what is ospho
OSPHO is a rust-inhibiting coating not a paint. OSPHO causes iron oxide (rust) to chemically change to iron phosphate an inert, hard substance that turns the metal black.Use on new metals, for new ferrous or aluminum metals. Is effective for exterior and interior work alike.lick to zoom. OSPHO is a rust-inhibiting coating not a paint. OSPHO causes iron oxide (rust) to chemically change to iron phosphate an inert, hard substance that ...