Well, I have used Brownell's "Classic Rust Blue" and got dandy results. I just dug the old bottle of it out and I see the label refers to metallic salts being in the solution. I have no idea what that means. Mercury? I did two guns with it and honestly didn't notice any odd odors. Remember, you're only exposed to the fumes for as long as it takes to swab the stuff onto the steel, then it goes away (in my case into a damp box) to slowly rust. In re-reading the printed instructions that came with the stuff, there is no mention whatever of maintaining proper ventilation/not coming in contact with it, etc. The warning on the label mentions avoiding contact with the skin and to not get it in your eyes and avoid prolonged exposure to the vapors.
I have also used Laurel Mountain Forge browning solution for both browning and rust bluing. I don't have any left so I don't have any reference as to its contents. The results were fine, and I don't recall any noxious odors.
Lastly, for the last gun I did I used a home made solution that supposedly duplicates A.O.Niedner's recipe.
2.5 oz. Nitric acid
2.0 oz. Hydrochloric acid
1.0 oz. iron nails
30.0 oz. distilled water
As you can see it's a very weak acidic solution. I mixed it using chemicals we have here in our labs at the school (I honestly don't know the strength of the acids, but it is fairly pure stuff.) Instead of iron nails, I used iron filings, again from the science labs. I read somewhere to be sure of the chemical makeup of the metal you dissolve into the acid- using alloy steels may impart traces of elements detrimental to the process. The iron filings were dissolved first in the acid, then mixed with the water. (Always add acid to water, never the reverse.) I also reduced the quantities of the ingredients so as not to end up with a quart of it, and used brown glass containers.
That was more of an experiment and admittedly a self-challenge. The results were a very pleasant grey-blue almost black.
Quite frankly if anybody tries this at home, and I still see no reason why not, allay your own suspicions by determining the contents of the solution and take the necessary precautions. It still ain't rocket science. And as far as exposing my family to any danger- I'm single and live alone, plus all this stuff is done in my shop where I'm all by my lonesome. I would still do it in the kitchen if that were my only venue.
Not a "resident expert". Just stating what I have done myself. My personal physiological makeup is rather more sensitive than most people's, and I have never experienced any side effects whatsoever. Some of stuff the cleaning lady has stashed under the sink brings tears to my eyes and makes me gag, quite unlike my experiences doing rust bluing.
Last edited by gnoahhh; 01/07/12.
