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Caps for irregular pearls

Jewelry Discussion
#1

I bought two 10mm black Tahitian pearls while on my honeymoon last
year. I’d like to make pearl caps for them with 22k granulation on
the caps. Here’s the problem, the top ends of the pearls are a bit
oblong and have 2 little rings around them. The caps will cover
these irregularities but I’mwondering how to make the caps. Here are
the options I’ve thought up:

  • Mold the cap to the pearl out of wax and cast. - problem is I don’t
    have casting equipment and would rather not have to contract out.

  • Mold the cap out of PMC - is this even possible, considering
    shrinkage?

  • Chase & repousse the cap so it fits the pearl just right - sounds
    kind of tedious.

  • Make the cap from my dapping set and then file the oblong end of
    the pearl down to fit - something tells me it’s very WRONG to do
    this.

Are there any other options I’m not thinking of? I’ve looked in the
archives and couldn’t find much on the subject.

Thanks,
Jennifer

#2

Jennifer,

Are there any other options I'm not thinking of? I've looked in
the archives and couldn't find much on the subject.

You’ve got the right idea with the dapping tools. Normal use with
just the block and matching punches will give you a hemisphere. Then,
take a smaller punch, and over a suitably sized (smaller) hole in a
piece of hard wood, punch it again. That deepens the depression. You
can repeat this, after appropriate annealings, with smaller punches
yet, to make it longer. Just watch out that the bottom doesn’t get so
thin it starts to tear. The wood is used so as not to mar the outside
surface much. Doing this with the steel block would leave deep
gouges on the outside of the form (though this might have some uses,
if carefully controlled, since it might sort of mimic the marks on
the underlying pearl…) the end result is likely to still be a bit
lumpy, but you can planish (gently smooth with a hammer) over some
suitable piece of steel, such as the end of a curved burnisher, if
that’s the right shape, or just the shank of one of the dapping
punches. Or grind a bit of steel rod to the desired interior shape
and planish over that.

Another way to do something like this would be to start with sheet
metal, and lay out the shape for a cone with a clipped off small end.
Form it around, and solder the straight seam. Then slip it over a
dapping tool (held in a vise) who’s diameter is what you want for the
small end of your cap. form the small end of the cone with a hammer,
closing it down over the round end of the dapping punch till it’s
small enough a hole to solder or fuse shut, or hide with a jump ring
or bail, or whatever… This approach would work better if you need
a really deep form, rather than one just a bit deeper than the
hemisphere.

Peter Rowe

#3

Any and all of your options will work. Personally, when I have an
odd shaped pearl, I just use a dapping die to shape a round piece
deep enough to just cover up the irregularities. Sometimes I’ll use
smaller dapping punches to force the center out further than the rest
of the piece to make it fit better but usually with pearls of this
size there is still plenty of pearl showing even if you make a fairly
large/long cap. Filing down the pearl is fine too, especially since
the piece seems to be for you. If it’s for sale, just disclose it.
But these days people do all kinds of things to pearls (faceting,
carving, etc.) and they don’t seem to have a problem with that.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
www.spirerjewelers.com

#4

Sounds like you bought pearls with a shape best described as ‘circle
button’ … many of these ‘irregularities’ are, even in cultured
pearls, naturally formed and do not necessarily need to be hidden.

Without seeing the pearls, it’s hard to say, but from the sound of
it, I’d probably make the cap from your dapping set and, if you
really feel it necessary, file the cap a little bit.

Alternatively, does the ‘top end’ actually have to be the top end?

I work quite a bit with odd shaped pearls, and have learned that
’top’, sides’ and ‘bottom’ are more matters of perception than fact,
so perhaps a slight adjustment to the design would see the oblong and
circles becoming a stand out component of the design, shouting that
these really are ‘real’ pearls?

Good luck anyway - I just love Tahitian pearls!
Jane Walker
www.australiannaturalgemjewellery.com.au

#5

Has anyone thought about coating the end in vaseline and diping it
in wax? Might make a good cap.

#6

Thank you all for your feedback. I’ll try the dapping technique as
suggested by Peter and Daniel.

Has anyone thought about coating the end in vaseline and diping it
in wax? Might make a good cap.

Lynn, I took a workshop with Harold O’Connor once and he used this
interesting stuff that he bought from a dental supply place. They
are thin sheets of wax that you heat up, place over a container of
silly putty-like material, and dip the piece into it so the wax
conforms to the piece. He would then cast it.

Jennifer

#7 
thin sheets of wax that you heat up, place over a container of
silly putty-like material, and dip the piece into it so the wax
conforms to the piece. He would then cast it.

Jennifer, Do you remember what gage of wax the thin sheet was? And
did he do this to compensate for shrinkage?

I do some wax work and have the simplest wax pot. I’ve used a similar
technique with stones. I dop the stone and apply a very fine coat of
lubricant called ‘Kleen Lube’, a dental industry product. I dip the
stone in the wax pot to get a light coat of wax. Temperature of the
wax is important; a little experimenting is helpful. The temperature
of the wax determines how thick the wax will be.

I use an injection wax that used to be called ‘Red Sierra’ probably
still is. It melts at a fairly low temp; you could look it up. Used
with something like ‘Kleen Lube’ and a low temp I doubt that most
materials would be damaged in the process. No guarantees here; try at
your own risk.

Once that coating is cool I then coat that wax with’ Kleen Lube,'
very little is needed. I dip again. Once that solidifies the lube
makes it easier to separate the two waxes. This is my attempt to
compensate for shrinkage. With a few trials one can get pretty good
results.

KPK

#8

Hi Kevin, The wax sheets were very thin, I want to say about 28ga.
The wax didn’t seem to “stretch” too thin when he conformed his
pieces against it. The wax did not stick to the piece and you could
pull the piece off almost right away without waiting for the wax to
cool off too much. It looked like some really handy stuff, and great
for granulation. I don’t remember him mentioning anything about
shrinkage when he cast the wax. I haven’t tried the wax out myself,
only saw it in a demonstration. I’d love to try it out one day.
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