01 March 2005
Change 1
NAVAIR 01-1A-509-3
15 July 2008
TM 1-1500-344-23-3
TO 1-1-689-3
Chapter 2), is a two-part synthetic rubber compound. It
a. Apply potting compounds only to thoroughly clean
consists of a base and an accelerator (curing agent)
surfaces.
packaged together. It is used for sealing low voltage
electrical connectors, wiring, and other electrical
b. Follow instructions carefully when mixing the
apparatus, where temperature does not exceed 200F
base compound and accelerator. Substitution, partial
(93C). Verify maximum temperatures in high
temperature locations such as engine bays, keel areas,
accelerator may produce a sealant with inferior
or areas adjacent to bleed air ducts prior to use.
properties.
c. Do not mix base compounds and accelerator
is used for sealing electrical connectors electronic
components of different batch numbers because
components where a more flowable, one-part material
substandard electrical properties may result.
is required.
d. Potting compounds may contain small quantities
c. Sealing Compound, MIL-PRF-81733 (Volume IV
of flammable solvents, and/or release by-products on
or V, Chapter 2), is used to prevent entry of corrosive
curing. Adequate ventilation and fire precautions are
environments.
required during mixing, curing, and/or storage of potting
compounds.
d. Molding and Potting Compound, MIL-M-24041
e. Potting compounds that have exceeded normal
polyether polyurethane system consisting of a
shelf life are not to be used unless retested and
prepolymer and a curing agent before mixing. These
certified.
compounds are flexible cold-flow and cold-resistant
materials with excellent electrical properties and are
f. Avoid the use of masking tape and fiberboard
intended for use in a seawater environment. This
molds. If potting molds are not furnished with connector
compound will adhere to metal, rubber, or polyvinyl-
or are not available, a plastic sleeve should be
chloride, and may be used for the sealing and
constructed. This will aid in forming the potting
reinforcement of electrical connectors, wiring and other
compound around the connector shell.
electrical apparatus. This compound is used to seal
connectors located in areas where the temperature
g. Allow potting compounds to cure until firm prior
range is -80F to +300F.
to installing connectors or components in equipment.
h. Frozen, premixed, potting compounds should
NOTE
be used as soon as possible after the removal from the
Electrical connectors should be examined for
deep freeze or a significant (approximately 50 percent)
reduction in work life can be experienced.
(reversion). If soft, spongy, doughy, viscous,
or flowing conditions exist, the connector shall
i. Remove reverted potting compounds as soon
be replaced in accordance with NAVAIR
as possible.
01-1A-505 (Navy), TO 00-25-234 (Air Force),
or TM 55-1500-323-24 (Army).
5-4.3. FUNGUS-PROOF COATINGS. Fungus-proof
coatings should not be applied indiscriminately to all
5-4.2.2. Reverted Potting Compounds. Depending on
electronic components. Treat only those components
the environment, potting compounds, such as Pro-
that have been treated or are specified in the applicable
Seal 777 (green) and EC-2273 (black), are known to
service directives. Fungus-proof coatings can, in some
revert to a liquid after a year or two. Compounds that
instances, be detrimental to the function/maintenance
revert exhibit a sticky, oozing consistency that flows
of equipment. For example, it deteriorates wire insulation
out of the connector. In some cases, the reverted
and its removal is labor intensive. The IMA shall retreat
potting compounds flow around through the pins and
the entire surface only when touch-up procedures will
not provide protection to the item. Considering the
difficulties of applying a fungusproof coating, it is
important to recognize that if the coating is not
5-4.2.3. Precautions. When using potting compounds
maintained properly, many hours of additional repair
time will be required.
the following precautions shall be followed:
5-4