Concerning Charles’s question about shop safety: Be careful
with alcohol and boric acid used to prevent fire scale when
soldering. I’ve worked with all manner of chemicals, acids,
torches, solders, rotary tools, hot metal, etc. with only minor
problems, but I’ve come close several times to setting either the
shop or myself on fire when alcohol dripped from jewelry or
tweezers after igniting it. The problem is that alcohol flames
are almost invisible and can go unnoticed until a real fire
starts. I once was intent on a difficult soldering task and
didn’t notice for a time that my bench was on fire. Fire
extinguishers should be standard jewelry shop equipment.
Rick Martin