Hi Everyone- I am making a bunch of silver rings, and held one
together with binding wire while soldering. I remember to take the
wire off before I put it into the pickle. The ring turned a very
strong copper color and was quite tough to remove. I then decided to
incorporate this into a few ring designs. My question is- what is
this process called? Is this now a Patina? Thanks! Cherie
My question is- what is this process called?
In essence, it’s electroplating, though not especially controlled.
What happens is that when you use older pickle, if there is iron IN
CONTACT with the silver when it goes into the pickle, when the iron
dissolves in the pickle it forms an electrolytic cell, which allows
the copper to plate out onto the silver. You could do the same with
a bit of copper sulphate solution and a battery. You’re thinking of
course, that you removed the binding wire, right? Chances are,
there were traces of it, perhaps iron oxide that stuck to the metal,
maybe held there by the flux residue. That’s all it takes. One
solution is to use cleanly mixed new pickle. Without copper in
solution in the pickle, it won’t turn copper color since there’s
nothing to plate out on the silver, even if there’s some iron or
iron oxide still stuck to the ring.
If you wish to remove it, again start with freshly mixed pickle. If
it’s fairly strong, it will actually slowly dissolve the copper on
it’s own (copper is soluble in sulphuric acid, and pickle is a
sulphuric acid salt. But it’s slow. To speed things up, at some
peroxide to the pickle. It acts to oxidize the copper, which then
quickly dissolves.
Is this now a Patina?
Sure. Why not. If it’s a finish you like, then go with it. Just
understand what it is: metallic copper plated out on the surface of
your silver. know too, that it may darken quickly if left there,
and may not always be predicable in it’s adhesion to the silver.
The fact that it darkens, though, may be useful, since it will give
somewhat different coloration with standard patination like liver of
sulphur, than would be obtained with those methods directly on clean
silver.
Peter
I think that this would be classified as plating, rather than a
patina. It is copper color because the iron in the binding wire
actually caused copper to deposit on your silver.
Lee Einer
Dos Manos Jewelry
http://www.dosmanosjewelry.com