The mystery of electroetching

Jewelry Discussion
1

OK, I give up and throw this one out to the universe and the wise
jewelery community.

What is the mystery/secret/magic formula/offering to the gods about
sucessfully electroetching copper, yellow and red brass? I’ve read
virtually everything I could find on the web about it and still no
prideful results one could write home about. The pieces I’m
attempting have exposed surface areas from a dime to a $.50 piece
and are on either 18ga or 16ga. I’d like to get to .010 -.015" deep
on the wider lines if possible.

Ferric chloride and PnP transfer sheets work great to an extent till
undercutting kicks in, but I’d heard and read electroetching was
faster, gave better more reliable results, and chemical disposal was
much more eco friendly. I’ve used a 12v battery charger setup like
Paul Jelley wrote and diagramed about with small bulbs to reduce
current and used a regulated dc plating power supply with a choice
of either constant voltage or current. Have tried salt water, very
dilute sulfuric acid (5%), copper sulfate in 3 different strengths,
a commercial copper strike plating solution, copper chloride
solution, and some home brews that seemed to have some possibilty.
Have used heat (around 90 - 100 deg F), room temp, and agitation
(bubbles and magnetic stirrer). Voltages have stayed low on the
regulated supply (.5 - 2v) and current from.1 - .7 amps. Have used
stainless steel screen and copper sheet anodes. Distance from the
object to the anode has been from 1 - 3". All this and the resist
either erodes and/or pinholes before a comparable result with ferric
chloride. I’m begining to suspect the PnP, as a resist alone, can’t
hold up to electricity. I’m all eyes and ears to what makes
electroetching work for those of you that are using the technique.

Frank in Albuquerque

2

Hi Frank;

What is the mystery/secret/magic formula/offering to the gods
about sucessfully electroetching copper, yellow and red brass?

Your best results for etching any metal, really, are probably
achieved by a spray etching setup. This method has no undercut, in
fact, the etch slopes slightly away from the resist in stead of
cutting under it. If you are a member of SNAG, you can rent a video
set on the technique. I believe it was Billy Jean Theid who used it
extensively in her work, and Helen Shirk also. But the SNAG librarian
would know. It’s not terribly expensive to set up, and if you are
planning to do a lot of etching, it’s probably worth it. I’ve seen
amazing results, even etching to the point where the metal is
completely pierced through, like lace, which would not be possible
by bath etching since the undercutting would dissolve the entire
piece.

David L. Huffman

3

You didn’t mention if you are using a feather to agitate and remove
the bubbles and sludge during etching. Along with a close eye on the
proceeding. Also it will reduce the severe undercutting. Use of a
feather isn’t just historic. Feathers are not prone to dissolving in
acid. If you don’t have a copy yet you should check out Oppi
Untracht’s Jewelry Concepts and technology. It covers most things and
is a great source for ideas and info.

glen
been there done that !