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

[Pierre 2]

Hi all,

Already tried gun blue (way to harsh : getting a nasty crust).

Found some "cupric treatment" powder in a plant store (hope it is copper carbonate). Can no longer find ammonia in stores (and lost the one quart bottle that I had) :-(

Also have copper sulfate on hand, muriatic acid, acetic acid (of course), nitric acid (to passivate SS tig welds), sulfuric acid (battery acid) and some other house products like TSP etc...

Is it possible to still buy a bottle of ammonia in a hardware store in the US ? (border is quite close and I go from time to time to pick up my auction purchases).

Any other suggestion (my green dishwashing soap did not work either, nor did the dishwasher soap).

Thanks in advance !

[LabRat]

The stock finish on AK-47's is old motor oil spread on the surface, and heated with a torch flame...

Liver of sulfur solution is used to blacken in jewelry making...

Teflon paint is used for sliding parts, (and tough!!!)

Steve K

edit; oops, my screen was on zoom, and missed the shutter and iris blades part... (Too much heat to distort parts...) Sorry!!!

The liver of sulfur solution would work... Try a 99 cent store in the cleaning supply section for ammonia...

[cikaziva]

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)

http://i637.photobucket.com/albums/uu96/nejad_ljemani/DSC01745_zpsvy0b43vh.jpg (http://s637.photobucket.com/user/nejad_ljemani/media/DSC01745_zpsvy0b43vh.jpg.html)

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

[LabRat]

I tried to find "silica acid", but I find no mention of it anywhere... (Is this a typo???)

If you can describe or link the process, please, as it would be useful...

Thanks in advance,

Steve K

[Nodda Duma]

Ammonia is available at places like Walgreens or Lowe's. Looking in the cleaning section. Just bought some myself.

[redshift]

There is a chemical supply house on the Bay that sells small quantities of "reagents". Lab quality stuff. I bought an ounce of 28% ammonia recently.

[pdh]

won't selenium toner blacken brass?

[Pierre 2]

Thanks to all !

Will keep the liver of sulfur in mind and will still shop for some ammonia when crossing the border again (understand it can also be used to clean up tarnish on old brass).

There is some selenium in the gun blue I bought, as well as hydrochloric acid and copper sulfate. Not yet into toning but would certainly test selenium when I do.

Luka, thanks for the offer : Mat finish on the watch is really striking : That will obviously work ! Looking forward to meeting you (PM sent).

Just to satisfy potential curiosity, here is what the blades/leaves currently look like :

138276

Thanks again,

[AtlantaTerry]

Can no longer find ammonia in stores (and lost the one quart bottle that I had) :-(

Is it possible to still buy a bottle of ammonia in a hardware store in the US ? (border is quite close and I go from time to time to pick up my auction purchases).


The first place I would have looked is in a grocery store. I am curious if you tried that.

[Pierre 2]

Terry, to satisfy you curiosity : It seems Grocery stores in Quebec (as well as hardware stores) are no longer allowed to sell this, or maybe more precisely, no longer willing to sell ammonia for it now requires some sort of transport permit (as I have been told by a seemingly well informed lady in a big retail outfit). This requirement would have been in place for a few years already, hence my unsuccessful quest all over the place. Still, I may still have missed a forgotten bottle or the place were it would still be carried...

[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.