masking materials for preventing hot -dip galvanizing

Transcription

MASKING MATERIALS
FOR PREVENTING
HOT-DIP GALVANIZING
BY BERNARDO DURAN, III AND THOMAS LANGILL, PHD
BACKGROUND
threads when precise fit is necessary and
Masking materials, also called stop-off
the additional width of the galvanized
materials, are products applied to steel in
coating would cause fit issues. Another
specific
reason to mask steel is to give a higher
areas
galvanizing
to
prior
prevent
to
zinc
hot-dip
from
slip factor on some faying surfaces.
reacting with and adhering to the steel.
Many different types of products have
Masking is done for a myriad of reasons.
been used as masking materials. Some
For example, sometimes it is preferable
products are specifically designed for the
to prevent galvanizing on large areas of
purpose of preventing galvanizing, and
steel that will be welded, rather than
other products from other industries or
removing the zinc coating later. Masking
for other uses have been found to work
materials are also sometimes applied to
Copyright © 2010 American Galvanizers Association. The material provided herein has been developed to provide
accurate and authoritative information about after-fabrication hot-dip galvanized steel. This material provides general
information only and is not intended as a substitute for competent professional examination and verification as to
suitability and applicability. The information provided herein is not intended as a representation or warranty on the part
of the AGA. Anyone making use of this information assumes all liability arising from such use.
Protecting Steel for Generations
1
well
at
masking
steel
prior
availablility and recommendations from
to
AGA members.
galvanizing.
INTRODUCTION
The study consists of two phases. The
An American Galvanizers Association
goal of Phase 1 testing is to determine
(AGA)
to
the effectiveness of the various masking
determine the effectiveness of masking
products in masking the steel surface
materials at preventing adhesion of zinc
from zinc. The products that successfully
to steel during galvanizing.
masked steel in Phase 1 were included in
study
was
conducted
Phase 2 testing. The goal of Phase 2 is to
This study is important because masking
determine
materials are commonly used, and until
successful materials from Phase 1 testing
now, there was no definitive study that
when
looked at the efficacy of various
Attempting
products used to prevent galvanizing.
appearance of the steel (by chemical
the
given
to
performance
shorter
restore
of
cure
the
the
times.
original
cleaning) is also a goal in Phase 2.
The information obtained in this study
will give galvanizers and fabricators
The masking materials were tested on
detailed facts on the performance of
three different types of surfaces; flat
various masking materials, as well as
plate, buried threaded holes, and bolt
provide data on application and removal
threads. Two types of flat plate were
of the masking materials after hot-dip
used in the study. The first type of flat
galvanizing.
plate (see Figure 1, next page) was
approximately 3” x 6”. The masking
TEST PROCEDURE
materials were applied to the steel away
In this study 15 masking materials were
from the hole. The masking area had a
tested. Some of these materials are
width of 3” and a length of a little less
currently used to mask steel, and others
than 4”.
have been used in the past with some
success. In addition to past performance,
All masking materials were applied to
the products were chosen based on their
the steel prior to the cleaning steps of the
2
the
Some of the plates were drilled and
masking materials were subjected to a
tapped to provide a plate with a buried
caustic bath, pickling bath, and flux
threaded hole to test the masking
bath. It was important to determine if the
materials (see Figure 2). The buried
masking materials could survive the
threaded holes were 2½” deep holes
cleaning chemicals, because if they
drilled into a 3” thick plate (see Figure
could survive, the masking materials
2). Buried threaded holes were used only
could be applied at the fabricator’s
in Phase 1 testing. The bolts used in the
facility, and thereby save the galvanizer
study
the time and trouble of applying the
approximately 2 ½” in length (see
materials.
Figure 3).
galvanizing
process,
meaning
were
¾”
in
diameter
and
Figure 1: Flat Plate
Figure 3: Coated Bolt Threads
The masking materials were applied to
the plates with a foam brush and then
spread in the masked areas until an even
consistency was achieved.
For the buried threaded holes the
masking products were simply poured or
squeezed into the holes.
Figure 2: Buried Threaded Holes Plate
For the bolt threads, the masking
materials were applied by either dipping
3
the bolts directly into the bottle of the
•
Duct Tape
material, if there was enough room, or
•
Kapton Tape
spread onto the threads using a foam
•
VHT Header Paint (tested only
brush. The material was spread onto the
on flat plate)
threads to achieve even thickness.
•
Dow Corning Compound #111
•
DAP
The masking materials for all surface
Household
Adhesive
Sealant
types were applied prior to the chemical
•
Stop Galv
cleaning
galvanizing
•
NAPA RTV Red
process. This ensured the masking
•
GE 100% Silicone Caulk
materials could stand up to the cleaning
•
Galva Stop
agents and would remain on the steel
•
Valmont Masking Compound
prior to galvanizing.
•
Macropoxy 846
•
3M High Temperature
steps
of
the
Masking products were removed by
using
a
metal-bristled
brush.
Aluminum Tape
The
materials were scrubbed off the surface
and then compressed air was used to
blow off the debris. In Phase 2 testing,
•
Maskote Zinc Stop-Off
•
ZYP Boron Nitride Lubricoat
•
ZYP Boron Nitride Hardcoat
scrubbing the cleaned steel with a nylon
Determining the effectiveness of each
bristled brush and Simple Green solution
masking
was also performed to determine if the
material
came
down
to
observing how much of the masked area
original steel finish could be restored. A
galvanized. The smaller the area that
grinder was also tested in Phase 2 for
galvanized, the more effective the
removing the materials on flat plate.
masking material.
PHASE 1 TESTING
For flat plate, greater than 90% of the
MASKING MATERIAL TESTING
masked area had to remain ungalvanized
Fifteen different masking materials were
to proceed to Phase 2 testing. For buried
tested in Phase 1, including:
threaded
holes,
4
almost
the
entire
threaded area needed to remain free of
Six products successfully prevented zinc
galvanizing. If a few small spots of zinc
coating on the buried threaded holes,
were observed, the masking material was
including:
still considered effective. For bolt
•
threads, the same criteria applied as that
DAP
Household
Adhesive
Sealant
for buried threaded holes – almost the
•
entire
•
•
•
Macropoxy 846
•
threaded
area
must
remain
ungalvanized to be considered effective.
TEST 1 RESULTS
On the flat plate, nine products failed to
prevent galvanizing on a minimum of
Six of the 14 products failed to prevent
90% of the masked area. Six products
galvanizing
successfully prevented zinc coating a
masking materials that did prevent zinc
minimum of 90% of the masked area on
coating on bolt threads include:
flat plates including:
on
•
Galva Stop
bolt
threads.
•
Stop Galv
•
Stop Galv
•
•
DAP
•
NAPA RTV Red
•
Galva Stop
•
NAPA RTV Red
•
•
•
•
Macropoxy 846
•
Household
The
Adhesive
Sealant
Only 14 of the masking materials were
tested on buried threaded holes and bolt
The
threads. The VHT Header Paint was not
bolts
masked
with
Valmont
Masking Compound were lost during the
tested because paint cannot be easily
galvanizing process during testing.
removed from threaded areas.
For more detailed information on how
Eight products failed to prevent zinc
each masking material performed on the
coating on the buried threaded holes.
various surface types, and application
5
and removal data, please see the charts
manufactures
in Appendix 1.
achieve optimum performance.
PHASE 2 TESTING
The second goal of Phase 2 testing was
curing
instructions
to
SHORTER CURE TIME TESTING
to determine if the original steel finish
AND CLEANING
could be restored after removing the
The first goal of Phase 2 testing was to
determine
how
the
products
masking materials from the steel.
that
performed well in Phase 1 testing
The
performed were applied using shorter
effectiveness of these masking materials
cure times. Products tested in Phase 2
in Phase 2 testing was the same as in
included:
Phase 1 Testing. Ninety percent or more
•
Stop Galv
of the masked area on plates had to
•
Galva Stop
remain free of galvanizing to be
•
considered successful. For bolts, only a
•
NAPA RTV Red
few small areas of zinc on the masked
•
threads were allowed for the material to
•
DAP
be considered successful.
Household
Adhesive
criteria
for
determining
the
Sealant
For the flat plate specimens, each
Although Valmont Masking Compound
masking material was applied to the
did well in Phase 1 testing, it was not
same areas used in Phase 1 testing. The
included in Phase 2 testing. Also, as
plates had been stripped of all zinc and
mentioned earlier, buried threaded holes
remaining residues from Phase 1 testing.
were not tested in Phase 2.
Masking products were applied to only
one side of the plates to decrease
Shorter cure times were tested in Phase
application time. Cure times included 1
2. These tests demonstrated the limits of
and 2 hours for flat plate specimens.
the masking materials. However, it is
important to note these materials should
For bolt threads, the masking materials
be
were applied to the same bolts as those
used
in
accordance
with
the
6
used in Phase 1 Testing. The bolts had
TEST 2 RESULTS
been stripped of all galvanizing and
FLAT PLATE
debris from the Phase 1 tests. Three
For the 1 and 2 hour cure times only
different cure times were tested on the
Stop
bolt threads; 30 minutes, 1 hour, and 2
successful at preventing galvanizing.
Galv
and
Galva
Stop
were
hours.
Some ashy material from Stop Galv and
For both the flat plate specimens and the
Galva Stop remained on the plates even
bolt thread areas, cleaning the baked on
after scrubbing with a metal-bristled
masking materials after galvanizing was
brush.
attempted by scraping the steel with a
Cleaning the plates with the Simple
metal-bristled brush and then scrubbing
Green solution had a negligible effect on
with a nylon brush and Simple Green
removing the debris left from the
solution (see Figure 4). The goal of
masking materials.
cleaning with the Simple Green solution
was to determine if the original finish of
Using a grinder to remove the baked-on
the steel could be restored after the
masking materials was excessive and is
various masking materials had baked on
not
the surface while going through the
immediately went through the masking
galvanizing process. Cleaning with a
materials
grinder was attempted on the flat plate
underneath.
recommended.
and
The
attacked
grinder
the
steel
specimens only.
BOLT THREADS
Three different cure times were tested
for each masking material on bolt
threads, including 30 minutes, 1 hour,
and 2 hours. For the 30 minute cure time
Galva Stop and NAPA RTV Red were
the only products that successfully
prevented galvanizing.
Figure 4: Simple Green and Nylon Brush
7
For the 1 hour cure time, five of the six
Cleaning with the Simple Green solution
masking materials were successful at
was done after the 1 hour curing time. If
preventing galvanizing, including Galva
the masking materials had been given
Stop, Maskote Zinc Stop-Off, DAP
their full recommended curing time it is
Household Adhesive Sealant, NAPA
likely the products would have been
RTV Red, and Stop Galv.
easier to remove and would have cleaned
even better.
For the 2 hour cure time all six masking
materials
successfully
prevented
Cleaning the masking materials from the
galvanizing on the bolt threads.
bolt threads with a grinder was not
After galvanizing, a metal-bristled brush
attempted because it would damage the
was used to scrape the big chunks of
threads.
baked-on masking material from the
threads. A Simple Green solution and
CONCLUSION
nylon brush were then used to remove
The goal of this study was to determine
the remaining baked-on debris. The
which commercially available masking
appearance of the bolt threads was
materials
improved for all the masking materials
galvanizing on masked areas.
work
best
at
preventing
after cleaning with the Simple Green
Six commercially available masking
solution.
materials were identified to successfully
The cleanest bolts were those masked
prevent galvanizing on one or more
with Maskote Zinc Stop-Off, GE 100%
surface types, including flat plate, bolt
Silicone Caulk, and DAP Household
threads, and buried threaded holes. The
Adhesive Sealant. It was necessary to
successful masking materials included
wash the bolts masked with NAPA RTV
(in no particular order):
Red twice because of the gummy
• Stop Galv
residue.
• GE 100% Silicone Caulk
Some
baked
on
masking
material remained on the bolts masked
• Maskote Zinc Stop-Off
with Galva Stop and Stop Galv.
• NAPA RTV Red
• (cont. on next page)
8
• Galva Stop
COSTS OF THE MASKING MATERIALS
• DAP Household Adhesive
The masking materials tested in this
study have a wide range in price, which
Sealant
can be found in Appendix 1. In addition
Additional and detailed performance
to the purchase price, additional costs to
data is presented in the charts in
be considered include labor time for
Appendix 1 and additional pictures are
applying and removing the materials.
presented in Appendix 2.
Detailed application and removal times
are included in the charts in Appendix 1.
SAFETY AND HEALTH INFORMATION
Material Safety Data Sheets (MSDS)
should be obtained and adhered to when
using
these
materials.
Necessary
personal protective equipment should be
employed when appropriate. Almost all
of
these
masking
materials
had
nauseating smells and should be used
only in well ventilated areas. It is
important to note some of these products
were not designed to be used in the
temperature ranges of the galvanizing
process.
9
Appendix 1.
Detailed Performance Data of Masking Materials
10
11
$4.75 / small tube
$170.00 / gal.
Valmont
Masking
Compound
ZYP Boron
Nitride Hardcoat
$120.00 / gal.
Maskote Zinc
Stop - Off
$45.00 / qt.
$89.78 /
gal. of Part A & B
Macropoxy 846
Stop Galv
$4.97 / 10.1 oz. tube
GE 100%
Silicone Caulk
$14.19 / 11 oz. tube
$0.35 / oz
$48.00 / liter
Galva Stop
NAPA RTV Red
$0.49 / oz
$3.98 / 2.8 oz. tube
DAP 100%
Silicone
Adhesive
$1.33 / oz
$0.37 / oz
$1.41 / oz
$1.29 / oz
$0.94 / oz
$1.42 / oz
$1.42 / oz
Price
Product
-
Yes
Yes
Yes
Yes
-
Yes
Yes
-
N/A
N/A
1 min.
5 mins.,
48 secs.
4 mins.,
26 secs.
2 mins.,
32 secs.
1 min.
1 min.
N/A
1 min.,
32 secs.
2 mins., 37
secs.
N/A
1 min.
2 mins.,
38 secs.
2 mins.,
21 secs.
1 min.,
22 secs.
N/A
N/A
Standardized
Application Removal
Success
Price
Time
Time
FLAT PLATE
Yes
Yes
-
-
Yes
Yes
Yes
-
Yes
Success
3 mins.,
24 secs.
10 mins.,
30 secs.
N/A
N/A
5 mins.,
13 secs.
32 mins.,
26 secs.
1 min.,
15 secs.
N/A
6 mins.,
30 secs.
Application
Time
7 mins.,
52 secs.
5 mins.,
28 secs.
N/A
N/A
3 mins.
8 mins.,
40 secs.
5 mins.,
18 secs.
N/A
12 mins., 5
secs.
Removal
Time
BURIED THREADED HOLES
-
-
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Success
PHASE 1 TESTING - OVERVIEW OF SUCCESSFUL MASKING MATERIALS
N/A
N/A
5 mins.
9 mins.,
45 secs.
5 mins.,
12 secs.
37 mins.,
10 secs.
10 mins.,
30 secs.
3 mins.
9 mins.,
30 secs.
Application
Time
BOLT THREADS
N/A
N/A
10 mins.,
20 secs.
4 mins.,
18 secs.
3 mins.,
5 secs.
1 min.,
11 secs.
7 mins.,
30 secs.
6 mins.,
50 secs.
4 mins.,
22 secs.
Removal
Time
12
Poured onto the surface and
spread with a foam paint brush.
32 mins., 14 secs.
(31/32 mins.
spent on prep
time for epoxy)
2 mins., 37 secs.
1 min., 32 secs.
4 mins., 26 secs.
2 mins., 32 secs.
1 hr., 33 mins.
3 mins., 48 secs.
4 mins., 16 secs.
Macropoxy 846
Maskote Zinc
Stop - Off
NAPA RTV Red
Stop Galv
Valmont Masking
Compound
VHT Header Paint
ZYP Boron Nitride
Hardcoat
ZYP Boron Nitride
Lubricoat
-
-
Applied 2 coats of paint. Allowed
for dry time between coats.
Two minutes of application time was to stir
the product. Poured onto the surface
and spread with a foam paint brush.
Poured onto the surface and spread with a foam
paint brush. Material had the runniness of paint
and was very messy. 3 minutes of the application
time was due to stirring the product like paint.
Yes
Poured the product on, spread with a foam paint
brush. Product went on thick and dried quickly.
Yes
Yes
Used a caulk gun, then spread using a foam
brush. Went on easy, but kind of thick.
Very thick, like a paste. Used a
foam brush to spread around.
Yes
Very runny - dries very quickly, making it hard to
spread around. Used a foam brush for spreading.
-
-
2 wraps. Tape did not stick well, much
harder to work with than the duct tape.
30 mins.
Kapton Tape
Yes
1 mins., 22 secs.
GE 100%
Silicone Caulk
Used a caulk gun, then spread using a
foam brush. Went on very thick.
2 mins., 21 secs.
Galva Stop
Yes
25 mins.
Duct Tape
-
Squirted the product onto plates, then spread
around with a foam paint brush. Material spread
easily, but was messy because it does not dry.
Shook can, poured, then spread
using a foam brush.
3 mins., 42 secs.
Dow Corning
Compound #111
-
Squirted the product onto plates, then
spread it with a foam paint brush.
Material was very easy to work with.
-
3 mins., 20 secs.
DAP Household
Adhesive Sealant
Almost
Masking
Success
Thoroughly ensured the edges were sealed.
Application Notes
Wrapped 2 times around plates.
17 mins., 26 secs.
Application
Time
3M High
Temperature
Aluminum Tape
Product
The entire area galvanized.
About 20% of the area galvanized.
All the plates galvanized
Entire area was completely
free of galvanizing.
Very slight seepage at perimeters.
Almost the entire area
remained free of galvanizing
Entire area was completely free
of galvanizing; very clean.
About 15% of the area galvanized
Less than 90% remained bare
The material prevented galvanizing,
but the surface was stained black.
Entire area was completely
free of galvanizing
Less than 90% remained bare
At least 80% of the area galvanized.
One plate galvanized completely
and the two other plates had
large areas that galvanized.
About 12% of the area
galvanized. Seepage at ends
caused galvanizing in those areas.
Notes
FLAT PLATE - PHASE 1 TESTING
N/A
2 mins., 32 secs.
N/A - product
failed completely.
1 min.
5 mins., 48 secs.
1 min.
1 min.
1 min.. 37 secs.
18 mins., 39 secs.
1 min.
2 mins., 38 secs.
10 mins., 52 secs.
40 secs.
2 mins., 11 secs.
9 mins., 24 secs.
Removal Time
N/A
The burned product adhered to the steel very well. I
had to score it with the edge of a flathead screwdriver
and then scrape it with a small metal-bristled brush.
N/A
Used big and small metal-bristled brushes
to scrape material off the metal.
Used a small metal-bristled brush to scrape the
material off. The material adhered to the surface
tenaciously, which required much harder scraping.
Used a big metal-bristled brush
to scrape away the material.
Used a big metal-bristled brush.
The material came off very easily.
Used a small metal-bristled brush
to scrape the material off.
Scored tape with a flathead screwdriver, then used a
metal-bristled brush to scrape away remaining debris.
Used big and small metal-bristled brushes to
scrape away the product. It came off fairly easily.
Used a small metal-bristled brush to scrape
since the big metal-brush was innefective. Had
to scrape very hard to get this material off.
Scraped off burnt tape with a metal-bristled
brush. Scraped off very easily.
Scraped with a small metal-bristled brush.
Scraped off with a small metal-bristled brush.
The material was very gummy and hard to remove.
Used a flathead screwdriver to scrape
the tape and then pulled it off.
Removal Notes
13
Balled up tape, then stuffed in the holes.
Poured into holes
3 mins.
5 mins.
2 mins.,
30 secs.
1 min.,
15 secs.
Dow Corning
Compound #111
Duct Tape
Galva Stop
GE 100%
Silicone Caulk
5 mins.,
13 secs.
1 min.
4 mins.
10 mins.,
30 secs.
N/A
3 mins.,
24 secs.
4 mins.,
16 secs.
Macropoxy 846
Maskote Zinc
Stop - Off
NAPA RTV Red
Stop Galv
Valmont Masking
Compound
VHT Header Paint
ZYP Boron Nitride
Hardcoat
ZYP Boron Nitride
Lubricoat
-
Yes
2 minutes of application time was due to
stirring product. Poured material into
the holes. Material dried fast.
3 minutes of application time was due
to stirring the product. Poured into holes.
N/A
Yes
-
-
Yes
Yes
N/A
Had to cut into the side of the roll, since an
industrial size caulk gun was not available.
Poured into holes.
Squirted into holes with a caulk gun
Poured into holes; runnier than Galva Stop or
Stop Galv. Dries faster than other products, too.
Preparation time for product took 31 minutes.
Poured into holes; very runny and messy.
32 mins.,
26 secs.
-
Slightly harder to work with than duct tape.
Balled up, then stuffed in the holes.
8 mins.
Kapton Tape
Yes
-
-
-
Squirted into holes w/ a caulk gun
Squeezed product out of tube and into holes. The
material was very hard to squeez out of the tubes.
Yes
Squeezed material out of tube and into
holes. Hardened like caulk, still flexible.
Material remained waxy after 14 hours.
6 mins.,
30 secs.
-
Masking
Success
Balled up tape, hammered it into
hole using a wooden dowel.
DAP 100%
Silicone Adhesive
Application Notes
9 mins.,
41 secs.
Application
Time
3M HIgh
Temperature
Aluminum Tape
Product
5 mins.,
40 secs.
N/A
7 mins.,
52 secs.
None of the holes galvanized, but
there was some frozen zinc inside
the holes that had to be wedged
out. Wedging out the zinc might not
always be possible for all fabrications.
All of the holes galvanized 100%.
N/A
5 mins.,
28 secs.
In addition to masking intended
areas, it caused bare spots
in surrounding areas.
N/A
Used a metal-bristled brush to scrub the
material out. Holes were charred black inside.
11 mins.,
30 secs.
1 of the 6 holes galvanized
N/A - all holes galvanized 100%.
Used flathead screwdriver to break apart hard ash, then
used small metal-bristled brush to scrape out the rest.
Some small particles remained inside the holes.
N/A
Used flathead screwdriver to break apart material, then used a
small metal-bristled brush to scrape out remaining material.
Used flathead screwdriver to pry out material, then used a small
metal-bristled brush to clean the rest of the material out.
5 mins.,
51 secs.
2 of the holes galvanized completely,
4 holes galvanized partially.
Used a small metal-bristled brush to clean material
out of the holes. Material came out very easily.
3 mins.
Used flathead screwdriver to break apart material inside the
holes. Material was extremely hard, required considerable
force. Used a small metal-bristled brush to scrape out rest of
the material, which also required considerable effort.
None of the holes galvanized.
Holes looked very clean.
8 mins.,
40 secs.
Used flat-head screwdriver to scrape out tape, then used a metalbristled brush to get the rest. Some unmasked areas around holes
did not galvanize, which could fail inspection after galvanizing.
5 mins.,
18 secs.
The very top of one hole galvanized
a tiny bit, but it could have been
an application error, as the hole
was not filled to the very top.
3 out of the 6 holes galvanized
Used flathead screwdriver to break apart material, then used a
small metal-bristled brush to scrape material out.
8 mins.,
26 secs.
In 5 of the 6 holes, a small
area galvanized. The area
was about 10% of the holes.
Used a metal-bristled brush to scrape
material out, which was very hard to do.
Scraped w/ metal-bristled brush. Some
unmasked areas around holes did not galvanize,
which could fail inspection after galvanizing.
6 mins.,
17 secs.
5 of the 6 holes galvanized
Scraped blob of material out with flat-head screwdriver. Used
a metal-bristled brush to scrape the rest of the material out.
Consistency of dry caulk. Some small crumbs remained.
Used flathead screwdriver and small,
metal-bristled brush to pry out the tape.
Removal Notes
Scraped product out with flat-head screwdriver.
Hard, flexible consistency like dry caulk.
12 mins.,
5 secs.
6 mins.,
17 secs.
Removal
Time
3 mins.,
50 secs.
4 out of 6 holes did galvanize
4 holes galvanized completely,
the other 2 had considerable
amounts of zinc in each.
Notes
BURIED THREADED HOLES - PHASE 1 TESTING
14
Yes
Squeezed material onto threads, smeared on w/
foam paint brush. Had wet, waxy feeling after drying.
Wrapped 5-6 times around each bolt.
Dipped bolts into bottle to apply material.
Hardened, but still flexible. Will stick to
itself if it touches other coated products.
Smeared material on w/a foam paint brush.
Somewhat easier to handle than NAPA RTV red.
N/A
8 mins.
5 mins., 30
secs.
3 mins.
10 mins., 30
secs.
6 mins., 30
secs.
Duct Tape
Galva Stop
GE 100%
Silicone Caulk
Kapton Tape
-
Not tested, as paint cannot be
easily removed after galvanizing.
N/A
4 mins., 5 secs.
5 mins., 14
secs.
VHT Header Paint
ZYP Boron Nitride
Hardcoat
ZYP Boron Nitride
Lubricoat
-
-
Goes on very thick, so it could get expensive.
Used a foam paint brush to spread around.
Need an industrial size caulk gun.
9 mins., 10
secs.
Valmont Masking
Compound
Three minutes of application time
was stirring the product. Dipped bolts
into masking material to apply.
Yes
Dipped bolts into bottle to apply material. Thicker
than Galva Stop. Hardened, but still flexible.
Sticks to itself if it touches other coated products.
5 mins.
Stop Galv
-
Yes
Smeared material on w/ a foam paint
brush. Applied thick in many areas
because of product consistency.
9 mins., 45
secs.
NAPA RTV Red
Three mins. of application time due to stirring.
Dipped bolts into material. Dries very fast.
Yes
Very runny, hard to smear around. Rather
than smearing, it dries, lumps up, and comes
off the metal. Very strong, nauseating
smell - similar to nail polish remover.
Maskote Zinc
Stop - Off
5 mins., 12
secs.
Macropoxy 846
Yes
37 mins., 10
secs.
Preparation of the product took 31 mins.
Dipped bolts into masking material to apply.
Material was runny, like paint.
-
Yes
-
Yes
Dow Corning
Compound #111
Very thick, messy. Smelled awful. Smeared on
w/ foam paint brush. Dried hard, like caulk.
9 mins., 30
secs.
-
Masking
Success
DAP Household
Adhesive Sealant
Wrapped tape around bolts 3 times. Adhesive is
very sticky, and difficult to get off roll and apply.
Application Notes
11 mins., 16
secs.
Application
Time
3M High
Temperature
Aluminum Tape
Product
All bolts picked up excessive zinc.
A lot of the zinc was just frozen,
but many areas galvanized too.
Many areas had zinc frozen
between the threads.
N/A
All bolts lost during testing.
Got 5 bolts back. Almost all
threads were completely bare.
A few small areas picked
up a little zinc.
Some small areas did galvanize.
N/A
4 mins., 57 secs.
N/A
N/A
10 mins., 20 secs.
4 mins., 18 secs.
3 mins., 5 secs.
1 min., 11 secs.
N/A
Used small metal-bristled brush to scrape material
off. Baked-on material was much harder than other
products. Could not remove all of the product.
N/A
N/A
Scraped the material off with a big metal-bristled
brush. The material came off very easily
and the threads had very little residue.
away the material, which came off very easily.
off the material, which came off very easily.
away the product, which came off pretty easily.
Unable to remove tape from threads. This material
would not work as a masking material, as it
cannot be removed w/o damaging the threads.
Tape was nearly
impossible to
remove from
threads
Could not remove masking material.
One bolt was lost during
the galvanizing process.
Received only 1 bolt back (the rest
must have fallen out of the basket
during the galvanizing process). A
few very small areas did galvanize.
away the material, which came off pretty easily.
7 mins., 30 secs.
Threads
were completely bare.
Brushed off black ashy material very
easily with a big metal-bristled brush.
Used a big metal-bristled brush to scrape away the
material, which came off very easily.
Crusty white material came off very
easily w/ a small metal-bristled brush.
Used big metal-bristled brush to scrape away material.
Threads were very clean after scraping material off.
Scraped tape w/ a flathead screwdriver
until it could be peeled off.
Removal Notes
6 mins., 50 secs.
5 mins., 44 secs.
2 mins., 40 secs.
4 mins., 22 secs.
7 mins., 55 secs.
Removal Time
A few tiny areas did galvanize.
Had large bare areas, but
many areas still galvanized.
All bolt threads galvanized to
some extent. Got 4 bolts back.
A few small areas picked up
a little zinc. Got 5 bolts back.
Many areas galvanized.
Some bare areas, but about
half of threads galvanized.
Notes
BOLT THREADS - PHASE 1 TESTING
15
Price
$3.98 / 2.8 oz. tube
$48.00 / liter
$4.97 / 10.1 oz. tube
$120.00 / gal.
$14.19 / 11 oz. tube
$45.00 / qt.
Product
DAP Household Adhesive Sealant
Galva Stop
Maskote Zinc Stop - Off
NAPA RTV Red
Stop Galv
Yes
-
-
-
Yes
-
1 Hour Cure
Time Success
Yes
-
-
-
Yes
-
2 Hour Cure
Time Success
FLAT PLATE
-
Yes
-
-
Yes
-
30 Min. Cure
Time Success
PHASE 2 TESTING - OVERVIEW
Yes
Yes
Yes
-
Yes
Yes
1 Hour Cure
Time Success
BOLT THREADS
Yes
Yes
Yes
Yes
Yes
Yes
2 Hour Cure
Time Success
16
Price
$3.98 / 2.8 oz. tube
$48.00 / l.
$4.97 / 10.1 oz. tube
$120.00 / gal.
$14.19 / 11 oz. tube
$45.00 / qt.
Product
Galva Stop
Maskote Zinc Stop - Off
NAPA RTV Red
Stop Galv
$1.41 / oz
$1.29 / oz
$0.94 / oz
$0.49 / oz
$1.42 / oz
$1.42 / oz
Standardized
Price
Yes
-
-
-
Yes
-
1 Hour Cure
Time Success
Yes
-
-
-
Yes
-
2 Hour Cure
Time Success
FLAT PLATE
PHASE 2 TESTING - OVERVIEW
-
Yes
-
-
Yes
-
30 Min. Cure
Time Success
Yes
Yes
Yes
-
Yes
Yes
1 Hour Cure
Time Success
BOLT THREADS
Yes
Yes
Yes
Yes
Yes
Yes
2 Hour Cure
Time Success
17
-
Maskote
Zinc Stop - Off
-
-
GE 100%
Silicone Caulk
Stop Galv
Yes
Galva Stop
Yes
-
DAP Household
Adhesive
Sealant
NAPA RTV Red
Success
Product
Yes
Yes
Yes
3 of the 5 bolts galvanized
None of the bolts galvanized,
but the material was extremely
sticky and was nearly impossible
to get off the threads.
All five of the bolts
galvanized to some extent.
-
Yes
One bolt had a tiny
spec of zinc on it.
Yes
Success
Notes
30 MINUTE CURE TIME
Yes
3 of the 5 bolts had zinc between
the threads at the top 25% of
the threads. Material was
gummy and hard to remove.
A few small specs of
zinc here and there.
Material was very gummy
and took a long time and
considerable effort to remove.
Yes
Yes
Yes
Yes
1 bolt galvanized a little less
than 10%. Other bolts had
miniscule amount of zinc.
The product scraped off the bolts
very easily.
Yes
Success
Material was gummy and
took a long time to remove.
Notes
2 HOUR CURE TIME
BOLT THREADS - PHASE 2 TESTING
Applied w/ a foam brush. Went on slightly thicker than Galva
Stop and seemed to cover surfaces better than Galva Stop too.
Applied with a foam brush. Material was the
gummiest out of the other materials and took the
longest time to clean from the threads.
Applied with a foam brush. One bolt out of the 5 galvanized
about 10-15%. This material dries extremely fast, which
can make working with it hard. After applying masking
material the outer edges of the threads appeared to be bare.
It still masked the zinc effectively though.
Applied with a foam brush. One bolt out
of the 5 had a little zinc on it.
Applied with a foam brush. Went on very thin. The outermost
part of the threads looked like very little if any material went
on those areas. The product still prevented galvanizing though.
Applied w/ a foam brush. One bolt out of the 5 had a little zinc
on it. The material was very gummy and took longer to remove.
Notes
2 HOUR CURE TIME
Appendix 2.
Pictures of Masking Materials During Phase 1 Testing
18
3M High Temperature Aluminum Tape
19
20
Dow Corning Compound #111
21
Duct Tape
22
Galva Stop
23
24
Kapton Tape
25
Macropoxy 846
26
27
NAPA RTV Red
28
Stop Galv
29
30
VHT Header Paint
31
32
ZYP Boron Nitride Lubricoat
33
Additional Pictures
34

masking materials for preventing hot -dip galvanizing

Transcription

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