Form:

This specification establishes the requirements for two types and three classes of a two component, fast curing at low and ambient temperature, polythioether sealing compound for use in sealing integral fuel tanks and other aircraft structures. Temperature capabilities are identified in 1.2.1.

Classification:

The sealing compound shall be classified as follows:

Types: There are two types of sealants furnished to this document. Additionally, Type I is furnished in 3 grades as shown below.

Type I - Fuel resistant sealant for use form -80ºF to +300ºF (-63ºC to +149ºC) with intermittent use to +400ºF (204ºC).

Grade A - For general use in fuel tanks and aircraft structures

Grade AI - Ambient cure or immediate heat cure at temperatures up to 350ºF (175ºC) immediately after application. Available as class B and Class C.

Grade B - Enhanced craze resistance, for use with acrylic aircraft transparencies.

Type II - Corrosion inhibitive, fuel resistant sealant for use form -80ºF to +300ºF (-62ºC to +149ºC) with intermittent use to +360ºF (+182ºC).

Classes:

Class A - Suitable for brush application

Class B - Suitable for application with extrusion gun or spatula

Class C - Suitable for faying surface sealing applications

Application time: The minimum application time in hours for each class shall be:

Class A - 1/4, 1/2, 2

class B - 1/4, 1/2, 2

Class C - 4