RE: Birchwood/Casey perma blue
All these blueing solutions,first came out for touch up work on screws and pins ect. They have and will be used by some to try and blue there guns with it. It does make them look better,but will not protect it like the hot bath blueing process. Which is oxidizing on the metal,(just like rust is a oxidizing process).Its come a long way since they first came out. vangunsmith