PS Magazine - TB 43-PS-668
PS, The Preventative Maintenance Monthly
ISSUE 668
JULY 2008
Paint Removal
There are times when you need to remove WD
CARC from a surface that can’t be scratched
or scored—like hydraulic cylinders, cannon
mounts and aircraft surfaces. You can’t grind or
sandblast without damaging the equipment.
In those cases, use epoxy and polyurethane
paint stripper to remove the WD CARC. Make
sure you wear protective gear, including rubber
gloves and eye goggles.
31
PS 668
JULY 08
•
Cleaning.
Wash the surface thoroughly
with a solution of liquid detergent, NSN 7930-
00-282-9699, and water. You must remove all
loose sanding debris, grease, oil (including
Fngerprints), and fuel residue to ensure the
WD primer and WD CARC will properly stick to
the surface. Rinse completely with clean water
and let the area dry. Crevices and seams will
take longer to dry, so make sure all moisture
is gone before continuing. Be very careful to
keep the surface free of dirt, dust, Fngerprints
and other contaminants after cleaning.
•
Pretreatment.
If the old paint is sound
and you don’t have to sand to bare metal, you
won’t need the pretreatment and WD primer
steps. Otherwise, immediately coat all bare
metal surfaces with a coat of wash primer.
The wash primer protects the surface and will
help the WD primer bond to it. A sponge gives
better control for this application.
Paint Failures
There are a number of
reasons why WD CARC may
fail soon after application:
Step-by-Step Touchup
After the pretreatment coating is
dry—at least 30 minutes, but no more
than 24 hours—brush on a coat of WD
primer. The WD primer will dry hard in
about Fve to six hours. High humidity
and low temperatures will slow the
drying process.
Once the WD primer is dry, it’s time to apply the WD CARC topcoat. WD CARC
is available in bulk kits of 3 pints, 3 quarts, 3 gallons or 15 gallons. You can also
use self-contained touch-up kits for stenciling or spot painting small areas. These
kits come in an aerosol spray, a sponge roller applicator and brush-top applicator.
Choose the one that best suits your needs.
Thoroughly mix the WD CARC topcoat following
the instructions that come with the paint. Be especially
careful not to thin the paint with too much water.
Use a paint brush or roller to apply the WD CARC.
Apply the paint lightly at the outer edges and heavier
as you move to the middle. That rebuilds the paint
layers to the original thickness.
Q±Y
N²N³
8010´00´
142-9273
181-7568
926-1488
926-1489
1 pt
1 gal
5 gal
55 gal
Be careful where you use the stripper, though.
It can damage non-metal surfaces such as plastic
and rubber.
Topcoat cure time will depend on temperature and humidity, but at an optimum
temperature of 70°±, Type I WD CARC will dry to the touch in approximately 50
minutes, dry hard in four hours, dry through in Fve hours, and completely cure
within seven days. Type II WD CARC will dry to the touch in approximately 60
minutes, dry hard in six hours, dry through in eight hours, and completely cure
within seven days.
•
The surface was
improperly prepared. There
was loose or blistered paint,
sanding dust, grease or oil,
diesel fuel, or Fngerprints
on the surface. Or it could
be that a non-CARC paint
was used previously and not
removed.
•
No pretreatment or primer
was used. The topcoat was
applied directly to bare
metal.
•
The primer did not have
time to dry properly before
the topcoat was applied.
•
The surface was too hot or
cold. The paint didn’t have a
chance to cure properly.
As with most paint
failures, the only sure cure
is to strip it down to bare
metal and start over. It takes
a lot longer to do it over, so
your best bet is to do it right
the Frst time.
now that you’re
ready to spot paint
your vehicle, follow
these steps.
..
improved paint
strippers for
removing WD
CARC are being
developed.
until then,
use the stripper
that comes with
these nsns…
WAsh±wiTh±deTerGenT±
And±wATer
Apply pretreatment
to bare metal only
Brush on primer…
…Then±Add±ToPcoAT
RebuiLd±PrinT±LAyers±for±smooTh±Fnish
RePAir±ToPcoAT
RePAir±Primer
BAre±meTAL
668.30-31.indd
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6/6/08
2:02:04 PM
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