The longest-lasting finish, but slower to darken than the liquid blues. Easy-to-use PERMA BLUE Paste Gun Blue reacts slowly with the metal but builds up a denser finish that will outlast the liquid blues. Excellent for touch-up or complete reblueing. Metal must be clean and free of rust (like the liquid blues) and sealed with Sheathￂﾮ Rust Preventive to enhance and protect the finish. A dark blue color may require three or more applications of PERMA BLUE Paste, but each coat takes only 30 to 60 seconds to work. Apply with swab or "Q-tip." Complete instructions on each tube.