Technical data

a metal spatula. Keep empty containers and those containing
mixed and unmixed coating tightly closed when not in use.
6.12.18.4 Application.
The dry film thickness of this coating shall be
between 0.8 and 1.2 mils, see Table 5-2. Runs and
sags shall be mopped immediately to prevent
thick spots. Thicknesses over 1.2 mils result in
cracking, flaking and peeling of coating while
those less than 0.8 mils do not provide adequate
protection. Measure the wet film thickness with a
wet film gauge and control the wet film per the
manufacturer’s requirements.
After the tank surface is thoroughly dry and immediately
prior to application of the coating, gently clean the area to be
coated with lint-free cleaning cloth wet with MIL-C-38736/
A-A-59281 cleaner and wipe dry. Do not allow the cleaner to
air dry. Do not abrade the chemical conversion coating film.
Clean small areas starting from the top and farthest from the
access door and work down and out using clean lint-free
cloths/pads. The exception is, for large repair areas where
there must be alternately cleaning, sealing, and coating of an
area and then repeating in the next area while working toward
the access door. Use caution not to contaminate a previously
cleaned area, and reclean immediately if it occurs. Spray all
accessible areas when practical; areas that cannot be sprayed
shall be coated by brush application. Access doors and
removable parts shall be spray coated in a spray booth and
cured in an area with circulating fresh air. Personnel entering
the curing area shall follow all precautions stated in the
“warning” When spraying, apply a light double pass to cover
the surface. Take care to prevent runs and puddles; and if they
occur, remove them immediately.
6.12.18.4.1 Prior to starting application of MIL-C-27725/
SAE AMS-C-27725 and at each change of painters, spray or
brush a small strip of aluminum prepared in the same manner
as described above. Properly adjust the flow of material from
the spray nozzle to provide the proper coating thickness of
0.8 to 1.2 mils dry film.
6.12.18.4.2 Spray Application. Use a HVLP spray gun.
Use a pressure feed tank with 5 PSIG and an atomizing air
pressure of 35 PSIG. Pressure tanks shall be equipped with an
agitator to provide proper pigment suspension. Immediately
after use, the equipment shall be thoroughly cleaned with
MIL-T-81772, Type II.
6.12.18.4.3 Brush Coating. A fine camel hair or soft
hog bristle brush shall be used when applying this coating by
brush. The material shall be stirred with a metal spatula every
3-5 minutes.
6.12.18.5 Drying Time. Curing MIL-C-27725/SAE
AMS-C-27725 coating will be tack free in 4 hours under
normal conditions (75° F and 50% humidity). Cure may be
accelerated after a minimum of 4 hours cure at 75° F by
adding heat up to 120° F. The state of cure can be tested by
rubbing a test spot with a gauze pad wet with MIL-T-81772,
Type II thinner. If bare metal is exposed after 50 double
strokes of the pad at moderate pressure, the coating is not
completely cured.
6.12.19 Coating Compound, Nonslip (For Walkways),
A-A-59166.
6.12.19.1 Characteristics. A nonslip compound formu-
lated in a hand brushable consistency that is fuel and fluid
resistant. These coatings are available in several colors. This
material is compliant with the NESHAP VOC requirements
of 420 g/L (3.5lbs./gal).
Type I This is a smooth coating without grit
formulated primarily for brush applica-
tion.
Type II This is a rough material formulated pri-
marily for brush application containing
grit as an integral part of the coating.
6.12.19.2 Uses. A non-slip is used on aircraft exterior
walkway surfaces to protect personnel from falling while
walking on aircraft surfaces. May also be used on vehicles,
maintenance ramps, steps, ladders and similar areas.
Type I Used along leading edges of aircraft that
fly less than 250 mph and on other
adjacent surfaces of aircraft where the
roughness of the Type II coating is
undesirable due to aerodynamic con-
siderations.
Type II Material used along trailing edges and
adjacent surfaces in cases where maxi-
mum non-slip qualities are essential
and aerodynamics are not affected.
6.12.19.3 Thinning. If thinning is necessary, use the
solvent recommended by the manufacturer. Adjust the vis-
cosity for spray application by thinning to 21 to 27 seconds in
a No. 2 Zahn Cup (16 to 21 seconds in a No. 4 Ford Cup).
6.12.19.4 Mixing and Application. Walkway coatings
are applied to primed surfaces, prior to application of final
topcoat of aircraft coating systems. The topcoat applied over
walkway coating shall be a single mist coat to reduce
distinctive difference in color while not causing loss of
non-slip features. Only the Type II (rough) coating shall be
used under the topcoat of aircraft coating system. Type II
TO 1-1-8
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