Blue Wonder Gun Blue 1 oz Touch-up Kit Blue Wonder™ Gun Blue will only bond to itself and bare ferrous metals, and will not bond to or affect the existing Factory Bluing on your gun. In addition, Blue Wonder™ Gun Blue is the ONLY gun blue available, where you can add coats one by one until you reach the exact darkness of the existing Factory Bluing on your gun! AND - if you don’t get it right the first time, you can simply continue the process, until the exact darkness you desire is reached - without having to strip the bluing and start over each time from the beginning. Deeply penetrates and bonds with the metal to "Look and Wear" like Hot Blue. Any shade of blue can be easily obtained, from very light to deep, dark blue. No need for special, expensive equipment. No special skills required to use. No need to send your gun away to be blued. An entire gun can be re-blued, virtually in “minutes”. No residual “Rotten Egg” odor.