Rust Remover used in the US Navy Leave it for a few minutes after application and wipe it off to remove stubborn rust. Gel-like formula prevents dripping and is highly effective for removing rust on vertical surfaces. Brush paint type for detailed work. Cannot be used for removing rust other than iron (aluminum, stainless steel, etc.) Use on plating parts may cause discoloration. Please try on an inconspicuous area before using. Cannot be used on painted parts. Use for rust removal before painting.