TO 1-1-700 - Robins Air Force Base

TO 1-1-700
MIL-PRF-87937, CLEANING COMPOUND, AIRCRAFT 52
MIL-DTL-81706 (ALODINE), COATING, CHEMICAL
CONVERSION 23
MIL-PRF-85570, CLEANING COMPOUND, AIRCRAFT 51
a. Clean surfaces with a MIL-PRF-87937, Type IV or a
MIL-PRF-85570, Type II alkaline, water based cleaner
per procedures in Table 7-1 to remove protective chipping
treatment, dirt, oil, grease, welding flux, and loose
scale followed by solvent wiping per procedures in
Chapter 3 of TO 1-1-8.
b. The properly cleaned surface shall be treated with an
SAE AMS-M-3171 (MIL-M-3171), Type VI brush on
chromate treatment per procedures in Section II of
Chapter 3 in TO 1-1-691.
MIL-PRF-23377, TYPE I & II, PRIMER, EPOXY CHEMI-
CAL AND SOLVENT RESISTANT 38
c. Apply two coats of MIL-PRF-23377, Type I, Class C
epoxy primer to all properly prepared and treated surfaces,
exposed and unexposed to a total DFT of 1.2 and
1.8 mils (0.0012 to 0.0018 inch). Application shall be
per procedures in Chapters 4, 5, and 6 of TO 1-1-8.
MIL-PRF-85285, COATING, POLYURETHANE, HIGH
SOLIDS 50
d. Apply two coats of MIL-PRF-85285 polyurethane topcoat
over the primed surfaces to a total topcoat DFT of
1.8 to 3.2 mils (0.0018 to 0.0032 inch) over the primer
per procedures in Chapters 4, 5, and 6 of TO 1-1-8. The
color and gloss shall match the existing coating system
as specified in equipment system specific technical data
or as otherwise directed by the equipment SPM.
7.7.4 Zinc and Cadmium Plated Surfaces. When complete
refinishing is required due to extensive corrosion or loss
of film adhesion, disassemble the equipment and/or structure
as far as practical; and remove the defective paint system per
procedures in Chapter 2 of TO 1-1-8.
Cadmium and zinc platings are extremely toxic to
eyes, skin and respiratory tract. Eye, skin and respiratory
protection is required. Good general ventilation
is normally adequate. Cadmium is also toxic if ingested.
Wash hands thoroughly after handling or
working with cadmium plating before eating, drinking,
or smoking.
NOTE
The presence of a white powdery oxide formation on
cadmium plated surfaces, in particular fasteners, will
not in itself constitute reason for disassembly or overhaul
unless these deposits interfere with proper operation
of equipment. It will be sufficient to brush off
accessible deposits of oxide with a stiff bristle brush,
nonabrasive, and treat affected surface with MIL-
DTL-81706/MIL-DTL-5541, Class 1A solution while
treating the surrounding aluminum alloy structure.
7.7.4.1 For DEPOT LEVEL maintenance only, strip old plating
from equipment or part to the base metal per procedures in
TO 42C2-1-7. For FIELD LEVEL maintenance and when it
impractical to strip the plating due to size, shape, or connection
to other parts, lightly sand areas where corrosion is noted
to remove corrosion products of the plating as well as the base
metal per procedures in Chapter 5 of TO 1-1-691.
7.7.4.2 If the surface is exposed to direct view in its normal
operating condition, the following procedures shall be used:
a. For DEPOT LEVEL maintenance only, replate surfaces
with zinc per ASTM B-633 (QQ-Z-325) or cadmium
per SAE AMS-QQ-P-416 (QQ-P-416) using procedures
in TO 42C2-1-7. Both zinc and cadmium plating shall
have at least a Class 2 coating with a minimum thickness
of 0.2 mils (0.0002 inch) and preferably a Class 1
coating with a minimum thickness of 0.5 mils (0.0005
inch).
b. Zinc plated surfaces shall receive either a Type II supplementary
chromate treatment or a Type III supplementary
phosphate treatment per ASTM B-633 (QQ-Z-325)
using procedures in TO 42C2-1-7. Bleached or clear
chromate treatment is not permissible.
Change 1 7-29