MIL-PRF-81904C(AS)
3.2.1 Materials. Materials used in the formulation of this coating compound shall
be of such quality to produce coating compounds that meet all of the requirements of this
specification.
3.2.2 Precluded material. Asbestos shall not be used in the formulation of the
coating compound.
3.3 Toxicity. The material covered by this specification shall have no adverse
effect on the health of the personnel when used for its intended purpose and in
accordance with precautions of 3.10 through 3.10.2.
3.4 Condition in container. All components, when packaged and stored in a
closed container(s) and maintained at 60 ±20° F (15 ±1° C) for a minimum period of six
(6) months from the date of delivery to the procuring activity, shall be capable of being
mixed by hand with a paddle to a smooth, homogeneous condition, free of pigmentation
flotation, grit, seeds, skins, or lumps, in accordance with 4.6.2. There shall be no
evidence of hard or objectionable settling which cannot be readily dispersed. The coating
shall spray as specified in 3.5.2. Skinning will be permitted, provided that its removal
does not affect the sprayability of the material.
3.5 Working properties.
3.5.1 Cure time. After the coating is spray applied, it shall be cured to a
minimum hardness of Shore D 55 in no longer than 90 minutes.
3.5.2 Application. The coating compound shall be capable of being sprayed
without sag on a vertical surface to a minimum thickness of 0.08 inch (2 mm). The
coating material shall yield a smooth, uniform film at a dry-film thickness of 0.155
±0.020 inch (4 ±0.5 mm). Other dry film thickness may be used if approved by the
cognizant engineering authority prior to application. No orange peel (wavy appearance)
shall be evident when viewed from six feet away.
3.6 Coating properties.
3.6.1 Thermal efficiency. The thermal efficiency of the coating compound shall
be a minimum of 1 minute plus 1.0 second per 0.001 inch (0.025 mm) of coating to reach
a backface temperature of 500° F (260° C), when tested in accordance with 4.6.4.1. For
retention of qualification testing in accordance with 4.3.1, the thermal efficiency shall
meet the minimum value listed above and the average shall not vary by more than +/- 15
percent from the original qualification average value.
3.6.2 Color and gloss. The color and gloss of the cured coating compound, when
tested in accordance with 4.6.4.2, shall be a visual match to FED-STD-595 color number
36375.
5
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business