Birchwood Casey Perma Blue Gun Finishing Kit PasteThis kit contains everything you need to touch up or even completely reblue most guns. Perma Blue provides great blueing to metal that has already been thoroughly cleaned and is free of rust. Perma Blue Paste Gun Blue is slower to darken than Liquid Gun Blue, but will build up a denser finish. The kit includes what you need to remove all rust and old blueing before you reblue. Removes old finishes without damaging the base metal.