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Copper oxidized "flames"

Posted: Sun Mar 13, 2016 9:27 pm
by winsleydale
Y'all know that finish that the metal bits of Edison Idelias and A-150s have, where it's like a mix of polished copper and black oxide? Well I am in the process of buying a house from 1928 and it looks like that was the finish on my (original copper) heat vents, but about half of them have been polished off. How can I redo that finish, or where can I send them to have it done?

Re: Copper oxidized "flames"

Posted: Sun Mar 13, 2016 11:27 pm
by De Soto Frank
I believe there are kits.

"Patina-ed" metal finishes were quite popular in the early 20th century, and more than a few well-intentioned but ill-informed people ( myself included when I was young and didn't know any better ) believe that all things brass should be bright yellow, with a mirror shine, like a new trumpet. :|


As for the creating the dark/light effect, my understanding is that the entire piece is chemically darkened, and then carefully buffed bright in spots for the lighter shades.

Also, with antique house hardware, be aware that many pieces ( door rosettes, switch-plates, heat registers, etc. ) were made from steel or iron, then plated with copper or brass, then perhaps patina-ed. In such cases, the non-ferrous plating is VERY thin, and will tolerate little polishing before going-through to the base-metal. Test pieces with a magnet before attempting to clean / polish.

Caswell plating might have kits for darkening of metals... they offer home plating kits...

Re: Copper oxidized "flames"

Posted: Mon Mar 14, 2016 3:21 am
by winsleydale
Thanks

Re: Copper oxidized "flames"

Posted: Mon Mar 14, 2016 2:15 pm
by JerryVan
Any plating shop can copper plate your items. Most can also black oxide plate over the copper. With a small buffing wheel you can then buff through the black oxide in areas to expose the copper beneath. Then spray the item with a clear coat to keep the copper bright. If the copper looks too bright, you can add a little tint to the clear coat to modify it.

Re: Copper oxidized "flames"

Posted: Mon Mar 14, 2016 4:15 pm
by PeterF
Comrade Stingleyflail, I must admit to some jealousy of your soon-to-be hardware, as I have over the past 16 years been slowly but surely replacing all interior hardware and lighting fixtures in our 1913 home with items bearing that finish. OCD much, yes I am.

Edison calls it "oxidized bronze" in catalogs, but that implies content other than copper (usually tin) and a reduction in the dark orange tint we usually see exposed in that finish. Others call it by lots of different names today, but I've yet to see a definitive contemporaneous term for the finish.

There are phono hobby people who duplicate it, but i believe it's expensive. I got a new old stock heat register in that finish for our place on ebay, so that might be a way for you.

In the meantime, post some shots of what you've got now! Are you sure the house was built in '28? That's pretty late for this finish, unless someone was using up old stock.

Re: Copper oxidized "flames"

Posted: Mon Mar 14, 2016 6:58 pm
by winsleydale
It is quite late for that finish, I was thinking that, as well. I can't verify that the house was built in 1928 but that's what the listing says. I'll try to get some shots of the registers when I go back to examine the plumbing on Wednesday.

There was another house I looked at from 1908 that had the oxidized finish on *all* the hardware, right down to the door hinges, but sadly I had to pass on it as the foundation was all but crumbling from long-term water exposure.

Re: Copper oxidized "flames"

Posted: Mon Mar 14, 2016 7:25 pm
by PeterF
Wow, do you have the address of that place, so we can look at the listing and pix online?

I so often wish that I had a way to transport some of the grand old houses of Detroit to a safer and more beneficial environment. I suppose there are many that could be had for a song.

Too late for Briggs Stadium, of course. What a grand house THAT was.

Re: Copper oxidized "flames"

Posted: Sun Mar 27, 2016 8:30 pm
by EarlH
I read in an old book from about 1910 on metal finishing that after the copper was plated and still bright, they put lacquer or shellac on in the pattern that they wanted to stay bright, and then it was dipped into whatever they used to create the oxidized finish. And that actually makes sense because it would be a lot easier, and faster than having to buff out spots afterword. It also explains how they could get patterns that don't make sense with a buffing wheel. Also, the bright parts stay that way for much longer than they would if there wasn't something over it to keep it from tarnishing.

I should have kept track of that article because it mentions that you can do it with a brush, spray, sponge, et. to get 'the desired' affect. And that different types of acids will make different colors on the darkened area. It would certainly take some practice though. There used to be a guy that did metal finishing not too far from here that really did a nice job with that kind of a finish, but he was old and just decided to pull the plug on the business a few years ago as it was going to cost too much to deal with the regulations that have been coming his way. And he couldn't find any buyers for the business.