Form This specification covers three types and three classes of fuel-resistant polysulfide (T) sealing compound with low specific gravity@ supplied as a two-component system which cures at room temperature. Application This sealing compound has been used typically in sealing aircraft integral fuel tanks@ fuel tank fillets and faying surfaces@ pressure barriers and moldline surfaces@ but usage is not limited to such applications. The sealing compound is resistant to jet fuels and is capable of withstanding long-term exposure from -65 to +250 ??(-54 to +121 ?? and short-term exposure (six hours) to 360 ??(182 ??. Classification Type 1 - Sealing compound with a specific gravity of 1.20 to 1.35. Type 2 - Sealing compound with a specific gravity of 1.06 to 1.19. Type 3 - Sealing Compound with a specific gravity of 1.05 or less. Sealing compounds covered by this specification are classified by method of application and application times as follows: Class A Suitable for application by brushing@ injecting@ or spraying. Available with the following application times in hours: A-1/2 A-2 Class B Suitable for application by extrusion gun or spatula. Available with the following application times in hours: B-1/2 B-2 Class C Suitable for faying surface or shim sealing@ brush coating@ or wet installation. Available with the following application times in hours: Notation: ( ) Assembly time in hours. C-2(2) C-8(24) C-12(48) C-48(168) C-96(336) Safety - Hazardous Materials Shall be in accordance with AS5502 (1.1).