Since it is usually quite easy to remove a pearl from its peg, it
makes more sense to remove the pearl before any soldering . Removal
of the pearl is facilitated by immersing the ring in hot water for
several minutes ( make sure that there is a sufficient quantity of
water…I generally use a quart container…approximately one
liter…otherwise the temperature may not have time to transfer
to the ring.) Another approach is to heat the ring via the shank
with a torch. This latter method is a bit more risky because you may
get the pearl too hot. Using garnet sand or any other heat resistant
medium won’t keep heat from being transmitted to the pearl. However,
the problem is not so much one of burning the pearl as that of
deteriorating the glue that holds the pearl.
When remounting the pearl on its peg make sure that you remove all
vestiges of the old glue before applying the new. This is especially
important with respect to the hole in the pearl. You can remove that
glue with an appropriately sized drill bit. The glue that remains on
the ring may easily be burned off or you can scrape it off. It is
best to avoid using epoxy glue because it turns brown with age.
Magic glue ( cyanoacrylate) is also not appropriate unless it is the
special formulation for glueing non porous surfaces. It is also very
important to insure that the hole in the pearl is thoroughly dried
out if you have used the hot water method of removing the pearl.
Ron Mills Mills Gem Co., Los Osos, CA.