February 2015 Turnings - Avon and Bristol Woodturners

Sponsored by Henry Taylor Tools
February 2015
TURNINGS
Established 1989
Official newsletter of
Avon and Bristol Woodturners
Affiliated to the Association of Woodturners of Great Britain
Contributions to “Turnings” are accepted in good faith but the inclusion of individuals’ views
and comments does not imply endorsement by Avon and Bristol Woodturners
In this edition
● An oval, but it’s not cricket
● Ray’s treatise on particle physics
● Helen’s pens
● Thoughts on production turning
● Spotlight on kevin
Don’t forget you can read all the Club History to date in one place on our website at:
www.avon-and-bristol-woodturners.org.uk
Simply go to the About tab and choose Club History
ACKNOWLEDGEMENT
Avon and Bristol Woodturners gratefully acknowledge the generous support of Magnox
(Oldbury Power Station) for the printing of “Turnings”
1
From the Editor
quests from other members who had
read his previous article on “an eggshaped oval”.
As I have so often said, each one of us
has (whether we know it or not!)
something unique to contribute to the
general knowledge of the club as a
whole and whilst time for “networking” (what a horrible word that is!) is
necessarily limited at most monthly
meetings, writing for Turnings proirst, may I offer my thanks to vides another avenue to allow memRay for writing an appraisal of bers to put forward ideas, propound
theories (and maybe have them shot
Mark Sanger’s presentation
down!), give or seek advice and in
and to John for providing photos of
general to have “conversations” with
both Mark and the competition eneach other with a month to think of a
tries. It seems that I was probably
suitable response - not a bad thing for
one of the many people who contracted the strain of flu that was able those of us who are not nearly as verto bypass the anti-flu injection which bally nimble as we used to be.
those of a certain age were given last
I hope then that this encouraging start
year.
heralds a new departure which will
continue throughout 2015 and beyond..
Unfortunately, it seems likely that I
will have to call upon the services of
Mike
willing volunteers to cover future
club evenings for, unlike the majori********
ty of club members, the move from
“Tell me and I forget,
Thursdays to Mondays suited me
perfectly. For a number of years I
teach me and I may rehad been wanting to engage in another activity but this involved meeting
member, involve me and
every week, so I was more than
I learn.” (Benjamin Franklin)
pleased when the change to Mondays
By Ray Mellett
was made. As fate would have it, I
was on holiday when the decision to
have always been interested in the learning
revert to Thursdays was taken,
process. From an early age we start by observation, aural and visual, progressing
though I imagine I would have been
through
imitation, resulting in smiles and guroutvoted anyway.
F
I
While it might be possible occasionally to skip one week “now
and then” there’s no guarantee I
will be able to do this, so it’s safer
to say I won’t be attending any
more Thursday meetings.
I will, of course still continue to edit
Turnings and hope that I can rely on
members to provide me with a plentiful supply of copy to make your
newsletter informative, educational
and even perhaps entertaining.
In this I have been greatly encouraged by recent contributions and I
was especially pleased to read that
Dave Smith’s piece in this edition
had been written in response to re-
As part of my work I trained as a trainer,
taught our overseas customers before representing the company overseas in a
technical/managerial position for quite a few
years, learning Australian, Swedish, some
Swiss dialects, hence my corrupted vocabulary. In order to do so, I had to understand
the learning process, and hence speak the
“King’s English” slowly and deliberately rather than my broad Nempnett Thrubwellese
Zummerset in explaining and demonstrating
the functions and servicing of the various
elements of the weapon system. But all the
time, one looks for the students’ understanding feedback. Then entering academia
was a further technique, where one cannot
ignore the cultures! But failure to understand the basics and intricacies of the individuals’ learning process renders all this in
vain! As we all know from our work experience, a good “doer” does not necessarily
make a good manager. Similarly, in our field,
as we all are aware, a good turner does not
necessarily make a good I instructor or demonstrator. However, the club has been generally very privileged in the high quality of
those we have witnessed, either at the Club
or at the Mill. We are also very lucky to have
those MCWT Tutors at the Mill who continue the excellent work started by Max , Dennis, (White and May) Alan, Tich et al. They
patiently devote their time to sharing their
skills and enthusiasm in woodturning, and
ensure the very high standard of achievement by their students. It is always a pleasure to see and share a student’s pleasure at
mastering a technique that previously he or
she would never have contemplated, being
proud to be able to hold it up and say “I
made that”. We know that elation, and it’s
that which keeps us going.
One of the important aspects of tutoring is
to inspire confidence - to help overcome
that inbuilt “fear of the unknown”. Once, as
a routine at the first lesson I asked a lady
gling, blowing raspberries, etc. Whilst we can’t pupil why she had joined the class, and
remember those very early days, we do rewhat her expectations were. I got a rather
member some early attempts, and those verunusual, but truthful answer. “I’ve come to
bal distortions which for some remain with us
discover myself”, she replied. She did that,
for life (my daughter’s version of “Pappy”
began to believe in herself, management
(grandfather) was “Happy”- little did she
recognised her skills and development poknow!!) That’s the “sound input stage”, which tential and promoted her. We remained
improves as our hearing develops, and our
friends for many years. When at the Mill,
outputs get more accurate as our brain and
and not repairing or servicing the kit there, I
vocals improve. Our “best” period for language sometimes wander, observe, and chat, and
(dialects included!) is before our tenth birthwitness this student elation, sharing it with
day, but loving care and stimulation vastly im- them is both a pleasure and a privilege. As I
proves our ability to learn (just observe your
used to tell all my students, “if learning is
young grandchildren!). When overseas, I was
not a pleasure, you ain’t really learning, but
amazed how my very young children soon be- just going through the motions!” And we all
came multilingual, and would carry on conver- remember being told by our gurus that
sations with visitors simultaneously bilingually. turning is too expensive a hobby for it not
However I learnt you could only claim to speak to be enjoyable. So as Dennis and Benoit
another language when you could think in it
will tell you, get your eye in first thing by
before speaking, thus bypassing that cumbermaking something simple, and then give it
some translation process! (My priority was to
to Lorraine for Pick a Peg. It’s a Win-Win
be able to get my beer, bed and food,in that
situation, and you have, as themed in the
order, first!)
“Bucket List”, “Made Someone Happy!”
2
PRODUCTION
TURNING
By John Ruffle
I
guess that most club
members will not consider themselves to be
“production Turners”. Indeed, many would find it far
too uninteresting to repetitively turn the same item.
However there may well be
times when those who are
much more inclined to the
free spirit of creative turning will take on a production
job or two, if only to help
fund what is, when all is said
and done, an expensive pastime.
Even if it is undertaken only occasionally, it is important to adopt a
particular kind of working style in
order to make a realistic profit and
to avoid feeling resentful over the
time take up with what may be one
of the less interesting aspects of
turning practice. This includes
working in the most efficient way
possible, whilst maintaining the
highest possible standard of production, it is important to source
materials in a business-like way,
also making sure that the finance
work out satisfactorily. If, on the
first order, you source cut-price
materials and pass on the saving to
the customer, you come unstuck
when, next time, you have to pay
full price for the timber.
How much to charge?
The first thing is to negotiate a realistic price. If you under-price, it
may seem to be no big deal on the
first order. However, if the same
order comes back over and over
again, and the profit margin is unrealistically small, any enjoyment in
doing the work will soon evaporate
and be replaced by resentment or
discontent. I remember, as a youngster, working in the dispatch department of a large printing company
when a team of work-study consultants came to watch. I was warned by
an older colleague who was supposed
to keep an eye on me, “Slow down
John. If you do it today, you’ll always have to do it”. This is a maxim
that bears thinking about in the context of pricing for a job, and sometimes of taking on the job at all.
Sourcing materials
Next to consider, is the sourcing of
materials. It is no use routing around
the workshop and finding enough
timber that you paid peanuts for five
years ago. Even if that works out the
first time, next time it will require
proper money for the materials, and
your pricing will be way out! Your
pricing always needs to be based on
the current price for new timber, with
a slight mark-up to cover any wastage or sudden price-rises.
It is vital to know where you can obtain the right materials, time and
again, at the right price. It is not remotely helpful to use a supplier, even
if he is cheaper, if he is unlikely to be
able to go on supplying what you
need, or if he is likely to keep you
waiting for weeks before you can
start the job. Source a renewable supply of materials at the quoting stage,
even if it pushes up the price a bit.
Get into a good rhythm with your
work.
Because, in the course of production
time is money, an efficient work flow
is important. It is a good plan, not to
finish one object at a time (except,
perhaps for the first one), but to complete one process on all items, if they
are complex, and then to move on to
the next process. This saves time, for
example, in changing from spindles
to faceplate work; from turning to
finishing, over and over again. This
wastes time, and can, indeed, encourage inconsistency in the work.
Check your work carefully
Even if it involves repeating something, it is better that you find out
about a problem than to leave your
customer to discover a fault, with
3
potential for dissatisfaction and
negative publicity.
Make sure you get paid promptly
Deliver an invoice with the goods,
which clearly states the credit period allowed, and if payment does
not arrive on time, follow it up with
a statement which draws attention
to the fact that the invoice is overdue. The best option of all is, of
course, to require payment on delivery, but that is not always realistic in today’s world.
Eggstatic.
By Ray Mellett
A
s Mike stated in his last editorial, the purpose of Turnings is to
convey other members’ views,
opinions, experiences and knowledge for our mutual benefit - a bit
of symbiotic relationship between
members. It was in that spirit that
reading Turnings over a pint and
whilst listening to some great trad
jazz, I forced myself to read, and
attempt to develop the “perfect
egg”.
Alas, I failed, and I thought, obviously erroneously, I was reasonably
intelligent!
Notwithstanding, ever the pessimist, I continued to doodle on my
notepad with eggy shapes – playing
with curves. Luckily, I was delivering some of my friend Alan’s eggs
from his free range chickens to a
friend, so I measured them - length
and width, did a statistical analysis,
and concluded that the average
width was 43 mm (max 46 mm)
and the average length 57 mm (max
58 mm), whilst the calculated relationship of the width to the length
(to give a “shape factor”) is 3/4!( I
accept that the statistical sample of
6 is low, but presumably, as turners, we only entered into this calculation to turn a lifelike wooden egg
look-alike, and hence this minor
detail is “interesting but irrelevant!”. However, this statistical
analysis is of no use when designing an egg cup, because the egg
cup has to accept the biggest egghence the only essential parameters are those of the biggest egg!!!
So using my calculation to spindle
turn a realistic wooden egg, (using
the skew of course!) is to round
down the blank to 45 mm, mark the
first cut off point with the thin parting tool, then add 15 mm (i.e. 1/3
W since L =4/3 W) to the 45 mm
width to give 60 mm length, form
one end into a half sphere and the
other end into an ellipse! Egg done
(in less than 10 minutes?) with no
complicated calculations.
(Being an inquisitive engineer, I
decided to see if anyone had done
an academic study of eggs.
Guess what? At least 70 academics have
produced studies of hens eggs!
(see
http://www.pjbs.org/ijps/fin798.pdf
for just one example)
My non academic study leads me to
conclude that a chicken egg is approximately 45 mm wide by 60 mm
long in the shape of a semicircle
upon an ellipse. Simple.
Hoping reading this humble contribution does not leave you shell
shocked, but rather more eggstatic!
How fitting that a simple egg should be
not only the embryo for another chicken
but also for no fewer than three articles
on the subject of their shape. Mother hen
would no doubt be flattered and not a
little amused to learn that we humans
expend so much energy and effort into
doing what she does so easily and without any thinking at all.
Ed
Last month’s demonstrator - Mark Sanger
By Ray Mellet - photos courtesy of John Ruffle
A
s a Club, we are
so lucky to be
able to attract
such talented professional turners. Mark Sanger
was the recent demonstrator to share some of
his secrets with us, especially his unique and
beautiful teardrop hollow forms, as we were
able to sample and
touch.
This well respected
Devon based world class
creative professional
turner specialises in creative turning incorporating texturing with
colouring, and soon captured his audience in a
friendly manner that befitted a media professional educator.
As I’ve often stated, it is
good sometimes to be
reminded of the basics,
safety criteria and practices, and
Marc did this in such a subtle manner.
One of the noticeable differences
about his tools was the highly polished finish on them, and prior to the
turning part of the demonstration, he
revealed his secret.
He had turned a round piece of MDF
with a 68mm recess to enable it to be
fitted to the chuck, then, reversing
the lathe, at slow speed, coated the
edge with burnishing compound, and
honed his tools using the MDF as
part abrasive! Simple and cheap!
(I’ve got some MDF should anyone
need some).(When I made mine, I
also faced it using some thin but firm
sponge (ex sports mat!) against
which I could hold bowls etc to remove the foot-two aids for one!!)
(I once read a very scientific study
carried out by two American turners(Alan Lacer, Gerry Glazer) - one an
4
academic and the other a grinding
specialist that proved the more
honed/polished the tool, the better
and finer the cut and the wood finish – see summary on
http://woodturninglearn.net/articles/
honingturningtools.htm)
As his wall thickness is about 3mm,
he uses the “inside out “ methodshaping the inside first, then using a
bright light inside, turn the outside
to get an even “lampshade” effect
(Lights available from Lidl, Argos
etc-see internet). He also used a
small magnetic low voltage LED
light on the tool rest to illuminate
shadow free the “work area” of the
tool. (His were from Woodart Products-07770 226640
www.woodart-products.co.uk)
Having mounted his blank onto a
screw chuck, he used a simple jig
to give the diameter of his mounting spigot-a piece of square section
pine, with a woodscrew on the end
for more illustrated and detailed
steps.)
For his second half, Mark chose a
lidded bowl, forming the outside first
before reversing to form the outside
of the lid, all on the
same blank. After
separating bowl
from lid, using a
thin parting tool, the
bowl was hollowed
initially using a
groove to prevent
the tool sliding
when presented.
With bevel rubbing,
sliding handle with
heel rubbing, swinging handle and rolling tool he sized the
lip to fit the lid.
Jamming the lid to
the bowl, he
skimmed it and removed the lid spigot
Above - a selection of some of the beautifully-crafted with gouge then
pieces by Mark Sanger
scraper.
His first act was to form a small
After drilling the hole in the lid, then
hole with a long small spindle
using a cone centre, the whole assemgouge, and measure the required
bly was remounted onto the MDF
depth then pushing in, twisting to
pad, the recess removed from the
10 o’c using his pull cut, began hol- base with a skew, and the base
lowing. The initial angle of his
formed.
push/pull cut was to stand in front
This was a much appreciated presenof the blank, and present tool on its tation by Mark, and I am sure we will
back,level, then lower to 45degrees, soon see some of his tips in 3D soon.
move to the right 45 degrees, then
twist handle 45 degrees, and then
********
adjust according to required cutusually about 2 o/c. Having opened Mantras of Maintenance
up the mouth of the vessel, he then Some (more) words of wisdom from
used his shielded hollowing ring
Ray Mellett
tool, with the ring protector “tight”.
The proviso was -“get it wrong and
n my many years of experiyou are in trouble!” Working from
ence in the industrial engithe rim down the vessel, then finneering sector, I’ve heard all
ished off the bottom with the
burred shear scraper. He advocated sorts of excuses and myths for
using a homemade mixture of
non conformances, a posh p.c
50/50 wax and foodsafe oil when
way of saying “it’s broken”.
sanding-keeps dust down and
So, in order to dispel a few of
sludge fills pores. (When tidying
up, he reminded us that a tool catch these, I offer my collection of
“words of wisdom”, gathered
is a texturing technique!!) See
Marks article-“Designing and mak- from others far wiser than I,
ing basic hollow forms-part 1 in
for your consideration.
Woodturning No. 264-March 2014
5
as a centre point, and a hole just big
enough to take a pencil at the appropriate radius. Having then
formed his foot, he remounted his
blank ready to begin the hollowing.
I
If the cause appears to
be obvious, it ain’t!
Look elsewhere.
There is nothing more
deceptive than an obvious fact (Arthur Conan
Doyle-The Boscombe
Valley Mystery)
If you have eliminated
all of the likely causes,
then it is the unlikely
ones that are to blame.
When you have excluded the impossible,
whatever remains,
however improbable,
must be the truth.
(Arthur Conan Doyle)
If it can’t happen, then
it will.
It’s a certainty that any
uncertainty is certain.
The probability of an
event increases in proportion to the improbability. (Arthur Conan
Doyle)
Near enough is never
near enough.
Make do and mend
never makes do.
If you believe “it won’t
happen to me” – It will.
Hence, prevention is always
better than cure, saving
down time, effort, cost and
frustration!
********
Cover photo
Kevin Daniels’ tool-grinding jig
More details in February’s
Woodturning magazine
Recognition for a talented ABWT Club member
Photo by Kevin Daniels
It is always gratifying when the work of club members becomes known beyond the confines of the club boundaries, but the hurdle for recognition by what is arguably one of
the UK’s most widely-read woodturning journals is set so high that it is only a selected
few who will ever be featured in its pages.
However, ABWT club member Kevin Daniels (above) has done just that with an “In the
Workshop” profile featured in the latest edition of Woodturning.
The 450 mm high laburnum vase, an engagement present to his daughter and son-in-law,
and a pen in holm oak,
made for Kevin’s friend
Zara, who was recovering
from an operation are but
two of the pieces featured in the profile.
Kevin also has strong views
about lathe safety, in particular the apparent reluctance of manufacturers to
incorporate in their otherwise sophisticated speed
controls a safety feature which would automatically prevent a lathe from being switched on at a
high-speed setting. Not much to ask, surely?
Photo by Pete Davis
Photo by Pete Davis
The full profile can be read in the February edition of Woodturning.
manently into our acrylic blanks fortunately we all managed to avoid
By Helen Woodward
that particular pitfall.
We eventually
discovered that
n Novemthe superglue is
ber last
used to achieve an
year a pen
incredible glassmaking course
like finish over
the wood blank.
was arranged
The acrylic was
at the Mill for
turned with the
club members.
aid of an old
It was run by
toothbrush to reBrian Chislett,
move the curly
Max Carey
swarf. It was then
sanded / polished
Trust member
with 12,000 grit –
and member of
yes 12 thousand
the Internagrit - used wet.
tional AssociaThis gave the
tion of
acrylic surface a
Pen-turners.
mirror like finish.
Both of the blanks
We started off with the usual cuppa that we started with were transand a quick natter. It was nice to see formed into rather nice pens by the
a mix of the Tuesday and Wednes- end of the session.
day folk, and I was rather happy to
see a pal and his shiny new motor- It was a very enjoyable day and has
cycle, a Triumph (of course!).
inspired several of the group to hit the
This was quickly followed by Brian Axminster website for supplies to
providing an interesting introducturn quite a few more pens. Several
tion to the art of pen turning. His
family members are fed up with
delivery style is very amusing bowls and are glad for a change of
populated with several ‘how-not-to- Christmas gift. Personally, it makes
do-it’ anecdotes.
the end-of-year presents for my chilOne of the most important decisions of the day
was the identification of
a responsible adult to be
in charge of the superglue de-bonding agent,
an important appointment as we would be
using a lot of the stuff.
It’s known as ‘stupidglue’ in our house for obvious readren’s teachers an easier choice!
sons. Ironically, none of the
superglue would actually be used
A very educational and fun experifor gluing things together - we used ence, so many thanks to those who
epoxy resin for that!
organised the course.
We were each provided with the
Special thanks to Brian for his expert
necessary equipment, primarily a
tuition and his patience with us all –
pen mandrel and two pen blanks.
and a thank you to John for being the
One blank was wood and one a
nominated “responsible adult” in
rather colourful acrylic.
charge of the de-bonding agent!
The morning flew by with us all
trying not to melt the drill bit per******
Pen-Making at the Mill
I
The Odd Spot 1
How often do you check the batteries in your remote controls, torches
etc? I’m always going on about it at
home but this time I was caught
out. Fortunately no harm was done
but as Ray reminds us elsewhere in
this edition, “prevention is better
than cure”and had I heeded that
warning I wouldn’t have had a to
spend a quarter of an hour or so in
cleaning out the mess.
Odd Spot 2.
Quite by chance I recently made the
startling discovery that a wellknown manufacturer of beef tea
drinks has come up with a novel
idea which no doubt is aimed at
increasing sales of its product.
Not only can it be used to make a
tasty drink but it also can double as
one of those tools that no engineer
can do without.
So, top marks tor Oxo’s marketing
team for bringing us an EDIBLE
VEE BLOCK
Ed
Last month’s competition results
A
lthough it’s probably true to say that we indulge in
our chosen hobby mostly for the pleasure it brings
us during the process of designing, creating and finally
realising our ideas, it is also very gratifying when our
work is appreciated by others, especially when those
“others” have some knowledge of the skill needed to
produce the finished article. In other words, a bit of recognition by our peers is (nearly!) always welcome, and
the hope that such recognition will come our way is one
reason why we enter competitions. Conversely, one of
the good things about competitions is that they do provide a stimulus for those of us who might be finding it
difficult to think of new challenges.
The theme for last month’s competition was “Any item
turned between centres” - a pretty broad brief, if ever
there was one, with seemingly little to stimulate the imagination. But Harry Childs was able to think “outside
the box” by producing this
month’s winning piece in the
Advanced section. So congratulations and thanks to Harry thanks because his innovative
work might just have given one
or two of us some food for
thought.
Congratulations too to the joint winners, Phil Patrick and Ian
Trevitt, in the Intermediate class. And how good to see that
Ian is now once again back at the lathe after his recent illness.
Read the rules!
There can be nothing more disappointing than discovering
that your carefully-crafted piece has been disqualified because
it failed to satisfy the criteria set down. So, to avoid any embarrassment to both yourself and the competition organisers,
do please ensure that your entry complies.
My thanks to John Ruffle for adding to his
task-load for the evening by providing the
photographs of the competition pieces. I will
endeavour to ensure that my next year’s flu jab
is the right one.
Ed
EQUAL ENDED OVAL
By Dave Smith
F
ollowing our last A&B Woodturning club night & my article in ‘Turnings’ regarding the development of an Egg Shaped Oval several club members have said
‘thanks for the info’.
However two members asked about an Equal ended shaped Oval.
I have shaken the old grey matter and here is my development of an Equal Ended
Oval.
Using only basic geometry skills, you
will need to be fairly accurate with
your construction
Method
Draw a Line A – B equal in length to
the long diameter of the oval.
Bisect this line & draw a line at 90
degrees to A – B
Point O the intersection
From O mark C – D equal to the small
diameter of your oval.
From A mark off point E equal to C
D.
Divide E - B into three (3) equal parts.
Now set your compasses equal to two (2) parts. & with centre O
mark off points Q 1 & Q 2
With your compasses set to length Q - Q from point O mark points P 1 & P2.
Set your compasses to P – C & using point P describe the large arcs.
With compasses set to Q – B using point Q describe the small arcs.
Thanks to Dave for his two interesting articles and thanks too to those members who responded to Dave. This is
what our newsletter is for so please, if you feel that you would like to comment on anything on these pages do
please get in touch with the editor on [email protected]
Just a thought - does anyone know WHY an egg is the shape that it is?
Ed
SEEING IS BELIEVING, UNFORTUNATELY AN INTRODUCTION TO DUST CONTROL - PART 1
By Ray Mellett
“M
ake sure you strip
off, and be sure to
give it a good
shake!”. Yes, this time, it is your
greeting from “SWMBO”(John Mortimer), on returning from your workshop.
Dutifully obeying, (the theory is you
eat better if you do what you are
told!), you remove your smock, only
to find yet more shavings and dust hits
the floor, especially on undoing the
Velcro around the neck and sleeves.
Then a casual frisk sends yet more to
the floor. You then realise that wearing that fleece whilst turning, although
it keeps you warm, was not the best
idea. A quick visit to the toilet reveals
yet more chips and shavings released
onto the floor from places you never
thought possible! A quick glance in
the mirror reveals a fine deposit on the
glasses, especially if plastic, due to the
static attracting the finer airborne particles. Having made yourself (externally) presentable and clean, you
dutifully enter the domestic parts of
the house, still itching slightly, which
does not go unnoticed. Like Wesley
in “Last of the Summer Wine”, you
are then told, “You can’t sit down like
that,” so you return to the bathroom
for a quick shower. Undressing, you
finally release the last of the hidden
particles that somehow got where you
didn’t think possible amongst the “unmentionables”, and then you notice
them around the shower outlet as you
step out. Feeling clean and virtuous,
you finally re-appear all polished and
wood-free at last, feeling just great.
If this is a scenario familiar to you,
read on. If it is not, I would suggest
you ain’t done much turning yet! That
great feeling after the shower means
you are clean on the outside, but this
is lulling you into a false sense of security, little do you know - it ain’t
necessarily so!!
Wood is toxic to various degrees, and
the resultant wood dust can do a lot of
damage to us poor morsels, especially
us older ones! Having suffered from
asthma some years ago, and experiencing some breathing problems when
turning, I recently discovered that like
Nick, I am also allergic to yew! So I
wanted to learn more, and hence apply
my academic training to do some more
extensive research to improve my lot. As
one of my managers once observed
“Things ain’t quite so bad until you look
into them!” So here is the result of that
research for your information.
If you think it is a more modern problem
you would be wrong . Pliny the Elder, in
his “Naturalis Historia,”ca. 77 AD,
wrote:- “Not to omit any one of them,
the yew is similar to these other trees in
general appearance . . . It is an ascertained fact that travellers’ vessels, made
in Gaul of this wood, for the purpose of
holding wine, have caused the death of
those who used them.” Wot, no foodsafe finishes? These dusts can cause irritation of our skin, and dermatitis. Breathing it in can cause a runny nose (rhinitis),
bleeds, and even nasal cancer. On our
bodies, it can cause skin irritation, dermatitis, nausea, even drowsiness. It gets
into our lungs, and in the Alveolar region
of our lungs where the dust clogs them
up,as 10-15% of those 0.5µm and belowsized particles are deposited, and can
stay for many days, even months, especially some hardwoods as it will not rot
down. As we get older, our respiratory
system gets less elastic, so this can lead
to shortage of breath, which results in
more lethargy, loss of memory, and
headaches. (Check your peak breathing
flow occasionally to check this - I was
OK at my recent check up at over 450
l/min) Our eyes can water. They also get
sore and can even get conjunctivitis.
(Rubbing them makes it worse!) According to the American Occupational
Safety and Health Administration (OSHA), “wood dust becomes a potential
health problem when wood particles
from processes such as sanding and cutting become airborne. Breathing these
particles may cause allergic respiratory
symptoms, mucosal and non-allergic respiratory symptoms, and cancer.” Our
breathing gets tight, we can wheeze, and
feel lethargic.There you have it, stated
bluntly. So if any of these problems are
yours, you should be concerned, and
need to read on. (Ref 6a) and take correc-
tive and preventative measures. To check the toxicity
of your chosen wood, see
Ref 2.
Having suffered myself
(unnecessarily,) I will attempt to explain in plain English a little of what we are up against. Since
“dust management” is a rather detailed
and complicated technical subject,
(both engineering and medically
speaking) this will be part 1, with the
rest to follow. As a result of my limited research on “wood dust”, I hope to
demystify its manifestation and effects
on our bodies, its generation, strategies to minimise/eliminate it and its
effects, and the various equipments on
the market such that you will be able
to assess your own situation and
choose the most appropriate for YOU.
I will in this part 1 attempt to explain
our “enemy”, albeit somewhat rather
academically, but also in terms you
can understand, and any statement
made justified with references, (given
at the end). This will enable you to
study the subject further should you so
desire, in order that you can make
your decisions based on fact rather the
usual “feeling in the water”
technique!(one of the principles of
quality!)
Using the advice given in that classic
“The Art Of war” by – Sun Tzu -i.e.
“If you know the enemy and know
yourself, you need not fear the result
of a hundred battles. If you know
yourself but not the enemy, for every
victory gained you will also suffer a
defeat. If you know neither the enemy nor yourself, you will succumb in
every battle,” I will try to acquaint
you with our “enemy”- dust - so you
too can be victorious, and enjoy turning without suffering afterwards from
the problems associated with respiratory, allergic or other forms of irritation listed above. I will also introduce
you to the language that is used and
hence help give you the tools and
knowledge such that you can
design/evaluate what
system/equipment suits you best in
defeating this enemy in your unique
workshop. Suitable equipment will be
analysed in part 2 (to follow).
You will all know or have been taught
that wood is like a big bundle of
straws, and to get the best finishes, we
have to slice through them in a smooth
cutting action. In the act of “cutting”,
the tip of the bevel on the tool first
slices /cuts into the wood, then the
bevel, acting as a wedge, (a bit like an
axe!) splits off the shaving before it
separates in a curl. It is that mechanical act of separation that causes the
initial dust. (This was plainly visible
at the Club meeting when the new
camera was at 27X zoom - you could
see the dust flying off!) As all those
microscopic tubes are made up of basic silicates, it is, in simple terms, similar to cutting a bunch of very fine
tubes of glass Therefore, the main
constituent of that dust is basically
very fine glass and other chemicals.
Nasty! And that is before we start
sanding!!
Now after you have finished your
turning stint, to sit and enjoy your
meal, (that’s where we came in!) you
might just wonder why you have
coughed a bit, sniffled, or your eyes
started to smart a little. (Ever tried
blowing your nose straight after turning, and seeing the muck that comes
out? Try it sometime if you are not
convinced) But you may appreciate
“why” better if you realise that during
a four-hour period in that workshop,
you will have breathed in some 660
gallons ( approx 3000 Ltr or 80 cubic
feet) of air, containing this dust. Dust
is defined as :- “solid particles, ranging in size from below 1 μm up to at
least 100 μm, which may be or become
airborne, depending on their origin,
physical characteristics and ambient
conditions.” (The medical profession
have many more than this!) Approximately 98-99% of all particles by
count are in the size range of 5 microns or smaller (usually referred to as
“small”) which tend to remain in suspension or settle out so slowly that
only quality electronic air cleaners and
HEPA (High Efficiency Particulate
Air ) cleaners are effective in removing these small yet dangerous particles
and are 99.97 % efficient
@0.3micron). You will now begin to
appreciate that it will not be easy, and
every solution is a compromise, with
you setting your own priorities. (Ref
3) This amount of air would contain at
least 170 million particles , 98% of
which are of 5 micron or less, most of
which will not have been exhaled
and will have to be dealt with by your
respiratory system-hence your slight
cough! (All figures are average and
approximate, Ref1). For a good diagrammatic explanation of our respiratory system, and how it copes with this
dust see Ref 4. To help you understand
the context, you may well ask “what’s a
micron?” Answer - It is one millionth
of a metre. For comparison, a human
hair is approximately 100 micron (100
µm) . The smallest dust particles we can
see glinting in the sun is about 50 µm. A
more comprehensive comparison chart
is given in Ref 2. BUT, if you can see
‘em, it is too late!! YOU ARE AT
RISK. (Ref 6) For an average workshop, in a modern one-car one-bike garage (6M x3M,approx 45 cubic M – or
1250 cubic feet) you will need air
changing ten times per hour for basic
filtration, as recommended by some of
the air room filter manufacturers (Ref
CAMVAC, MICROCLENE, Ref13). If
we adopt the OHSE legal limit of dust ,
(workplace exposure limits, or WELs)
of 5 mg/m3 (8-hour time-weighted average, total inhalable dust). then it should
contain no more than 225 mgr (approx
1/100 oz!) of dust! (Ref 4, & 7) .The
TUC contend that even this WEL is too
high (Ref 10) as 2 mg /M3 can be
harmful. And sanding generates about
100 times this amount! However, the
workshop is populated with equipment,
so the “free air” space is much less, and
hence the true concentration is greater.
But just think that two thimblefuls of
this fine dust will fail the WEL criteria
or hand sawing through just 7” of ¾"
wood will cause a two-car garage sized
workshop to fail these quality standards
This dust will also contain allergens.
Some allergens act on the skin, including many wood dusts, such as dogwood,
poison ivy, mahogany, pine, birch, poison oak, and beech, . and I would add
yew!!
There are some wood dusts which can
also be toxic if inhaled or ingested, for
example, East Indian satinwood, ipe,
South African boxwood. Wood toxins
are usually alkaloids. The two main respiratory diseases of allergic type caused
by occupational exposure to particles
are occupational asthma and extrinsic
allergic alveolitis. Occupational asthma
may be caused by certain wood dusts
(e.g., African maple, red cedar, oak, and
mahogany).” (Ref4) Spalted wood can
cause other additional problems, since
wood spores do not die. Last year a visitor to our demo lathes at Westonbirt
told me that after turning some spalted
wood, he became ill and had severe res-
piratory problems. The spores had
started to grow and multiply in his
lungs, resulting in a three month spell
in hospital! (For further details of
some of the problems caused see Ref
3 and Ref 4. From these facts alone,
you will by now begin to realise how
big our problem is, and how strong
our “enemy “has become. In a similar
vein to Sun Tzu, my old mate taught
me that the only way to beat deviousness is to be even more devious! In
modern “management speak” that now
equates to “Risk Management”
All risk assessment is based on the
probability of an event happening
multiplied by the effects if it did happen. (I often quoted to my students
Chernobyl as an example when the
maths took preference to common
sense!, Ref 8). When broken down
into small discrete sections as below,
the assessment becomes less formidable and easier to evaluate.
The sections are (Ref 9) :identify, characterize
1.
threats
2.
assess the vulnerability of critical assets to specific
threats
3.
determine the risk
(i.e. the expected likelihood
and consequences of specific
types of attacks on specific
assets)
4.
identify ways to reduce those risks
5.
prioritise risk reduction measures based on a strategy
6.
assess the vulnerability of critical assets to specific
threats
7.
identify ways to reduce those risks
8.
prioritise risk reduction measures based on a strategy
Adopting this, we have already
characterised and identified our
threat - ie, dust, established our
vulnerability and risk as 100%, so
all we have to do is identify ways
of eliminating or
shifting/reducing this risk and prioritising our solutions . Generally, if we can’t shift it, then we
must reduce it. So let us start at
the beginning, bearing in mind at
all times that the aim is to enable
us to breathe “clean air” whilst
turning. For the moment, we will
concentrate on the turning process,
where initially we generate large
shavings. (As I previously reported, Glen Lucas used to turn right
handed, but found the large (in
size and volume!) shavings caused
the back of his hand skin to be affected, so he went left handed!)
For the moment, as these shavings
are “large” and not airborne (for
long!) we will not be concerned
about them, but just let them fall
to the floor. The “finish cut” shavings, although much smaller, will
also be ignored for the moment.
As stated, the act of sanding generates more than 100 times the
WEL of 5mg/M3. IF we eliminated this, under the guise of “texturing”, our customers would not like
it! As they prefer “a nice bottom”
with a finish smoother than the
proverbial “baby’s bottom”, a là
Doug, we will have to take other
evasive actions. The act of sanding on the lathe means that “it” is
revolving, and the centrifugal
force, proportional to the speed,
and diameter, spins the dust generated out in a peripheral pattern.
Sanding from the top (a bad practice, easy to get into too!) means
the dust is directed straight at you
and into your breathing area.(You
may as well sniff it as snuff!)
Underneath takes it away from
you, and although not directly into
your immediate breathing area, it
is still in the atmosphere and in the
flow generated by the chuck, acting as a centrifugal fan, so it will
get there sooner or later! Many
years ago, I read an article by Tobias Kaye advocating “Wet Sanding”, using water spray or
finishing oil (be careful to spread
out your oily cloth outside afterwards to prevent instantaneous
combustion). But eventually you
will have to do some “dry” sanding so we cannot ignore it - the
problem will not go away! Turning down the speed will mean that
a smaller volume of dust per
minute will be generated, and will
not be spun out so fast or so far.
BUT IT IS STILL DUST.
Now, and this is going to hurt you just ask SWMBO how she manages
the household dusting, since the average household generates about 1
lb of dust a week! Thinking about it,
she “collects” with a brush or duster, ”conveys “ it by wrapping it up
in the duster before leaving the site,
or takes the dustpan and then “contains” it by placing the pan contents
into the dustbin, or shaking out the
duster into the bin.) However, this is
dealing with static dust, whereas we
are faced with moving dust, which
poses other problems. Nevertheless,
we also have to “collect, convey and
contain.” So now you have been
shown what to do, JUST DO IT - no
argument! You will have to admit it
- SWMBO is correct, this time!
However, whilst the principle is the
same, the practice will differ, as I
will explain.
with the task ahead and better understand Part 2. Watch this space.
That I will leave until next time,
hopefully explaining some more
terms used and the basic calculations you will need to make, and
what you need to know in order to
evaluate and compare, then sort out
the alternative solutions to suit
YOU. In the meantime, get to know
your own workshop in preparation
for the calculations to follow, measure it, calculate the volume (in cubic
feet and cubic metres), sort out
where you have possible space
available, of about 3ft x 3ft x 5 ft
(1M x1M x!.5M) and wall/ceiling
space 3ft x2ft x1ft . Alternatively,
you could procrastinate and do
nothing. Spring cleaning is on the
cards, so bear these space envelops
in mind! As you will appreciate, in
our magazine I can only touch on
the basics of this very technical subject, to make you aware, and point
you to other sources of information.
Meanwhile, if you read these references, you will be well acquainted
http://www.hse.gov.uk/pubns/wis23.
htm
Ref 12
http://www.woodworkerssource.co
m/toxicity_list.php
Ref 13
REFERENCES AND FURTHER READING
Ref1
http://www.normalbreathing.com/in
dex-nb.php
Ref 2
www.trane.com/.../IAQ%20for%20
High%20Performance%20Build
in...(
Ref
3http://www.hse.gov.uk/woodworki
ng/wood-dust-exposure.htm see
video
Ref4
www.who.int/occupational_health/...
/en/oehairbornedust3.pdf
Ref 5
http://www.peakpureair.com/particl
es-and-their-sizes-microns
Ref 6 Dust Facts
dustlesstools.com/pdf/DustFacts.pdf
We all know that if something is
Ref 7 Woodworking Sheet No 30
moving, in order to catch it, the
(Revision 1) HSE Toxic Woods.
“catcher” will have to move faster!
Ref 8
As the dust is suspended in the air,
http://www.hse.gov.uk/risk/theor
what better medium to use than air?
y/alarpglance.htm
It is fairly easy to get to move (con- Ref 9 ISO 31000 Risk Managevey), to direct and control and it is
ment-Standard.
versatile in that it can carry (convey) Ref 10
most solids, then all we have to do
www.tuc.org.uk/workplace/tucis “contain” (trap) it . But how?
19972-f0.cfm
Therein lays the problem for our
Ref 11
workshop.
6
http://www.airclean.co.uk/TechnicalBulleti
ns.htm
Ray submitted both Part 1 and Part 2
together but I thought it best to delay
publication of the second part until
next month to give us time to absorb
the information, not to mention the
implications of what he has written.
I’m sure that most members will already be aware of the unpleasant effects of wood-dust but Ray’s detailed
explanation, backed up by the findings
of scientific studies it will make us
look more carefully at our own workplace environments. And if in the
process, SWMBO is also appeased we
will indeed have achieved something
well worthwhile.
Ed
How Many “Ss” in “Tools”?
By Ray Mellett
M
ost of you will, I suspect reply “one”, but you’d be
wrong-there are in fact three, as
Tim, a professional Tutor from
Stroud College, who used to teach
us at the Mill in the old days with
John May, Melita, etc. taught us. He
was also a supporter of the Frans
Brown theory- “you will never
make a turner as long as……etc etc
if you can’t sharpen your tools!”
Once he had us all bring in our own
grinders etc and on a one-to-one basis, ensured we all knew about the
different types available, wheels and
grades and techniques and that we
could apply them. As Bob reminded
us in his thoughts on tool sharpening last month, it’s a minefield for a
lot of turners, so if you are starting
out, study the field, take advice, and
then practise using your grinder.
Most tools come with the grind that
suits the producer, rather than the
user, so the first task is to SHAPE
the tool to your requirements. As
Bob stated, this tends to clog up the
wheels with the metal particles. This
is the stage at which you can ruin
your wheel by thinking you have to
apply more pressure, and failing to
spread the area of contact across the
whole width of the wheel, moving
from left to right and returning
whilst at the same time rolling the
tool as appropriate, using light pressure. Failure to do so results in the
inevitable groove in the centre of
the wheel, and a heavy deposit of
steel bits onto the surface, causing a
loss of grinding capacity and excess
heat being generated in the tool.
The edge is sharp when the
sparks also come off the inside of
the gouge / tool (i.e. the side facing
you). As with turning, it requires
little pressure, and the wheel will
“talk” to you if you get too enthusiastic. Further grinding will only remove extra metal and shorten your
tool unnecessarily. Remember, met-
al removed, from both tool and stone,
is equal to money taken from your
pocket!
This shaping leaves a very rough finish on the edge, so the next stage is to
SHARPEN your tool. This requires a
smaller (i.e. higher) grit wheel, and a
lighter touch.
Then comes the final stage SMOOTH or SHINE the finish,
sometimes called linishing, burnishing or polishing. We all know a sharp
tool cuts much better and leaves a better finish. This has been proven scientifically by Alan Lacer (see
http://woodturninglearn.net/articles/h
oningturningtools.htm). Note also
what he says about Frank Pain 's The
Practical Woodturner, as below:In that book he states: "At the works
where we could turn 2 gross of chair
legs a day, probably four or five tools
would be used and they would be
ground once a day. Some work of
course might call for more frequent
grinding, whereas for some beech
jobs they might last for days."
So to turn nearly 300 chair legs with
only one sharpening means he must
have had a good sharpening technique! Think how many times you
would visit the grinder if so doing!
And he only had carbon steel tools,
not HTS!
The use of hand held or jig sharpening
is your choice, but whilst some of the
jigs are rather expensive, they do guarantee consistency and also have the
advantage that very little metal is removed at each visit!. IF you use one,
take a tip from Tim - he used to mark
all his tools with the settings he used
on the jig so he could easily replicate
that setting next time he wanted to
touch it up. To ensure you remove the
minimum of metal, mark the tool tip
with a felt tipped pen, then adjust settings to just “kiss” the edge by applying the tool to the stationary wheel,
7
rotating the wheel by hand to check
the chosen setting just caresses the
tip of the tool. For a reasonable price,
about £30/40, Aldi and Lidl offer a
very
useful
grinder/belt
sander/linisher , which, with the addition of a few MDF jigs, makes the
equivalent of a very expensive model
on the market. The belt can give a
good smooth linished finish to the
cutting edge. However, I will re emphasise Bob’s warning regarding
those sparks and the fire hazard. DO
NOT SHARPEN WHILE WEARING A FLEECE-I’ve got the burn
holes to remind me!
Remember always to allow the
wheel to come to rest before switching it on again, and never grind on
the side of the wheel. As Bob reminds us, safety glasses and a full
face mask is a must-an exploding
wheel is not a pretty sight!!(And you
risk losing yours in the process Ed)
For more detailed information, a
very good guide to grinding wheels,
their uses, and how to choose the
one for you, is given at
http://www.mmsonline.com/articles/
choosing-the-right-grindingShould you feel you would like further advice or training, see
http://abrasivewheeltraining.com/ne
wbookings.php?town=Bristol for
example.
Likewise, never be tempted to “just”
kiss that lathe toolrest on the sander
belt - those sparks can set the residual sawdust smouldering, which can
then later burst into flames after
you’ve left the workshop!
(I do have my H&S certificate for
Abrasive Wheels-Mounting, Setting
and Safe Operation!).
*********
Club events calendar
Venue - St Teresa’s,
Filton @ 7.30 pm
unless otherwise
stated
Monthly themes
(Advanced and
Intermediate single
theme)
Event
Deadline for
articles in
Turnings
2015
Reminder - all meetings now held on Mondays until April when we revert to Thursdays again,
dates to be advised
16th February
Mark Baker
16th March
Hands - On
20th April
TBA
AGM and member demo Any turned item
Mary Ashton
Bowl, max diameter 6”
[152mm]
“Easter”
A toy
30th January
27th February
3rd April
TBA
As members will now know, Mark
Baker’s visit to the club has been
brought forward to the February
evening and the Hands-On event
takes place on 16 March
th
USEFUL CONTACTS
Club website
www.avon-and-bristol-woodturners.org.uk
Club email
[email protected]
Secretary
[email protected]
Turnings Editor
Mike Openshaw - 41 Tyler Close, Hanham, Bristol, BS15 9NG
01179 607266
email: [email protected]
8