I have been advised that Firescoff is the best flux to use, to avoid
a cloudy coating on the pavilion of a tube set faceted stone. It is
supposed to be better, because the coating will was off in hot water.
I normally use Cuprinol flux. Is the Cuprinol as easy to clean off as
Wouldn't the stone be set after all the soldering is finished and
most of the polishing? That's how I've tube set faceted stones. Any
flux used would washed off before the stone is set.
Bruce- Please tell me that you are soldering on diamonds not colored
stones. When soldering on diamonds we always coat with boric acid
and alcohol to protect the diamonds. Boric acid and denatured alcohol
is our go to fire coating. Both ingredients easily available and very
Do not ever put anything containing boric acid on any sapphires or
When heated the flux will adhere to the stone and when dissolved
after soldering leave the stones pockmarked. Trust me on this. I made
that mistake many many years ago and will never forget that lesson.
It was an expensive one. I've screwed up enough in this trade to
learn what mistakes to not make. I'm whatcha call "An Expert".
Have fun and make lots of jewelry