adding a patina to new brass flanges.

[Carsten Wolff]

Dunking it in diluted vinegar and then letting it dry only cleans it, right? Dropping it in old fixer may also work though.

[sun of sand]

i thought it was hot sepia toner sodium sulfide that will age-blacken brass

maybe any will do equally

[Robert Opheim]

I understand that lemon juice will get brass to tarnish. I know of a Brass door that had a patina on it at a church. The parishioners thought it looked dirty so they used brass polish and cleaned it. The patina was the intended look for the door - lemon juice or another acidic acid was used to restore the patina. This should work as long and there isn't a lacquer on top of the brass.

[goamules]

No, acid removes patina. Both lemon juice and vinegar will quickly turn an old brown piece of brass into shiny yellow. However, it is not even recommended for cleaning, because it etches the metal, removing microscopic amounts, it leaches the copper or "plates" copper onto the surface, turning the brass an unnatural copper color. And it has been reported to make the brass brittle. It should not be used in conservation or attempts to make "patina".

[Scott Davis]

On a related note, I have some brass I want to blacken (replacement waterhouse stops, among other things). What's the recommended chemical for doing this, and where should I look for it?