Use RustFree™ to quickly remove rust, corrosion and stains from virtually any surface, including: steel, cast iron, stainless, fiberglass, chrome, tile, porcelain, vinyl, cloth and more. Use Boeshield T-9® after cleaning with RustFree™ to protect bare metal surfaces. Directions. For light rust on steel or cast iron, spray RustFree™ on a rag and wipe surface. Do not spray directly on surface, as it may cause spotting. For heavy rust, spray directly on rusted surface and scrub with Scotch-Brite™ pad. Wipe off and repeat if necessary. RustFree™ works best above 70° F. CAUTION! RustFree™ is acidic and should be used with care. Test on hidden area before use. Can cause spotting on cast iron and steel. Rinse off painted surfaces thoroughly and neutralize with soap and water. Do not use on guns or black oxide tools. Can dull paint and plastics. Not for spot cleaning of table tops. Do not use on polished cast iron surfaces.