I was always told by my Master Goldsmith that silver solder joints
were made brittle by extended periods in acid based pickles.
From observation, I would agree that this is true. My routine is as
prepare joint (clean, tight, etc)
solder (plumb hard sterling solder)
cool slightly and quench in water
TEST for strength (if it gives or fails, resolder after cleaning. If
it’s solid and I can’t budge it, continue to next step)
pickle (hot sodium bisulphate solution)
continue to next fabrication step or onto finishing process.
Example in question: complicated necklace with many solder joints -
bezel and backplate settings for cabochon cut stones and open backed
bezel settings for faceted stones - all with jump rings soldered to
settings, which were then joined together by jump rings.
Problem: Some of the insides of the cab settings had stubborn black
My proposed solution: To leave the necklace in the pickle over a
weekend where I wasn’t going to do any silver work - based on others
saying that it would not affect the structure of the piece, only the
surface. The crockpot was turned off so it was left in cold pickle
for the weekend.
Result: When I removed the piece and rinsed it, I tested the joints
again for strength to ensure the integrity of the necklace and a
number of the jump rings just came off in my hand at the slightest
nudge!!! REMEMBER that these joints were rigorously tested after
soldering and prior to being pickled and they WERE very strong.
ALL joints were thoroughly tested and the failed ones were
re-soldered and retested so all was well with the world again - but I
WON’T be leaving anything in the pickle for extended periods again.