Types 1 and II materials are suitable for use as rust removers for ferrous metal parts and as metal conditioners for ferrous and nonferrous metals prior to application of paints and/or corrosion preventives. Very heavy rust incrustations should be mechanically removed and heavy Greens should be removed by adequate grease solvents or grease removal methods. Type I material will remove more rust and grease than type II. Type I material should always be rinsed off with water after application. Type II material does not have to be rinsed off with water but may be wiped off with clean rags prior to painting.