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 Sheath® 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. Complete instructions on each tube. Apply with swab or “Q-tip.”.