The Bluing Process - What Actually Happens?

Hot salt bluing is a true electrochemical conversion process that transforms the surface level of steel into a form of controlled rust called Magnetite. In order for this conversion to occur, you need a tank capable of holding water that will rest around 290 degrees F and an alkolai salt mixture containing Sodium Hydroxide, Sodium Nitrate, and Potassium Nitrate. It is a little known fact that the color your firearm will turn is based far less on the content of the salt bath and far moreso on the content of your gun! Steel produces the black "blue" sheen that is most common, but if there is a high content of another metal mixed in, you'll get a slightly different hue - a bit of iron will give off a red sheen, and a bit of nickel will give a slightly purple glow, for example. Therefore, it's actually possible to run a whole batch of guns through the same bath and get a whole range of hues!