TotalBoat Lust Rapid Recoat Marine Spar Varnish can be applied to clean steel after proper surface preparation. Remove all grease, oil, and other contaminants, then sand the surface to ensure proper adhesion. The surface must be dry before applying the varnish. Although spar varnish is designed for wood, it is suitable for exterior use on various surfaces, including metal.

For ferrous steel, abrading the surface immediately before application is strongly recommended. Alternatively, use TotalBoat Rust Primer Metal Treatment as directed to help prevent rust and oxidation. The rust primer may impart a slightly darker color.