RST Engineering wrote:

Since ferric chloride is another name for iron chloride, I'm not sure how
that would work, since there is already an abundance of iron in the
solution, but I've never tried it so I'm not going to say it won't work.
However, I'd like to hear from somebody who HAS tried it, for better or
for worse.

Jim




I've also heard of putting steel wool into spent ferric chloride etchant,
which I think gets the copper out in a metallic form and probably
replaces
it with iron. Whether that would be better I don't know.

Chris

It's possible that I have confused myself and it might have been spent
ammonium persulfate etchant instead, that the steel wool was to be put
into. I don't enough about chemistry to say which would make more sense.

The one thing I have learnt about etchant is: Don't store ammonium
persulfate etchant in a sealed (airtight) container. My bottle of etchant
burst and went everywhere.

Chris