Need some help blackening brass shim stock for new shutter and iris blades

[Pierre 2]

Thanks again to Luka for providing me with some of that blue wonder + your demonstration was very convincing !!! Will have at least one shutter re-assembled tonight :-)

Pierre, i have what you need. its silica acid and it will turn your brass in to mat black. i use this oxidant to finish some watch parts. like tis one; this is braonze after treatment (watch case not yellow, more natural parts)

i am in Montreal as well and you can just bring parts and we can make them black shoot me PM

[jp]

Just look at the store for a warning not to mix with bleach. That's usually meaning it's an ammonia product. Yes, we still have it in stores in the US a cleaning products. Never tried it to blacken anything.

[Pierre 2]

Thanks for the mention. Alone, I believe that ammonia will actually brighten brass. To get a darkening solution, someone on the web is advising to saturate a portion of ammonia with whatever quantity of copper carbonate it will dissolve. May still try it since I already found some cupric powder treatment for plants which MAY be copper carbonate (will do this outside with glasses and gloves) and would anyway like to have ammonia on hand for brightening purposes. Will eventually post the result of that test.

[Ralph Weimer]

Luka, do you mean Silicic Acid?

Ralph

[Pete Watkins]

In the 60's & 70's we used a hot solution of ammonia and soft soap to clean up brass and kill verdigrease (green crap, it's to brass what rust is to ferrous metals). With a brushing with pumice powder it can strip old damaged lacquer as well. Without the scrubbing it will only clean the dirt off, not brighten brass.
Don't ask me for quantities as it was always a hit and miss process. A warning, it stinks and spouses will complain, a lot!
Pete.