Technical data
5.6.7 Soil Barrier Coating. If approved by weapon
system technical order, this coating may be applied to all
newly painted aircraft in the jet engine exhaust, APU exhaust,
and gun/rocket blast exhaust areas to protect the newly
painted surfaces. If left unprotected, the above areas will be
very difficult to clean after exposure to the aforementioned
exhausts. This material and application procedures are called
out in TO 1-1-691. If used, the soil barrier coating shall be
applied after the topcoat cures at least 24 hours and prior to
engine run-up.
5.7 INTERIOR FINISHING PROCEDURES AND OP-
ERATIONS.
5.7.1 Preparation For Coating. Cleaning and anodiz-
ing (new parts) or chemical surface treatment of metals and
metal parts per Chapter 3 is a necessary prerequisite on all
interior surfaces prior to priming and painting operations.
5.7.2 Coating Application. Where wash primer per
MIL-C-8514 or DOD-P-15328 is required for interior sur-
faces, follow with TT-P-1757, Type II, Class C both applied
in the same manner and with the same precautions and
restrictions prescribed for external finishing in this technical
order. Other interior surfaces, where wash primer is not a
specific requirement, shall be finished with MIL-PRF-23377
Type I, Class C1 or C2 epoxy primer applied directly on
treated metal. Interior surfaces painted with TT-P-1757 may
be touched up using TT-P-1757 or MIL-PRF-85582 Type I,
Class C1 or C2. The MIL-PRF-85582 Type I, Class C1 or C2
waterborne epoxy primer shall be used to touch-up areas
where TT-P-1757 alkyd primer is present, as solvents in
MIL-PRF-23377 may cause the TT-P-1757 to soften and
flake off. If appearance is of concern, either epoxy primer
may be topcoated. Primer application shall be in conformance
with this section. For areas specified to be a particular color,
Sherwin Williams DTM Gloss Latex Enamel, or MIL-PRF-
85285 Type I polyurethane, shall be applied over the primer
in the desired color and in the same manner and with the same
precautions and restrictions as are prescribed for exterior
finishing in this technical order. For aircraft subject to
spillage or leakage of diester oil or diester grease, the
MIL-PRF-23377, Type 1, Class C1 or C2/MIL-PRF-85285,
Type 1 system is mandatory on the interior surfaces subject to
this contamination such as the wheel wells and their doors,
speed brakes, engine access doors, and main landing gear
doors, in the color specified in the technical data. The interior
colors prescribed by Specification MIL-C-8779 shall be
applied in the locations called out in that specification, the
aircraft drawings, or the aircraft -23 manual.
5.7.3 Refinishing of Fiber Glass Components. Pro-
ceed as follows.
a. Remove the topcoat per Chapter 2.
b. Thoroughly solvent clean per Chapter 3.
c. On the epoxy-primed surface:
(1) Sand the surface with 280 grit abrasive paper and
solvent clean. Do not sand through the primer.
(2) Reactivate the surface per Chapter 3.
(3) Apply 1 coat of MIL-PRF-23377 Type I, Class C1 or
C2 epoxy primer.
(4) Apply 2 coats of MIL-PRF-85285, Type I polyure-
thane topcoat.
5.8 MAINTENANCE PAINTING.
Closely inspect candidate areas for extent of damage and
maintenance painting required. If inspection reveals major
paint failure or damage, such as chipped or peeled paint from
the center of a skin panel, the involved skin section should be
prepared and maintenance painted from seam to seam. If only
minor damage is found, i.e., paint chipped or missing from
screw/rivet heads and on outer edges of skin panel(s) the
specific area may be prepared and maintenance painted.
Prepare damaged area(s) and paint as follows:
5.8.1 Epoxy or Polyurethane Primer/Polyurethane
Topcoat. Proceed as follows.
a. Thoroughly clean area to be repainted.
b. Feather edges of coating adjacent to peeled section and
scuff sand the other area(s) to be coated per Chapter 3.
Use 180 grit paper or nylon abrasive matting material
A-A-58054, Type I, Grade A or B, very fine or fine for
scuff sanding. Grit size down to 120 may be used as long
as care is taken not to score the metal surfaces.
c. Wipe scuffed or sanded areas with approved solvent per
Paragraph 3.1.4. Repair damaged conversion coatings
per Paragraph 3.1.16 and Paragraph 3.1.17.
5.8.2 Primer and Polyurethane Touch Up.
5.8.2.1 Brush or Spray. Proceed as follows:
a. Apply (brush or spray) one thin coat of epoxy primer
Specification MIL-PRF-23377 Type I, Class C1 or C2,
MIL-PRF-85582 Type I, Class C1 or C2, or Polyure-
thane Primer TT-P-2760 Type I, Class C to area being
touched up. Thoroughly mix the primer materials per
instructions in Chapter 6 before use, but the viscosity
need not be checked.
b. Apply one full wet coat of MIL-PRF-85285, Type I
polyurethane topcoat in the required color. If required,
apply a second coat after allowing 1-4 hours curing
period for the first coat.
5.8.2.2 Touch-up Pen. Proceed as follows:
TO 1-1-8
Change 3 5-13