Thread: What turns Brass BLACK

Somebodyhere must know the recipe for turning bright clean brass to a dull shade of black, what is the chemical/chemicals called that does this to brass????
What chemical/chemicals will make BRONZE turn into the old worn/weathered look of verdigis???
Somebody must have had to do this to some fittings at some time or other, all answers will be greatfully recieved.

regards radish

Well Radish1us I know exactly how to turn my brass black.
Firstly I take new shiny .300 Win mag brass put about 75 gr of AR 2209 in them & of course a primer & 130 gn slug.
So far they still retain their nice shiny patina.
Unfortunately after I fire them they turn just about black up to about 1/2 way along the case.
So maybe the answer is to put your brass in a pile of powder & light it up.
Perhaps this will tarnish your brass just as quickly. [img]smile.gif[/img]
Cheers Morton

When I was studying metalsmithing years ago, we used to use something called liver of sulphur to blacken brass. It's available through jewelry supply houses like Rio Grande in New Mexico. I think I also found that cold gun blue applied with steel wool will also turn brass black. I haven't done it in awhile but I think I warmed the brass a bit as well.

Bronze and brass can be made to look weathered by soaking the part in a solution of water and ammonia. At first the color will be a dull tarnished-brown appearence. If left long enough (two or three days) the surfice will turn to a green patina. Any kind of house whole ammonia cleaner will work. Brownells sells a solution to turn brass sight inserts black. I do not know what the chemicals are.

seems my hands will do it in a week

amonia will do it.. the artists that use this techinque are begging for a lung problem, but they torch brass and spray amonia on it

jeffe

What Gazz said about cold gun blue works.
I've used it to age brass hardware. You apply it and wait a few minutes.
Then dry, oil and rub with four xxxx steel wool.
A little experimenting back and forth to achieve the look you want.
Jim

Rub with a mixture of salt and vinegar and then expose to ammonia fumes for hours/days. A blue crust will form and under this will be found the green verdigris surface on the brass. I tried some of the brass blackening compound a few years back when I lived in AZ. It turns the brass quite black, a bit splotchy, and is not durable.

Peeing on it will also put a patina on it - not black but a pleasant azure color. A friend had brought me a modern made brass sundial with an "applied" patina on it. I peed on it all summer and the "applied" finish peeled off and now it looks genuinely aged. I handed it to here and then told her how I did it. She got over it though as it did look good.