Q: In older jewelry instruction books, I keep reading references to “boiling out” jewelry in a “boil-out pot”. Is that just a warm pickle pot, or something else?
A: The “boiling out” process, and the “boil-out pot” you’re talking about probably refers not to a pickling solution, but to an alkaline cleaning one. Some of us still use it, either in place of, or next to and as an alternative to, ultrasonic cleaners. In our shop, we use a boil-out pot with a simmering solution of TSP as a means of cleaning the gunk out of rings, behind stones, etc. before working on them, or as a means of cleaning polishing compound off after polishing. This would be for those times when the ultrasonic cleaner is not appropriate, such as if there is risk of losing loose stones, or with metals or stones which the ultrasonic can damage.
The boil-out takes longer, but is quite effective, and much gentler to the jewelry. It won’t shake out stones that aren’t securely set, and won’t frost the finish on cast sterling silver, the way stronger ultrasonics can do if the silver is left in there a bit too long in an attempt to remove stubborn deposits of polishing compound.
I know of one commercial repair shop that simply refuses to use an ultrasonic at all. Instead, they clean their work using a boil-out pot filled with a solution of lye, under a good exhaust vent. They’ve got another one with much gentler TSP, I think, or perhaps some other detergent, for things that cannot tolerate lye. The reason they went to this setup is that they work with a lot of silver, and got tired of having to repolish silver things that had gotten marred by the ultrasonic they’d had before.