Birchwood Casey's Perma Blue has been the pro's choice for years in touching up nicks and scratches. Easy to use, just clean the metal surface and apply. Birchwood Casey recommends using the Cleaner-Degreaser for cleaning the metal before application. Notes:Perma Blue will give a non-streaky, even blue/black finish to steel (except stainless). All parts to be blued must be free of any rust and oil. Apply without heat with a swab (Q-Tip). Two applications are normally needed.