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brandon13
21-Apr-2014, 13:02
I have a couple new brass flanges and I'd like to give them a little character to somewhat match a couple of petzval lenses. I realize matching is not really possible but any advice on chemicals to add some cosmetic age would be appreciated. thanks.

goamules
21-Apr-2014, 13:25
Hi Brandon, a worthy task. I'm sure there are some harsh chemicals that will brown brass, but I can tell you that when I was in the Navy salt spray did a fine job in just a week or so! Every brass fitting on railings, etc, had to be polished after every at sea period. They would turn brown very quickly in salt air. We became very familiar with NeverDull. I would say you could spray the brass with some salty water, from a plant mister, while the flanges sit out in the sun. Let the rain, sun, and salt work on them for a couple weeks, and see if that helps. I've also been told to handle fresh bras a lot, and your fingers will patinate brass quickly. But I'd try the salt mist and sun for a while. Worse case, it looks bad and you polish it back off.

hoffner
21-Apr-2014, 13:44
I have a couple new brass flanges and I'd like to give them a little character to somewhat match a couple of petzval lenses. I realize matching is not really possible but any advice on chemicals to add some cosmetic age would be appreciated. thanks.

Put it for 3-4 days in salty water. It will partially dezincificate and you will see the result when dry.

Pete Suttner
21-Apr-2014, 13:54
Picasso would have his children pee on his sculptures...

Andrew
21-Apr-2014, 14:27
sacrifice a goat on the first full moon following the summer solstice... in the mean time just use them and after a few goat curries they'll look just fine

Keith Fleming
21-Apr-2014, 18:30
About 20 years ago in Virginia I knew a man who cast brass buckles copied from rare Civil War Confederate packs. He said he threw the newly-cast buckles in the cat's litter box for a couple of weeks, and found the results were quite like the antique originals.

Keith

William Whitaker
21-Apr-2014, 18:42
...I've also been told to handle fresh bras a lot...

Hear, hear!

Raymond M
21-Apr-2014, 19:20
Selenium toner.

rayograph
21-Apr-2014, 19:24
Wow Raymond, nice! Good color too!

Jac@stafford.net
21-Apr-2014, 19:33
Exactly what color do you want the brass to become?

Richard Wasserman
21-Apr-2014, 20:07
Here you go—

http://www.caswellplating.com/metal-finishing-solutions/antiquing-solutions/black-brown-oxidizer-16-fl-oz.html

You must have the metal very clean before oxidizing, no oil or any other contamination. The exact color can be controlled by dilution and time.

brandon13
21-Apr-2014, 22:21
I appreciate all the advice. Even the ones meant in Jest. There are three flanges so i'm trying Garrett's salt mist and leave outside method. I might pee on one of them. I am intrigued by Richard's scientific method. I shoot all my lenses so the patina is secondary to the glass, although I do love the vintage look. Again thanks. http://brandonfernandez.com

Tracy Storer
21-Apr-2014, 22:30
In turning and machining brass I've seen more than subtle color changes happen pretty quickly, apparently from just oxidation.....handling and or salt water should give you something.
Oh, btw, HEY BRANDON !!!!

Alan Gales
22-Apr-2014, 11:40
Back when I was doing architectual sheet metal my foreman and a fellow apprentice installed a standing-seam copper roof on a very small porch over the front door of a residence. They used some chemical on it that the boss had bought to give it a nice patina. The chemical didn't really work and the customer called to complain so they went back out there and each pissed into a 5 gallon bucket and then wiped the pee all over the copper. The customer later called back all happy and told our boss how nice it looked.

Jac@stafford.net
22-Apr-2014, 12:03
Patina suggests a green colour. There are far more options, certainly better than salt crud or firearm black or brown.

Look into banana oil. Apply, let it set until it dries. Wipe it off.

goamules
22-Apr-2014, 12:08
If you had a lens with green "patina" that's verdigris, and is extreme corrosion. Normal brass patina from handling a few decades is brown. Statues are green, lenses aren't.

Jac@stafford.net
22-Apr-2014, 13:16
If you had a lens with green "patina" that's verdigris, and is extreme corrosion. Normal brass patina from handling a few decades is brown. Statues are green, lenses aren't.

Statues' patina is often the result of environmental degradation, acid rain. I cannot understand why we would want to emulate such.

Richard Wasserman
22-Apr-2014, 13:42
I used to own an antique lighting business (for about 30 years) and bought chemistry similar to what I recommended by the drum. That and various other chemistry along with assorted tinted lacquers enabled us to blend new parts with just about any old ones. I also don't imagine that the OP is looking for verdigris which can also be simulated with artist's colors if one doesn't wish to go the chemical route.

goamules
22-Apr-2014, 14:56
He's not looking for a green color, he wants the normal aged brown.

goamules
22-Apr-2014, 15:08
I also heard you can fume brass with ammonia, to turn it brown. One craftsman forum had an instruction to make brown patina that included salt water spray, ammonia, and heating. Let us know how just the salt water spray works, again that's what aged our brass in the Navy quickly, and I see online thats what a lot of craft instructions replicate too.

Carsten Wolff
23-Apr-2014, 04:05
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
24-Apr-2014, 15:41
i thought it was hot sepia toner sodium sulfide that will age-blacken brass

maybe any will do equally

Robert Opheim
29-Apr-2014, 23:30
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
30-Apr-2014, 05:27
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
12-May-2014, 10:01
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?