TO 35-1-3 - Robins Air Force Base

TO 35-1-3
3.22.1 SE Undercoating Considerations. The undercoat
may be applied to a primed surface. Topcoating in this area
prior to undercoating is not required. Ensure the undercarriage
of the equipment is clean prior to application of the undercoating.
Do not apply over corrosion.
NOTE
For maximum corrosion protection, undercoating
should be applied by the original equipment manufacturer
during production.
3.22.1.1 The undercoat is not fluid resistant and fuels/fluids/
solvents will readily cause deterioration of the coating. Undercoat
should not be used in an area subjected to fluid spills.
3.22.1.2 The undercoat should never be applied over a component
(such as a transmission) where the coating would result
in the undesired retention of heat.
3.22.1.3 Undercoating is not resistant to temperatures in
excess of 325 °F and should not be used in such areas.
3.23 STORAGE COMPARTMENTS.
Storage compartments for ducts or hoses, which use a pad, or
matting for abrasion resistance are highly susceptible to corrosion
because of the water absorbing characteristics of those
materials. Field activities should remove the pads/matting and
replace the mat with an abrasion resistant floor covering by
using one of the following techniques after removal of all
corrosion and the surface is completely prepared for the
selected coating.
a. Apply MIL-PRF-81733 sealant 1/8 inch thick over a
clean primed and painted surface.
b. Apply Scotch Brand Abrasion-Resistant Polyurethane
Film (8561) over a clean primed and painted surface.
The film is available in four inch wide rolls and can be
easily trimmed to fit any contour or shape. The surface
must be clean to permit the adhesive backing to bond
properly.
c. Apply 85/15% zinc/aluminum metallization 4-6 mils
thick on bare, abrasive blasted steel surfaces.
d. Apply a sprayable polyurethane truck bed liner type
coatings, Morton Paint Company, PN 1440-2, or equivalent
on high wear areas and storage compartment interiors.
Colors shall be black or consistent with the existing
color utilized on the equipment. The coating shall be
applied over the existing primer and polyurethane topcoat
paint system.
3.24 SPLIT WHEEL ASSEMBLIES.
3.24.1 Split Wheel Coating Requirements. To prevent
corrosion on the mounting flanges of the split wheels accomplish
the following:
3.24.1.1 Remove all corrosion and clean the flanges.
3.24.1.2 For carbon steel wheels mechanically clean the split
wheel assemblies and apply 0.002-inch thickness of zinc-rich
primer, MIL-PRF-26915, to each of the surfaces. Allow paint
to completely dry per the manufacturers application data.
3.24.1.3 MIL-DTL-53022, Type II, is an acceptable alternate
for zinc-rich paint on split wheel assemblies only if the necessary
surface preparation equipment is not available.
3.24.1.4 If primer is used, apply a thin film of uncatalyzed,
low adhesion sealant PR-1773 to the mating surfaces of the
split wheels after the primer has cured to prevent fluid intrusion
and assist in future wheel disassembly.
3.24.1.5 Reassemble per applicable technical order and
apply a bead of sealant RTV MIL-A-46146 around the inflation
valve stem to prevent water entry. Tires will be treated
with a commercial tire dressing, and all valve stem caps will
be plastic.
3.25 MUFFLERS.
To reduce corrosion problems on muffler components a thermal
sprayed aluminum coating may be used. The effectiveness
of the coating is dependent upon the particular component and
the environment (temperature, time at temperature, and time to
reach temperature). The effectiveness will also be dependent
upon the condition of the component prior to thermal spraying,
the coating will be more effective on a new component
than on a reconditioned component that had already rusted.
Change 8 3-17