitar including several
construction features has to looked at. This may not easy to do since the Larson guitars feature many details
which are unique or in other words: the Larson brothers were inventors experimenting always and their ideas
often were contrary to those basics we learned from the Martin or Gibson buiding history and their concepts.
For my understanding the back and also the sides including the side shape always stand in relation to the top.
As Frankie figured out the Larsons might have been consistently inconsistent. So it may be hard to figure out
Author
Comment
any specific basics since the guitars differed of course alone during the building periods. Maybe Frankie wants
to add here his experience especially if this is not what I learned.
Presuming that I'm interested mostly in those Larsons built during the later period beginning around 1930 I feel
that the Larson constructions are at it's best at the guitars bigger than 15" or at least 15". My favorites are the
16" 14 fret guitars and larger although the 15" 12 fret instruments can be really amazing. For this reason we
concentrate for our recreations at Larson constructions valid for 15" and bigger and their later building period
after 1930. For the 16" and 17" guitars we prefer the bracing pattern shown above either laminated
spruce/BRW/spruce or solid spruce. The pronounced top arch is the first thing to start with but I personally feel
the top thickness is important for our Larson re-creations as well since together with the bracing and stiffness
of the wood it creates the top tension which I feel is the main part or the first level of sound creation. Back,
sides and neck should be designed in coherence to the top. This as a simplified rule at excample: the back
should be constructed this way that it will be able to respond the top vibration the best but pointed out once
more - top and back create the same unit.
Measurements are not taking so much room at our building process. So I rather tend to get an idea about top
tension and thickness by my hands and feeling. As basis I start with a uniform or standard top thickness of
exactly 3 mm ~ 0.118". This is what I mostly measured at '30s 15+" Adirondack Martin tops and this is what I
prefer the most for new guitars. Starting from this point or measurement I say thicker or thinner. BTW: those
Adirondack top 16" Gibsons I like the best also measure 3 mm as well as my favorite OMs and 12 fret 000s. My
observation was that those 15+" Lasons of the '30s had slightly thinner tops than 3 mm what means for my
feeling 2.8 mm ~ 0.110 is a thin top while 3.2 mm ~ 0.126" is really thick for an Adirondack top. The last big
Larson I measured was this one we had recently in the shop:
Author
Comment
The top thickness was slightly less than standard but I have to add that I only measured around the sound hole.
This guitar is unique and a one-of-a-kind Larson anway with rather deep sides but I had the same observations
at other similar Larsons in the past.
As I described before another observation I made is that the tops are thinned at the top edges. This is hardly
possible to measure but I describe it in other words how this is created in a simple way: when the top has been
Author
Comment
glued onto the rims and the binding was added the binding and edge inlays have to be levelled. This could be
done creating the same level with the top surface (or radius) or - now this is what I noticed - the binding and
edges are levelled even creating a stronger radius. If one is holding a ruler on the top this is visible clearly. Also
that the stronger top radius reaches a little into the top itself. The advantage is very simple: the binding can be
levelled very fast and straight forward without leaving any tooling marks at the inner part of the top while the
top thickness is reduced in one and the same operation at the outer part. The idea of thinner top thickness at
the edges depends on the assossiation of membrane similar suspension - a construction feature which could be
noticed at other wood body musical instruments as well. While I have noticed this feature also at other old
guitars including Martins and Gibsons it could be noticed at the Larsons the most. But nothing to measure, it's
just a simple operation step which makes much sense IMO.
Willi
Tonyfrancis M Re: "Flat tops" vs arched bracing
#227
[-]
#228
[-]
Welcome Frankie, Glad you can be with us!
Tony
(01/14/08 5:29
AM)
Montuoro
Guitars
(01/14/08 9:18
AM)
Most of the Larsons I have measured seem to all be slightly different from one another. I have had the
opportunity to measure the thickness of two individual guitars that unfortunately had to have the soundboards
replaced. They were within .010" of one another. And from what I had gathered there was no sanding or
reconfiguring of the original thickness of either top.
I do agree with Willi in regards to the larger guitars being a bit more consistent. Meaning post 1930 made
guitars. Its interesting if you observe completely intact original Larsons you will often times notice horribly large
sanding scratches and sometimes gouges on the soundboard under the original finish. Especially on the 30's
guitars. The Bros were in their 70's at this point. Most likely had horrible lighting conditions in their shop. The
point I am trying to make here is this may be yet another sign of their lack of specific building concerns. Adding
to these measurement differences. On pre 30's instruments of guitars under 15" you will often see Tops on the
thinner side. Under .110" at times. I have even seen a Maurer at .090"
I actually have a 1939 17" Prairie State in my shop at the moment. As well as the two original soundboards off
original instruments. I will go over all three again. From my last dealings of measuring all three they are
completely different. I actually have measurements of a Top at .130
Super thick for Adirondack. The mystery lives on . If these were guitars with scalloped bracing this would be
more of an issue. The added tension on these tops allow them to stay put at almost anyone of these
thicknesses. I will check back later with all three of those dimensions.
Author
John Platko
Comment
#229
[-]
#230
[-]
Welcome Frankie.
Anyone have a side profile picture that shows the arches?
(01/14/08 4:01
PM)
Davids Harp
So let me see if I'm seeing this correctly. Here are four or five posts in a row, offered by Willi, Henk, Mario
Proulx and Frankie Montuoro, with a comment from John Arnold a little way up the page. And people wonder
why I like to hang around in here!
David
(01/14/08 6:52
PM)
BHguitars
#231
[-]
Thanks, David. I always feel at the right place when i find your post.
Quote:
Anyone have a side profile picture that shows the arches?
(01/14/08 7:08
PM)
I don't think I saved such a Larson pic. Maybe Frankie? I posted this one showing a side profile of an arched top
at page 6 of this thread. Possibly I can take some more tomorrow. So the camera angle creates a somewhat less
top arch but since this is a Martin style guitar the arch is a little less in comparison to a Larson style arch
especially at the back. Some other pics shown also at page 6.
Author
Comment
Willi
Author
Comment
Montuoro
Guitars
#232
[-]
I can offer some pictures as well. This is going to sound strange. How do you do that on this website? For some
reason its not obvious to me.
(01/14/08 9:27
PM)
#233
[-]
Frankie,
Flat5sub
The key is that you've got to sign up with a photo hosting site first (for example, photobucket.com,
voguehost.com, etc.). These sites are often free of charge.
Basically, you'll use their interface to post the photo on their site, and link to your posted photo by clicking the
"image" button here on EZBoard, and then paste the photo's URL in a little window.
It's much easier than it sounds, but you have to get set up with a photo hosting site first.
(01/14/08 10:01 Jim has some tips in the FAQ section:
PM)
p072.ezboard.com/ftheunofficialmartinguitarforumfrm19.showMessage?topicID=29.topic
Looking forward to your pix.
-Flat
XBrace
#234
[-]
Quote:
I've read all of this topic with great interest and wondered if Willi, John or anyone else would like backtrack to
the topic's initial starting point ie "flat" v arched bracing. In reference to top bracing where might I be missing
something in this line of thinking ?
Say you were to replicate a '30's D28 top with period correct radius starting with unshaped braces. After the
(01/14/08 11:33
scalloping is done, wouldn't the brace material that is removed, cause the braces to become more flexible [
PM)
after all that's the point of the process ] and so the radius of the top change from the planned curvature ?
Drew ~ Hobbyist Builder
Author
Comment
Nth Coast NSW Australia
I'm not sure if anyone is interested in making a short comment on the above quote. But I'm interested enough
in the original topic to ask it again. At the expense of quoting myself.
Willi, as a secondary question, are you not convinced that scalloping is such a good methodology for a desirable
outcome ?
Arnoldgtr
(01/15/08 1:46
AM)
#235
[-]
Drew,
Most of the guitars I have built have scalloped braces, and I have not noticed the 'flattening out' that you
describe.
I believe that is because of two factors...the clamping method and paying attention to the moisture content.
I always clamp the braces with curved cauls underneath the top (and back). They are clamped full height, and
scalloped later. The curved glue joint is already established.
Even so, it will all be for naught if the moisture content is ignored.
As Willi has described in his posts, I also make sure that the top is very dry when the braces are glued on. If the
top shrinks after the braces are glued on, it will flatten out.
The importance of moisture content cannot be emphasized too much.
John
BHguitars
(01/15/08 4:12
AM)
#236
[-]
... as John describes. As some of the pics I posted at the beginning showing different Martin top arches or top
conditions I believe this was a matter at the Martin factory as well since I notice big differences at some guitars.
My understanding is that these differences might depend mainly on winter and summer built Martins meaning
in the different moisture content of the tops. Although Martin might have paid big attention to this matter of
course it may have been difficult for them to keep the factory production running during rainy summer or
spring season still having low moisture content present at the tops. The dry condition without modern climate
control (which I mistrust BTW) only done by the room heating seems to be a big issue. (Another question I have
since a longer time is if the mid '30s weren't rather dry years with noticeable less rain and lower humidity at the
east side of the US considering the average excellent crack free top conditions I notice especially at mid '30s
Martins).
Personally I'm feeling very comfortable when I notice no or a very slight increasing of the top arch after doing
the scalloping depending on the rules John described above. I feel this is a very important point during the
construction we pay big attention to and that I try to describe as follows: we dry down the tops before we
brace slightly more than we expect low humidity during dry periods will cause in the future (estimated) to
prevent any issues, sinkage or even cracks. When the tops have been braced and the braces are going to be
shaved and scalloped we choose a dry week with good weather in winter for this operation. We speed up to get
all tops done and glued onto the rims before the tops might have the opportunity to change their arch. When
the tops already are glued onto the rims the top arch is saved and won't change much in the future caused by
Author
Comment
humidity.
Quote:
Willi, as a secondary question, are you not convinced that scalloping is such a good methodology for a desirable
outcome ?
Drew,
Of course I am. Although for wood body acoustic guitars I see 4 major construction concepts which have been
developed more or less independently: around 1850 the Torres constructions featuring the classical fan bracing
and the Martin constructions featuring the scalloped X-bracing. Early 20th century the Larson inventions with
"flat" tops but pronounced arches and their bracing concepts and the last one, the carved tops by Orville
Gibson. While personally I'm not into classical and not much into archtop making there are the Martin, Larson
and Gibson concepts left for me (plus some special constructions like the ladder braced 12 strings). While
Gibson as maker and inventor might be somewhere in the middle of the Martin and Larson style I look at each
of these three makers as inventors of the modern steel string guitar featuring independent and superior
constructions and designs - and I like them all.
Willi
XBrace
#237
[-]
Thanks John, the way you describe the process above gives me a better idea of what's involved. I thought I
remembered you posting something like that way back but with the length of this topic, I got the description of
what you do mixed up with what Martin does ie glue up CNC scalloped braces on a a flatboard.
(01/15/08 5:33
AM)
I thought the only difference was that you were using radiused but unshaped braces on a flatboard. But the
major difference is the shaped caul and extremely dry timber.
#238
[-]
XBrace
Willi, thanks for the explanation. The last paragraph really gives a good summary as to your viewpoint on
various designs/ builders. I now understand your approach. As I said to John, the length of this topic can cause a
bit of confusion as to what various people are saying in their posts. Due to it's set-out, the topic has to be read
and reread very closely.
(01/15/08 4:34
PM)
I'm in a very small group of people on this forum that live in a part of the world where minimum humidity in
"winter" is 50%. At the moment it's 99% and will be for at least 2mths. I've noticed that tops on guitars coming
from dry climates / workshops eg Martin ~ Larrivee actually absorb large amounts of water. This causes bulging
around tailblocks and ripples around other stress points. I actually keep 200g of silica beads in my guitar's
soundholes and have to reheat it every weak to remove moisture. Tops on guitars built here definitly flaten out
Author
Comment
even at 28' radius.
If you can build for dry conditions, then there could be some methodology for building for humid conditions.
Increase the curvature of bracing relative to dry climate guitars ? Maybe the best outcome I could expect is
similar to a Martin "summer" build from the old workshops.
Another aside Willi, I've often seen topics posted on how Martin used to control humidity in the old factory
without definitive answers. Your explanation of a "summer" and "winter" guitar shows they couldn't, they just
had to adapt to the environment. Also your going back to 1930's climatic data is getting very deep into the
history, using an interdisciplinary study. Sort of like taking the knowledge of the process of tree growth related
to climatic conditions, with it's affects on desirable timber stock and applying into to a man made process, with
it's affects on guitars.
#239
[-]
Well, I'm sad to have missed this thread. I haven't been monitoring the "log cabin" for discussions about bracing
configurations.
John Thomas
In any event, cool thread. Oh, and welcome, Frankie!
I'm actually set to X-ray my 2 Larsons (a 14. in 541 and 15. in 551). That should give us a good view of the body
configuration.
X-rays of 1932 L-00 and setup activities
(01/15/08 11:13
X-rays of 1943 SJ, 1944 LG-2, 1946 SJ, 1927 L-1, 1930 L-1, 1936 L-C
PM)
.... John
www.johnthomasguitar.com
Please visit bannergibsons.com to see what Willi, Travis, and I are doing!
Davids Harp
#240
[-]
Jeez. And here we been screwing around with lightbulbs and tinfoil.
David
(01/16/08 12:19
AM)
Author
Comment
#241
[-]
Quote:
FoolForWood
Jeez. And here we been screwing around with lightbulbs and tinfoil.
(01/16/08 5:11
AM)
Yeah, but remember that there might be some of us who don't have an X-ray machine close at hand. Plus I
wouldn't have wanted to miss your contributions for the world, David.
Do keep those comin' too, folks!
Henk
#242
[-]
Quote:
FoolForWood
Well, I'm sad to have missed this thread. I haven't been monitoring the "log cabin" for discussions about bracing
configurations.
(01/16/08 6:04
AM)
John (T), this thread was in your favorite section (VC) from 1/23/07 until the first week of April, virtually always
on page one.
Henk
Montuoro
Guitars
#243
[-]
Gentlemen,
Sorry for being tardy here on the thread. I have been quite busy at the shop and that has all my attention at the
moment. I have lots I would like to share. I just need to get caught up a bit. And yes it would be real great to
have an X-Ray machine!
(01/16/08 9:27
AM)
Author
Mario Proulx
Comment
#244
[-]
#245
[-]
#246
[-]
No need for an expensive x-ray machine! All you need are these....
(01/16/08 11:26
AM)
FoolForWood
Henk
(01/16/08 12:58
PM)
martintones
So after reading this thread, each day for the past few weeks, and trying to understand the concepts, I find
myself looking at my new Martins to study the arching, especially on the top.
I find myself depressed that there's not much between bridge and soundhole, because if I read things right,
arch there contributes to the best sound.
(01/16/08 2:20
PM)
Is it hopeless if the top is fairly flat?
BHguitars
#247
[-]
Quote:
Is it hopeless if the top is fairly flat?
(01/16/08 6:40
PM)
I feel it is a must that the bridge level is above the rim level meaning the top shouldn't be sunken in at the
bridge. I've rarely seen old Martins with a bridge at the center and at its bass side being lower than the rim
level. The treble side wing mostly is pulled down mostly because of the pick guard shrinking. But even if the
place between soundhole and bridge (or the soundhole itself) looks somewhat pressed in or sunken in and a
normal buckle is visible down the bridge this all is working well. But I don't think so with bridges or top
conditions with the bridge being lower than the rim level.
Author
Comment
Willi
#248
[-]
And you thought this thread was dead! Can't let it go, it's too interesting. I thought I'd post these photos of
Martins
radius board for the back and top, at least I assume that's what they are. I use the back for for all D size guitars
and it provides a nice radius though I've never measured exactly what it is. The photos, though lousy, show
dates.
The top board is flat, not sure exactly what it was used for but it's nice piece of mahogany, that's for sure. I got
them years ago when somebody at Martin was cleaning things out and decided to sell some of the old junk. My
BruceHerrmann good fortune I guess. The photos show a bit of the radius of the back but it's hard to photograph. See what you
think....
Best
Bruce
(03/28/08 6:38
PM)
Author
Comment
Author
Comment
http://www.redshift.com/~gibson/topform1.jpg
Author
Comment
Author
FoolForWood
Comment
#249
[-]
Wow, Bruce!
Old junk, huh? Depends how you look at it. Not to me, it ain't. Apparently not to you, either.
(03/28/08 6:45
PM)
tomf14
Henk
#250
[-]
Ah, the thread that will not die! Must admit I have a fondness for this thread too.
My McAlister OM28 Vintage Series has a definite arch to the top, and perhaps that's why this guitar is the
(03/28/08 9:28
PM)
FoolForWood
loudest, most responsive OM I've played
I've got four OMs in the herd, all top shelf, but there's
something about that McAlister that I keep going back to. Could it be due to the arch? Don't know, but my
guess is that's definitely part of the explanation.
#251
[-]
Classical guitars are often built on a solera. In that case the back is glued on last. Most (not all) steel string
builders do the back last, too. (Both at once, anyone?) But Martin traditionally does it the other way around.
Can we say the board is sort of like a "back solera"? Of course, on the back there's no extension for the neck
plane, like true solera's have. And dovetail bodies start without a neck anyway.
(03/29/08 10:50
Author
Comment
AM)
Henk
Dave in Tejas
#252
[-]
Those are neat work boards.
(03/29/08 2:07
PM)
I don't know if it is just me, but I think the trend is to glue the back first, so the body will be open to clean up
the squeeze-out, and trim everything up real tidy, before closing up the box.
Modern guitar buyers have become very picky about visuals, any smear of glue is a horror.
I would prefer to glue the top first.
#253
[-]
Hello Willi,John,Henk and others i thought i would keep this thread going by adding some pictures that i took of
my 38 00 that belonged to my granddad to get your alls opinion on the arches that it has.
toyota884runne
r
(04/22/08 10:28
PM)
Author
Comment
top arch
top arch again
Author
Comment
back arch
Author
Comment
side view of the bridge and soundhole area from the bass side and yes that is the original bridge saddle and
bridge pins.
looking forward to hearing your comments.
FoolForWood
#254
[-]
TR, on my screen the pictures are very dark. Also, a little light from behind (the guitar), e.g. from a window,
would help.
Henk
(04/23/08 10:16
AM)
here is some better pictures i hope.
toyota884runne
r
(04/23/08 11:11
AM)
Top arch
#255
[-]
Author
Comment
Back arch
keep in mind that this guitar was built in June of 1938. Martin started building with the neck block and sides on
Wednesday morning June, 8th, 1938.
toyota884runne
r
#256
[-]
The humidity environment right now that the guitar is in 48%. The guitar has the one top crack but the crack
was not because the guitar dried out it was from an accidental blow by my elbow.
(04/23/08 11:12
AM)
FoolForWood
#257
[-]
Author
Comment
Yeah, that's better. This looks like what Willi did, earlier in this thread. It would be nice if he chimed in, but
he might not be "available" right now. Perhaps I can say something, for the time being.
The arches shown in the pics are across the grain. The back shows the arching caused by the arched transverse
braces, and the top shows the arching caused by the bellying below the bridge under tension. And as we've
(04/23/08 12:25 learned earlier on, drying the plates just before gluing the braces, will give some convex arching, too.
PM)
Interesting, and adding to these pictures, would be showing the the top (and back) in the long direction, from
neck to tail. A side view with a long straight edge on top.
Henk
toyota884runne
r
(04/23/08 9:32
PM)
#258
[-]
Author
Comment
Author
Comment
FoolForWood
(04/24/08 5:30
AM)
#259
[-]
Now we're talkin', TR!
To me the guitar looks pretty healthy for its age. There's some of the usual distortion in the top, caused by the
string tension, but that's normal. I've actually seen it worse in some new guitars. And remember, no distortion
at all would mean the guitar is likely overbuilt and not very responsive. I do remember Willi showing one
thirties example where the bridge did not tilt forward at all, but that one might be out of the ordinary. It
probably had a stronger than usual arch to begin with. Well, I guess I have to reread this thread for the exact
details. John builds with the apex of the arch in front of the bridge, to compensate.
The back has kept its pronounced and smooth arch well.
Now let's see what the masters have to add.
Henk

Comment - Stuff You`ll Find Here

Transcription

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