NAVAIR l7-1-125. This publication takes
precedence over any and all MIMs and service
instruction manuals (SIMs) at both O- and I-level
maintenance activities. This manual spells out
specifically which materials and procedures you are to
use to clean up corrosion and restore the protective
surface. You still follow the maintenance and service
manuals in conjunction with matters not pertaining to
corrosion control. The four primary preservative
compounds recommended for use on SE are listed in
table 4-1.
Apply corrosion-preventive compound to all
exposed SE hardware items (around light brackets,
hand brakes, levers, dissimilar metal joints, and tightly
fitting surfaces and so forth). Preserve areas and
components according to the following general
procedures:
1. After removing corrosion products, clean the
surface and spray the area with water-displacing agent,
MIL-C-81309, type II.
2. Apply an even, thin coating of corrosion-
preventive compound, MIL-C-16173, grade 4, or
MIL-C-85054 to all nonmoving, difficult-to-protect
areas. Use only MIL-C-16173, grade 4, for fasteners.
3. Dip removable screws and fasteners in
corrosion-preventive compound before installation.
4. Remove excess compound from the metal
surface with solvent, P-D-680, and clean cloth,
DDD-R-30.
Sealants For SE
Sealants are brush- or spatula-applied compounds
for SE corrosion prevention. These compounds are
used primarily to repair damaged door and cover
weather seals, fill depressions resulting from
corrosion repair, protect heavy bolts and fasteners, and
seal corrosion-prone crevices and lap seals. Two
sealants recommended for SE are
Silicone Sealant MIL-A-46146, type I, and
Polysulfide Sealant MIL-S-81733 (inhibited) or
MIL-S-8802 (uninhibited).
When properly applied, the sealant forms as a
barrier to the penetration of moisture. Prepare metal
surfaces carefully before the application of a sealant.
Do NOT apply sealant over visible moisture. Ensure
that the sealant forms a continuous film at all seams,
especially where dissimilar metals are in contact.
When applying sealants on SE, you should use the
following steps:
1. Mix the sealant according to the manufacturer’s
direction.
2. Dip bolts or fasteners into the sealant so that the
threads and shanks are completely covered.
Immediately install the bolt in tapped holes.
3. Brush or swab sealant on mating surfaces that
form a crevice when assembling parts. Immediately
assemble these parts.
4. Pour, spoon, or trowel sealant into crevices that
cannot be disassembled for treatment.
Q42. What level of engine preservation requires the
fuel system to remain at least 95 percent full of
fuel for a period not to exceed 60 days?
Q43.
What technical corrosion manual should you use
for support equipment?
Q44.
What are the two sealants recommended for use
on support equipment?
Table 4-1.—SE Preservatives
Preservative compound
Use
Corrosion-Preventive Compound, Water-displacing,
For all exposed metal and hardware not
Ultrathin Film, MIL-C-81309, type II, class 2
exposed to the elements
Corrosion-Preventive Compound, Water- Displacing, Clear, A general exterior surface preservative to
MIL-C-85054, type I (AMLGUARD)
produce an even, thin, nontacky, and clear film
Corrosion-Preventive Compound, Solvent Cutback, Cold
A general external preservative, which
Application, MIL-C-16173, grade 4
produces a semitransparent film
Corrosion-Preventive Compound, Ultrathin Film, Avionics
A general preservative for internal areas of
Grade, MIL-C-81309, type III
electric components
4-19
