(2) On areas and components fabricated
HIGH TEMPERATURE AREAS.
of magnesium or steel. other than corrosion
resistant steel, that are exposed to temperatures.
a. Below 400 F (204 C).
from 400 F to 500 F (204 C 10 260 C). use
silicone finish systems applied directly on the
(1) Surfaces exposed to exhaust gases,
chemical surface-treated metal. omitting the
corrosive fluids, environmental elements, and
wash prime and primer. Unless authorized by the
areas known to be subject to corrosive attacks
government procuring activity. the color will con-
for which ambient temperatures do not exceed
form to the color scheme for the aircraft. Above
350F (177C), finish in accordance with (2)
500 F (260 C) use heat-resistant finishes as
through (3) below.
approved in each instance by the government
(2) Apply two coats of MIL-C-46168 paint.
in appropriate color, over one coat of epoxy pri-
mer, MIL-P-23377 or primer MIL-P-85582.
(3) Areas and components fabricated of
magnesium or steel. other than corrosion resist-
ant steel. that are exposed to temperatures
exceeding 300F (149C). but not above 400F
(204C), either on the ground or in flight (other
than momentarily). finish with MIL-C-46168 in
appropriate color. Use primer. MIL-P-52192. where
ferrous metals are involved.
b. Above 400 F (204 0 C).
(1) Coat aluminum alloy surfaces with
heat resistant point, military specification
Drab and TT-P-28, Color Shade No. 17178, for
These are modified silicone paints
which require heating to 450 F (232 C)
for an hour after application. However,
when applied to turbine engine sur-
faces, the heat generated in normal
operation is considered adequate for
curing. Cured silicone paints will resist
the attack of diester oils.