By Raymond Jackson
In the Guild of Enamellers Journal, (Spring 2000), Dorothy Cockrell described how to build an electric etching kit and to prepare small pieces of copper or silver for etching using a weak solution of acid. It is a relatively safe and clean method of producing items for Champlevé enamelling.
At that time, I was relief etching copper using the more conventional Ferric Chloride solution. Relief etching is the eating away of large areas of metal as opposed to line etching which results from scribing through a pre-applied resist. Ferric Chloride is not a very agreeable chemical and the etching process creates bubbles and deposits and the solution must be carefully disposed of when exhausted. A development that alleviates the unpleasantness of Ferric Chloride is Edinburgh Etch. This involves adding citric acid to the solution and this speeds up the process, dissolves the sediment, creates less bubbles and the solution has a longer life.
Despite this improvement to the mordant, I was keen to try electro-etching as it uses less aggressive chemicals and it should give a more controllable etch. Starting with Dorothy's work, I have gradually progressed with this technique. In doing so, I have relied heavily on the work of Cedric Green, (see References), who has explained and identified the benefits of using copper sulphate solution as the electrolyte and the use of new resists. He places considerable emphasis on the benefits of using non-toxic chemicals for etching copper and other metals. Although his work is aimed primarily at the printmaker, much is of direct application to Champlevé enamelling.
So I have set down theses notes of my own experiences with electro-etching copper. My work is not definitive and there are many other techniques for electro-etching copper. Others embarking down this road may, nevertheless, find the information helpful.
Download the full article here: