"This specification covers a two-component basic zinc chromate-vinyl butyral wash primer for structural steel surfaces prior to painting. It is intended that this coating be used primarily on clean steel free of rust and scale or on clean galvanized metal cleaned according to SSPC-SP 1@ ""Solvent Cleaning""; but it may be used@ when specified@ on steel with very slight amounts of rust. It is to be applied by brush or spray in accordance with SSPC-PA 1@ ""Shop@ Field@ and Maintenance Painting of Steel."""