Fire Bluing
 

Would like to know the "formula" for fire or nitre bluing parts, such as seen on the front site, grip screws, toggle pins and even magazine pins. Randall Gibson on page 51 of his Krieghoff Parabellum, states that heating the part in a 550 degree oven for fifteen minutes gives the part a deep blue color. But is this the fire blue color? Would appreciate opinions from our expert refinishers.

From what I've read, Lugers use Slow Rust Blueing and Salt Bluing on later models. Charcol Bluing is something that is on Colts. Not German Lugers.

Togglelock,
You are correct for the large components of the Luger, but notice that Dr. Fisher is referring to the small parts that are indeed "fire" or nitre blued on the early rust blued Lugers.

Thanks, Ron, for the clarification. These fire blued parts are very striking to the eye and, unfortunately, very fragile and not long lasting if not care for. Thor (Ted), would you be exposing any "trade secrets" by revealing this information? You seem to have this technique mastered as well if not better than the original DWM guys.

I dont discuss my methods. Sorry.

Appreciate your reply, Ted. An artist like you should keep your methods sacred. The "Modern Gunsmith" coloring chart depicted on our Members Gallery says the "bright blue" is obtained @600 degrees, presumably for 15 minutes, although this is not stated. Will try this and see what happens.

Thanks Herb, I appreciate it!

Herbert check your private messages.

Dr.Herb, Fire bluing can either be done in the oven or with a torch. The real secret is the polishing and that the part is ultra clean, before heating. TH

Herbert,
I would be VERY CAREFUL abouy Torch Blueing any Tempered Parts, ie; Springs, Extractors, Ejectors, or Magazine Latches.
The temper of these parts are critical and if over heated they may not be servicable and fail prematurely.
I would advise much practice before attempting Straw Tempering with a Torch.
Even after more than 40 years of experience I still Practice on similar sized steel scrap before the tempering of an actual part.
Viggo