Rust-Oleum Rust Reformer instantly bonds with rust and transforms it to a non-rusting, flat black paintable surface and prevents future rust. It saves you the effort of sanding rust all the way down to the bare metal. Instantly converts rust to a protected, paintable surface. Instantly converts rust to a protected, paintable surface. Oil-based formula. Flat finish, and dries in 20 minutes. 12 oz. can cover up to 10 sq. ft. If no topcoat is desired, a second application is recommended. Do not apply to surfaces that exceed 200°F. Clean up with mineral spirits.