Hi David, Thanks very much for the explanation. Now I see where
you're coming from. It's not, or at least not primarily, that 18K and
14K yellow gold react so differently to depletion gilding, but rather
just a different approach to the process.
A couple of comments:
I let the article cool before quenching for two reasons. One: I'm
less likely to get spattered with hot acid.
I took a workshop with Charles Lewton Brain a few years ago on fold
forming. We needed a whole bunch of annealed squares of copper and
when Charles saw how we were quenching the pieces, he gave us a quick
His advice was to quench fast and quench deep. In other words don't
toss the piece into the pickle ( whether hot or cold); instead hold
it in tweezers and plunge it quickly and deeply into the liquid.
When you do it that way, you get a more even result and without
splash. (Charles, if I'm remembering this incorrectly, please
... dipping a hot article in acid eventually heats the acid up and
hot acid makes me more nervous still.
One of the advantages of Sparex and similar pickles is that they're
mild enough that you can dip a finger in them without ill effect.
Not that you'd want to do that, of course, and you'd certainly want
to rinse in water, but it happens at times. I'm sure I wouldn't be
so sanguine if I used stronger acids!
I wouldn't claim that my technique is necessarily an improvement
over the typical depletion method but it seems to work nicely on
the small articles I work on, especially the intricate filigree
As you said in the beginning, whatever works!