Quote Originally Posted by yebo View Post
gun blue is the coating on guns. Meron nabibili sa mga gun stores, sabihin mo lang gun blue. Mura lang yun, nasa P200 per tube or bottle. It is actually a kind of salt that when applied on metal produces a very hard oxide coating that will serve as protection for the metal.


purely cosmetic only. it doesn't provide any kind of protection

real "bluing" involves dipping in hot caustic solution