PR-1826 Class B is a rapid cure, aircraft integral fuel tank sealant. It has a service temperature range from -80°F (-62°C) to 320°F (160°C), with intermittent excursions up to 420°F (216°C). This material is designed for fillet sealing of fuel tanks and other aircraft fuselage sealing applications. The cured sealant maintains excellent elastomeric properties after prolonged exposure to both jet fuel and aviation gas. PR-1826 Class B is a two-part, epoxy cured Permapol® P-3 polythioether compound. The uncured material is a low sag, thixotropic paste, suitable for application by extrusion gun or spatula. Unlike standard polysulfide fuel tank sealants, it can cure at low temperatures and is unaffected by changes in relative humidity. This sealant has excellent adhesion to common aircraft substrates when correctly primed with PR-1826AP Adhesion Promoter. The following tests are in accordance with AMS 3277 Type I Class B specification test methods.