3.1 First article sample. Unless otherwise specified (see 6.2), a first article
sample shall meet all the requirements of this specification.
3.2.1 Composition. The material shall be a pre-mix consisting of a glass
reinforcement impregnated with an epoxy resin system (see 220.127.116.11).
18.104.22.168 Reinforcement. The reinforcement shall meet the requirements of
MIL-R-60346, Type I, K-37 Glass, Class 1, except that it shall be chopped.
Reinforcement shall consist of 50 5% by weight of 0.250 0.062 inch long fibers
and 50 5% by weight of 0.125 0.062 inch long fibers (see 4.5.4).
22.214.171.124 Resin system. The resin system shall consist of epoxy resin
conforming to MIL-R-9300, Type I, Grade O, Form A, modified with a suitable
elastomer (see 126.96.36.199).
3.2.2 Storage life. The material as furnished by the manufacturer shall be
capable of meeting the requirements specified herein after storage at a maximum
temperature of + 4.4 Celsius (C) for not less than 90 days (see 188.8.131.52).
3.3 Performance characteristics.
3.3.1 Physical and chemical properties. The physical and chemical properties
of the material shall be as specified in Table I.
Physical and chemical properties.
Resin content, % by weight
Volatile content, % by weight
Gel time, minutes
3.3.2 Mechanical properties. The mechanical properties of the material shall
be as specified in Table II.