The authoritative public forum
  for Metal Finishing since 1989
-----

Craftmaker wants simple setup to anodize small copper objects

2003

Hi all,

I've a small crafts business in the old walled city of Derry in northern Ireland. It's a one man band - I'm the proprietor, craftsperson, and I also sweep out the place ;~). Most of my produce is flame coloured copper that I finish with a benzotriazole ⇦this on eBay or Amazon [affil links] anti-tarnish soak to inhibit further oxidation. I realize that I'm in fact anodizing by heat (using the tip of a simple butane torch ⇦this on eBay or Amazon [affil links] flame). While this technique produces quite a stunning range of vivid colours on burnished and thoroughly cleaned and degreased objects, I'm keen to produce selected interference colours by anodizing copper objects in a small electrolytic tank. The idea being to produce specific thicknesses of thin film oxides deposited on the anode connected object that will produce specific interference colours. For some design purposes I require a uniformity of colour that is not possible to achieve by the flaming method. I'd like to try some simple table top experiments to anodize a series of small copper objects and would appreciate some advice regarding an electrolyte, suitable power supply, and basic set up.

Other copper workers may wish to try a related process using a small kiln at 350C for several minutes. I've had limited success using a large potter's kiln but without an observation window it is impossible to determine exactly when the interference colours emerge.

Thanks in advance,

Michael Doherty
decorative crafts - Derry, Londonderry, Northern Ireland

I would like to know what colour copper turns when it has been anodized.

Simon West
My own research - Slane, Ireland
2006

---

2006

Well, I guess my answer at this point would have to be: It depends on the electrolyte and operating conditions you intend to use :-)

So what electrolyte and operating conditions are you contemplating?

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey