The fast rust bluing/hot water bluing did not degrade the markings on my pistol. And you do not need a cabinet to do it, just a heat gun. Heat the metal, swab on the fluid and it flash rusts. You boil it, card it, and repeat until you get the finish you want. Then just neutralize the parts in a solution of water and baking soda. Take them out, dry them and oil them. Wait a day or two and then you reassemble. It is still a rust blue, just an express version.