Hello!
I am a beginning metalsmith making a multimetal piece (a fairly big
chain) and have encountered something that threw me for a loop the
other day.
The links in the chain are mostly non-ferrous metals, with two links
containing some twisted iron wire. All along I have pickled the
non-ferrous metals as usual in sparex being careful to keep the
sections with the iron-bearing links separate, no problems. I
pickled the short sections with the links with the iron wire in a
hot vinegar + salt solution I read about here, and that worked
perfectly well for those.
The problem came when I got the whole seven feet of it together and
figured that I had better pickle the whole thing in vinegar and salt
to avoid copper plating the numerous sterling links due to the two
links with iron.
I put it in a clean pyrex bowl with the hot vinegar and salt and
upon checking back on it a little while later was mortified to find
that the whole thing had a lovely pink glow!
Now, following another tip I found here I submerged it (while
carefully holding the two iron-bearing links OUT of the solution!)
in a sparex + 3% hydrogen peroxide solution. Voila, the copper came
off the sterling (and everything else) like magic very quickly. You
had better believe I stood there watching it like a hawk, though. It
went fast!
The problem is fixed but I am still very puzzled as to why it copper
plated in the vinegar and salt solution. I specifically opted for
that as a final pickle because I thought it would not plate with
iron in it! Was it the salt? What the heck was going on there? What
did I do wrong?
Thanks in advance for answers to this little mystery!
Also, I want to send a huge thanks to the list for providing so much
valuable Most recently James Binnion’s on
bronzes (brasses) and how they behave after soldering/pickling in
the last month or so- immediately helpful and useful to me. It has
made a HUGE difference in my practice and has helped me solve
numerous problems in the studio. This is an amazing resource.
Bonnie