On Tue, 05 Apr 2005 15:41:18 -0700, Grant Erwin
wrote:

What do you figure the reaction is that's taking place at the carbon
electrode? I guess I sort of thought it had to be a steel electrode.
Else why not just use copper? At any rate, this is my first time EDRing
and I'm doing a small piece - a steel 2" caster - and I'm just using a
piece of 3" steel square tube as the anode (cathode? boy I could never
get those straight). It's bubbling away nicely. I figure I'll toss the
solution after I'm done. The cost of a tablespoon or two of washing soda
isn't worth it.

Grant

Without going into mental gymnastics and sorting out anode, cathode,
etc., I'm guessing that either hydrogen or oxygen is being produced.
The only thing the "waste" electrode needs to do is to establish
electrical contact with the solution. What goes on, there, is
unimportant, IMHO.

If you use copper you'll wind up with some sort of copper compound. I
do believe the copper will be consumed.

Back in the days when I was believing the folks who said stainless
steel wouldn't be affected, I used a coil of tubing that came out of a
heat exchanger, assuming that it was S/S. The next morning when I
checked my vat, nothing was there! The coil was completely consumed
at the water line. The rest dropped to the bottom of the tank.

I'm guessing the thing was made of Inconel. Whatever it was, it was a
disaster in the electrolytic vat! :-)

Regards,

Orrin