> I've got a
> couple of gal of HCl, but only a liter of 3% H2O2, and was looking for a
> way to make up
> the O2 deficit, both immediate and over time.
Well, you don't exactly need the O2.
The oxygen is not engaged in etching as i understand it.
It only "frees" the clorine from the HCl, building H2O along the way.
The clorine is free then and binds the copper.
(That's how i guess, please tell me if it is stupid)
Now, if you need no oxygen it might
just work to do some heavy electrolysis, preferably with a spinning
electrode.
(but a static one might too work - maybe a long hose filled with etchant
an the electrode
at the bottom to "solve" most clorine in the etchant.
Crank the current up until you get just enough gas to not raise too much
to the top.
Now if you have trouble maintaining the copper level (it plates) simply use
copper anode and cathode, no carbon or titanium.
If you want to reduce copper then switch over to no-copper electrodes.
The only chemical needing replenishing is HCl, and even that can be kept
low
if there is no clorine gas emission and you plate out the excess copper.
Of course you can always add a air bubbler.
Discussion on the above very welcome.
ST