On Sun, 31 Oct 2010 17:56:55 -0700, mkoblic wrote:

There was some concern about production of chlorine in the process I
was using to remove steel by electrolysis. I thought I would
investigate this further.

I made a quick and dirty set-up using steel as anode and stainless
steel as cathode (identical to the actual process). I tried it in 1%
NaCl solution and the same solution acidified with a "splash" of
vinegar. I was going to collect the gases but this proved impractical.
Thus I judged the gas production by the number of bubbles produced at
each electrode. This is what I found:

1) There was *no* gas production at the anode with either electrolyte.
Not a single bubble.
2) There was copious gas production at the cathode. This I take to be
hydrogen. I did not light it up to confirm...
3) I changed the anode to copper. Still no gas production.
3) I changed the anode to stainless steel. While there was on-going
copious production of hydrogen at the cathode, there was minimal
bubble production at the anode with some yellow discoloration. I take
this to be chlorine.

Thus with my existing set-up and given the scale of the operation,
production of chlorine does not appear to be a concern.

Why use any salt at all? Just the vinegar should ionize the water enough
to conduct well. (or a few drops of battery acid.)

Cheers!
Rich