The Birchwood Casey Perma Blue Liquid is the proven way for touching up or complete reblueing firearms.
This fast-acting liquid gives a non-streaky and uniform blue-black finish, offering the best way to touch up scratches and worn spots or even completely reblue your gun.
Perma blue paste gun blue is slower to darken than liquid gun blue but will build up a denser finish.
Please note that perma blue liquid gun blue will not blue stainless steel, aluminum or non-ferrous metals.