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 air- craft fuselage sealing applications. The cured sealant maintains excellent elastomeric properties after pro- longed 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 tempera- ture to form a resilient sealant having excellent adhe- sion to common aircraft substrates.
The following tests are in accordance with AMS-S- 8802 Class B specification test methods.
Performance Properties (Typical)
Cured 14 days @ 77°F (25°C), 50% RH
Cured specific gravity 1.55
Nonvolatile content, % 95
Ultimate cure hardness,
Durometer A 49
Peel strength, pli (N/25 mm), 100% cohesion JRF(AMS 2629) immersion, 7 days @ 140°F (60°C)
Color Part A
Part B Mixed
Mixing ratio By weight
(Brookfield #7 @ 2 rpm), Poise (Pa-s)
Black White Gray
Part A: Part B 10:100 or 1 to ten