BIRCHWOOD CASEY - Super Blue® Liquid Gun Blue (R2)

Super Blue® Liquid Gun Blue is a double-strength blueing solution designed for blueing highly polished steel parts and hardened steels containing nickel and chrome alloys. 
The blackest blue among others. 
Use caution to confine the solution to the area to be reblued, as it will have an effect on the existing blue. 
Apply with swab or sponge to a clean, rust-free surface. 
Protect and enhance the new finish with BIRCHWOOD CASEY Barricade Rust Protection or oil. 
All parts to be blued must be thoroughly cleaned with a metal cleaner such as BIRCHWOOD CASEY Cleaner-Degreaser and any rust must be removed before applying the blue. 

(Notes: It will not blue stainless steel, aluminum or non-ferrous metals)