NAVAIR 01-1A-509-3
01 March 2005
TM 1-1500-344-23-3
TO 1-1-689-3
g. Relays. Deposits of varnish on the armature,
c. Sealing Compound, MIL-PRF-81733 (Volume IV
pivots, or similar components will cause the relays to
or V, Chapter 2), can be used to seal gaps, seams, and
bind. The whole relay should be carefully masked until
faying surfaces with temperatures up to 250F (121C).
after spraying has been completed. A brush should be
This material is applied by brush.
used to coat the coils and leads after the masking has
been removed. Relays with palladium-tipped contacts
d. C o n f o r m a l Coating. For information on
should be removed before application of varnish.
procedures and equipment used to apply conformal
coatings, refer to NAVAIR 01-1A-23 (Navy) and TO
h. Meters. Since meters are easily damaged by a
00-25-234 (Air Force).
the varnish spray treatment, all meters must be checked
for accuracy before treatment. Some meters may be
CAUTION
affected by heat. In other instances, meter magnets
may be affected by magnetic fields that exist around
A large number of RTV silicone sealants
drying equipment. Refer to the applicable service
contain an acetic acid curing agent. These
directives for instructions on varnish spray treatment of
sealants, in contact with metal, result in rapid
meters. If guidance is not available, do not apply varnish.
corrosion. RTV sealants that contain acetic
acid are not authorized for use on electronic or
5-5. SEALANTS FOR AVIONICS. Sealants are
electrical circuit. They may be identified in
another type of protective film used in avionic
most cases by a vinegar odor while in a liquid
equipment. Sealants are usually liquid or paste, which
or curing state.
solidify after application. They form a flexible seal,
preventing moisture intrusion at mechanical joints,
5-5.2. SEALANT CONTAINING ACETIC ACIDS.
spot-welds, and threaded closures. In addition, sealants
Table 5-1 lists some of the RTV silicone sealants
prevent entry of corrosive environments to faying
considered corrosive. These sealants shall not be
surfaces, fastener areas, exposed landing gears
used in avionic equipment.
switches, and other metal-encased avionic equipment.
They function principally as waterproof barriers. It is
Corrosive Silicone Sealants,
therefore very important that damaged sealants be
Adhesives, and Coatings
repaired as soon as possible.
RTV 102
RTV 192
RTV 999
RTV 92-055
NOTE
RTV 103
RTV 198
RTV 1890
RTV 94-002
RTV 106
RTV 236
RTV 3144
RTV 94-003
For application procedures of Sealing
RTV 108
RTV 730
RTV 20-046
RTV 94-009
Compound, MIL-PRF-81733, refer to Volume
II of this manual.
RTV 109
RTV 731
RTV 20-078
RTV 94-034
RTV 112
RTV 732
RTV 30-079
RTV 96-005
5-5.1. TYPES OF SEALANTS. The following sealants
shall be used on avionic equipment:
RTV 116
RTV 733
RTV 30-121
RTV 96-080
RTV 118
RTV 734
RTV 4-2817
RTV 96-081
a. Sealing Compound, Low Temperature Curing,
MIL-S-83318 (Volume IV or V, Chapter 2), is a quick
RTV 140
RTV 736
RTV 90-092
RTV Q3-6069
cure sealant used for sealing gaps and depressions on
RTV 142
RTV 780
RTV 92-005
RTV Q3-6090
areas during extreme cold activities. Apply with Brush,
RTV 154
RTV 781
RTV 92-007
RTV Q4-2817
Typewriter, A-A-3077 Style T (Volume IV or V,
RTV 156
RTV 784
RTV 92-009
RTV 92-010
RTV 157
RTV 785
RTV 92-018
SCS 101
b. Adhesive-Sealant, Silicone, RTV, Noncorrosive,
MIL-A-46146 (Volume IV or V, Chapter 2), is used for
RTV 158
RTV 786
RTV 92-024
RTV 159
sealing avionic equipment in areas where temperatures
RTV 891
RTV 92-048
are between 250F (121C) to 600F (315C). It is
NOTE
used for encapsulating and sealing of electrical and
RTV 730 is a high temperature (550 to 600 F) corrosive sealant
electronic components. This material has good
that may be required to seal engine compartment electrical
resistance to oxidation, weathering, and water.
connectors. RTV 730 shall be used only when specified by the
cognizant engineering authority.
5-7/(5-8 Blank)
