P / S 870 Class B anti-corrosion sealant. It has a service temperature range from -65 ° F (-54 ° C) to 250 ° F (121 ° C). With interval trips up to 275 ° F (135 ° C). This material acts as an effective barrier against common causes of corrosion on aluminum alloys or between different metals. Cured sealant retains its elastomeric properties after limited exposure to both jet fuel and aircraft gas.

P / S 870 Class B is a two part, manganese dioxide cured polysulfide compound. The uncured material is a low sag, thixotropic putty suitable for application with an extrusion gun or spatula. It is used to form a flexible sealant that has excellent adhesion to dense aircraft substrates that cure at room temperature.