WD-40 Specialist Rust Remover Soak (1 US gallon / 3.785 L), a water-based acid-free immersion bath that dissolves rust and restores tools, cast iron, chrome and metal parts to bare metal without chipping, scraping or scrubbing. No toxic fumes; does not harm paint, gaskets or trim. Light rust 1-3 hours, heavy rust overnight. Reusable until spent.