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Posted: 4/8/2006 6:11:22 PM EDT
I need to antique some copper but everything I've found is Expensive and has a hazardous shipping charge. There has to be something I can get locally.
Link Posted: 4/8/2006 6:11:49 PM EDT
Some acid.
Link Posted: 4/8/2006 6:12:14 PM EDT
Link Posted: 4/8/2006 6:14:05 PM EDT
A natural hot spring. Seriously, some sulfur.
Link Posted: 4/8/2006 6:16:10 PM EDT

Originally Posted By Midnight-Sniper:
A natural hot spring. Seriously, some sulfur.



Sulfur and hot water?
Link Posted: 4/8/2006 6:16:13 PM EDT
Time
Link Posted: 4/8/2006 6:19:37 PM EDT

Originally Posted By superdav:
I need to antique some copper but everything I've found is Expensive and has a hazardous shipping charge. There has to be something I can get locally.



What do you mean by antique and darken? Darkening is caused by oxidation ie by oxygen. Antiquing (sp?) can be done with acids and will turn some of it green.
Link Posted: 4/8/2006 6:23:29 PM EDT

Originally Posted By superdav:

Originally Posted By Midnight-Sniper:
A natural hot spring. Seriously, some sulfur.



Sulfur and hot water?



I was in New Zealand once in a natural hot spring. I had some pennies in my swim suit pocket. After about an hour, the pennies were black.
Link Posted: 4/8/2006 6:25:42 PM EDT
Try eggs.
Eggs are high sulfur.
Link Posted: 4/8/2006 6:28:48 PM EDT

Originally Posted By Neolock:

Originally Posted By superdav:
I need to antique some copper but everything I've found is Expensive and has a hazardous shipping charge. There has to be something I can get locally.



What do you mean by antique and darken? Darkening is caused by oxidation ie by oxygen. Antiquing (sp?) can be done with acids and will turn some of it green.




Like this
Link Posted: 4/8/2006 6:30:51 PM EDT
which acids oxidize copper?

my only experiences with acids and copper ended up with REALLY SHINY pennies.
Link Posted: 4/8/2006 6:35:28 PM EDT

Originally Posted By leakycow:
which acids oxidize copper?

my only experiences with acids and copper ended up with REALLY SHINY pennies.



maybe diluted sulfuric acid?
Link Posted: 4/8/2006 6:36:44 PM EDT
Piss on it.

Or does that turn it green?
Link Posted: 4/8/2006 6:39:05 PM EDT

Originally Posted By operatorerror:
Piss on it.

Or does that turn it green?



Maybe later but probably yellow at first
Link Posted: 4/8/2006 6:42:12 PM EDT
[Last Edit: 4/8/2006 6:43:10 PM EDT by MagKnightX]
I've done a lot of work with copper. To make it black, the best thing to do is to heat it with a propane torch to a certain heat. That will turn it black-grey. HOWEVER, if you don't heat it enough it will only slightly darken, and if you heat it too much the black will flake off exposing an odd combo of pastel pink and orange and darker purples.

Also, it WILL soften it to a high degree. Discs of copper that I couldn't bend with pliers, after heating to the black/grey, can sometimes be bent with my bare hands.
Link Posted: 4/8/2006 6:52:04 PM EDT

Originally Posted By MagKnightX:
I've done a lot of work with copper. To make it black, the best thing to do is to heat it with a propane torch to a certain heat. That will turn it black-grey. HOWEVER, if you don't heat it enough it will only slightly darken, and if you heat it too much the black will flake off exposing an odd combo of pastel pink and orange and darker purples.

Also, it WILL soften it to a high degree. Discs of copper that I couldn't bend with pliers, after heating to the black/grey, can sometimes be bent with my bare hands.



That could be an option
Link Posted: 4/8/2006 7:23:09 PM EDT
Radio Shack sells a 16 oz. bottle of Ferric Chloride solution, that is intended for use in etching bare copper-plated printed circuit boards. When a piece of clean, bare copper is immersed in this solution, it gradually turns dark, over a period of about half an hour. This process is hastened if the solution is warm and/or continuously stirred.

Normally, you leave the copper in the solution until all unmasked areas are completely etched away. However, if you remove it sooner, you get a dark patina. Wash it gently in running water, let it dry, and then spray it with a protective coating of clear polyurethane, Krylon, etc.
Link Posted: 4/8/2006 7:26:40 PM EDT
www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=60864

Blacken-it is used by model railroaders to blacken copper and brass.

Doesn't ol' AFM know some stuff???

Link Posted: 4/8/2006 7:39:09 PM EDT
[Last Edit: 4/8/2006 7:42:25 PM EDT by Big_Cheese]
This may sound kinda crazy, but I sometimes work with copper alloys. (machinist) I've noticed that if you leave Tap Magic tapping fluid on copper, it'll tarnish after a few days. It seems to happen faster when the Tap Magic is put on freshly exposed copper surfaces. IE Use some super fine Scotch Brite or steel wool to buff up finish. If you want copper to look like silver, a company called Hesse makes Cyanide Silver Plating solution that'll change it's whole appearance. We use the cyanide silver plating solution to keep the copper from corroding (green) when exposed to water.
Another method is to heat the copper with a torch (rosebud) until it starts to glow and let it cool on it's own at room temp. That'll speed up the oxidation process a great deal.
Link Posted: 4/8/2006 7:48:10 PM EDT
[Last Edit: 4/8/2006 7:48:34 PM EDT by blacklisted]
Well, you can heat it with a blowtorch and drop it into some water...

If you get the temperature wrong, it will turn red or dark black.
Link Posted: 4/8/2006 8:20:12 PM EDT
I don't know how much you need, but coin collectors use this stuff. Deller's Darkener It sells for five bucks for a quarter ounce.
Link Posted: 4/8/2006 8:57:36 PM EDT
[Last Edit: 4/8/2006 9:00:47 PM EDT by dfariswheel]
When I was in high school, one senior art class project was to do a copper picture.

You pressed the copper sheet out from the back to give a 3-dimensional effect.
To antique it, you'd apply a coating of Liver of Sulfur. This turns it absolutely black.

You'd then use steel wool to rub it off the high spots to give it more depth.

You can still buy Liver of Sulfur at many art supply houses.
Here's alink to some info on using it:
www.ganoksin.com/borisat/nenam/liver_of_sulfur.htm
Link Posted: 4/8/2006 9:32:14 PM EDT
Muritic acid to strip all coatings, off, add a small amount of copper sulfate, brushed on. Without more info I think you are looking for the dull copper/ green patena.
Remember google.
Link Posted: 4/9/2006 7:13:20 AM EDT
Thanks for all the ideas now off to work
Link Posted: 4/9/2006 7:26:22 AM EDT
Everyone is talking about blackening it with heat. It's the oxygen that is doing it to a large extent. When you braze copper pipe and run nitrogen (ie 0% Oxygen) inside the pipe, it will remain absolutely the same as when you started. We do this when running copper pipe for medical gases in hospitals. If you want it dark dark brown place the object in a bag and fill with O2. If you want it black, I don't know.
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