This material is designed for fillet sealing of properly prepared glass, polycarbonate, acrylic and other aircraft sealing applications. This product is specifically formulated not to craze substrates. The cured sealant exhibits excellent resistance to UV and weather exposure. PR-1425 Class B is a two-part, dichromate cured polysulfide compound. The uncured material is a low sag, thixotropic paste, suitable for application by extrusion gun or spatula. This sealant has excellent adhesion to common aircraft substrates.