PR-1776 Class C is a low density, high temperature
aircraft integral fuel tank sealant. It has a service
temperature range from -65°F (-54°C) to 250°F
(121°C), with intermittent excursions up to 360°F
(182°C). This material is designed for brush sealing of
fuel tanks and other aircraft fuselage sealing
applications. It offers as much as a twenty percent
weight savings, per unit volume, over traditional
sealants used for these purposes. The cured sealant
maintains excellent elastomeric properties after
prolonged exposure to aircraft fuels, (both jet fuel and
aviation gas) and will resist limited contact to
diphosphate ester based hydraulic fluids.
PR-1776 Class C is a two-part, manganese dioxide
cured Permapol® P-5 modified polysulfide. The
uncured material is a roller grade liquid suitable for
application by brush, extrusion gun or spatula. It
cures at room temperature to form a resilient sealant
having excellent adhesion to common aircraft
substrates.
The following tests are in accordance with AMS 3281
Class C specification test methods
