WD-40 Specialist® Rust Remover Soak quickly dissolves rust and restores tools, equipment, and surfaces to bare metal without chipping, scraping or scrubbing. Great for removing rust from tools, metal, cast iron, chrome parts, and more without harming paint, gaskets, trim, or other surrounding parts. This rust-removal formula has no toxic fumes, does not use acids or caustic chemicals, is non-irritating to skin,  and is safe to use on most metals. To remove light rust, leave parts in the solution for 1-3 hours. To remove heavy rust, leave parts in the rust removal solution overnight. Do not use on parts that have bluing, browning or protective oxide paints, as those protective coatings would be removed.