what is rp grease
Braycote 631 RP. Grease, Rust Preventive, Rocket Propellant Compatible Low Temperature. Castrol Braycote 631RP is a smooth, buttery, off-white NLGI #2 grease based upon a perfluoroether oil. This grease is nonflammable and is in general chemically inert. It is thermally stable either alone or in the presence of oxygen, has exceptionally low volatility, and has little tendency to form deposits.