P/S 890 Class B is an 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 275°F (135°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.
P/S 890 Class B is a two-part, manganese dioxide cured polysulfide compound. The uncured material is a low sag,
thixotropic paste suitable for application by extrusion gun or spatula. It cures at room temperature to form a resilient sealant having excellent adhesion to common aircraft substrates.
Thermal rupture resistance – retains pressure of 10 psi with only negligible deformation, both before and after immersion in JRF (AMS 2629).
Low temperature flexibility @ -65°F (-54°C) – no cracking, checking or loss of adhesion.
Corrosion resistance – no corrosion, adhesion loss, softening,or blistering after 20-day immersion in 2-layer
salt water/JRF (AMS 2629) @ 140°F (60°C).
Resistance to hydrocarbons – 7 days @ 140°F (60°C)
immersed in JRF (AMS 2629). weight loss, % 5.0
Flexibility – no cracks after bending 180 degrees over a 0.125 inch (3.18 mm) mandrel.
Repairability to itself – excellent to both freshly cured as well as fuel aged and abraded fillets.
Resistance to other fluids – excellent resistance to water,alcohols, petroleum-base and synthetic lubricating oils, and petroleum-base hydraulic fluids.