Re: Copper


Bramblebush ForumsFAQ

Posted by David on July 20, 19100 at 11:32:45:

In Reply to: Copper posted by Ron Rice on July 14, 19100 at 14:40:38:

There are a number of traditional patination processes for copper. Most of these work equally well on copper alloys (brass, bronze, etc.). Here are two good starters:

1) Grey to almost black: Liver of Sulfur (available through chemical suppliers and metalsmithing suppliers): dissolve in water (one small sugar-cube-sized chunk per quart should be about right), totally immerse the copper in this solution and watch closely, the color will develop in a matter of seconds, with a full deep purplish-brown in less than a minute. I recommend using it cold, especially on copper, as the color develops more slowly and seems somewhat more durable. Of course, make sure that the metal is clean, free of fingerprints, oxidation, etc. Don't leave it in beyond the point where the first signs of a black soot-like film begins to form. If you do the oxide layer will flake off.

2) Verdigris/grey-green: Cupric Nitrate (available through chemical suppliers; talk to the folks at Bryant Chemical, they're very helpful): this requires a hot application which is somewhat more hazardous than a cold immersion process like liver of sulfur. I suggest you get a copy of "The Colouration and Patination of Metals" by Hughes and Rowe. Their descriptions are clear and thorough.

It goes without saying, in this day and age, that you should ask for MSDS literature when ordering these chemicals and follow all recommended safety precautions (i.e. eye protection, ventilation, etc.). That's me covered!

Follow Ups:

Bramblebush ForumsFAQ