From Rust to Salt Blue...

Heinz · 01-14-2004, 09:02 PM

Viggo, I would offer one correction to your excellent write up. Nitrate is not a necessary component of the blueing compound. I do not know if it is necessary to have nitrogen available to obtain the blue color. I have done a fair ammount of rust blueing with compounds not containing nitrogen (or nitrates) however the stuff we breath is loaded with it and I have never tried the process in a non-nitrogen containing atmosphere.

An excellent reference on the subject is R.H. Angier "Firearm Blueing and Browning" originally published in 1936. Angier says the rust originally formed is ferrous hydroxide which gradually converts to brown ferric oxide. This is converted, often by boiling, to more or less black "magnetic oxide" or ferro-ferric oxide.

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01-14-2004, 09:02 PM	#11
Heinz User Join Date: Jun 2002 Location: Greenville SC Posts: 1,004 Thanks: 377 Thanked 411 Times in 180 Posts	Viggo, I would offer one correction to your excellent write up. Nitrate is not a necessary component of the blueing compound. I do not know if it is necessary to have nitrogen available to obtain the blue color. I have done a fair ammount of rust blueing with compounds not containing nitrogen (or nitrates) however the stuff we breath is loaded with it and I have never tried the process in a non-nitrogen containing atmosphere. An excellent reference on the subject is R.H. Angier "Firearm Blueing and Browning" originally published in 1936. Angier says the rust originally formed is ferrous hydroxide which gradually converts to brown ferric oxide. This is converted, often by boiling, to more or less black "magnetic oxide" or ferro-ferric oxide.