There are many opinions on the best glue for pearls, and most views
have their valid points. The most important thing to consider is the
post and the hole in the pearl. Most failures we have seen have been
due to improper posting and/or fitting than the type of glue used.
Proper fit is imperative. The pearl must seat down into the cup
completely, and the fit must be tight prior to gluing. Here are the
guidelines I use for pearl posts.
First you must choose the proper wire gauge for your post. The
larger the pearl, the heavier gauge wire you should use to secure it.
You can get more leverage on a larger pearl, and if the post bends,
it gets, essentially, pried out of the hole.
For pearls up to 3mm, use 20 gauge wire
up to 7mm, use 18 gauge wire
up to 10mm, use 14 gauge
over that I use 12 gauge.
As for the length of the pearl post, I recommend no less than half
the diameter of the pearl. I generally drill between half and three
quarters the diameter of the pearl. Most pearls will have to be
adjusted somewhat, as many are drilled very shallowly or with a too
small diameter hole.
Lastly, the post must be textured to give the glue something to hold
onto. This way, the glue fills the spaces created between the
texture of the post and the irregularities of the pearl hole. I knurl
the post with my side cutter, creating a cross hatch pattern up and
down all sides of the post.
Ideally, you would use a wire material other than sterling, due to
its tendency to bend easily and then fatigue. I usually use white
gold, even in a yellow gold piece, because it is stiffer and therefor
As for the specific type of glue, either cyanoacrylic (super glue)
or epoxy will work.
If you go to the archives and type in the words "glue pearl", you
will find extensive discussions on this topic.
David E. Lee
david lee jeweler
Mason City, Iowa