Apply CRL KRYLON® Rust Magic Primer to new or rusted iron or steel (after removing loose rust and scale), and it penetrates the rough surface to form a strong, corrosion-resistant bond. Locks out moisture, prevents corrosion, builds the surface, fills in irregularities, provides a surface for colored topcoats. Its protective grip goes right into the pores of the metal surface, which must be free of oil, grease, scale, etc., for best adhesion.