Hi David. Thanks for the reply and link (which I am saving), as well as the details for the mordant. I appreciate that your information is the result of much research. I also enjoy the research and experiment part of trying new things. Problem is, with so much information, some of it is contradictory... and then I am left wondering what is right.
Perhaps the reason I have so much by-product to deal with using the salt water/power source method is that I am etching deep and relatively fast with it. Makes sense.
In 1992, Robin Casady demonstrated the use of Sparex (bi-sodium sulfate) for etching copper. His set-up was two D-cells, Sparex in a beaker, beaker sitting in a warm water bath in an ultra-sonic cleaner. This would provide both agitation and warmth for the etching solution. At the time, most of us who watched that demo decided that the Ferric Chloride that we had been using was "safer" and easier. Now that I am experimenting with a power source (in place of the D cells), I am back to reading Robin's instructions. Having less to take to hazardous waste disposal place is becoming more important to me.
Coral Schaffer, author of a book on the topic of etching metal for jewelry, uses the Sparex as her preferred method of electro-etching. Perhaps because it is readily available in most jeweler's studios, and there isn't the by-product to deal with. This excellent book covers many methods and mordants. There is an invaluable chart comparing safety, cost, disposal, ease of use of the various choices. However, I don't remember much info on the by-product issue. Might have missed that.
Available from
www.enamelworksupply.com
