Does anyone have any hints on sizing down channel set stones?
cecilia
Does anyone have any hints on sizing down channel set stones?
Princess or rounds?
Let me say this is not for the faint of heart. You may have any in a
considerable range of complicating factors, some of which are
surmountable and some just are not.
First you need to assess what you are up against. (I’m assuming you
mean an eternity band, partials are not much different from regular
sizing jobs).
Is this ring your property or does it belong to a client? There is a
distinct possibility you may ruin the ring so speak plainly to your
customer beforehand about the risks, otherwise you may be buying her
a new ring.
What condition is the ring in? If its very worn the cross section of
metal is thinner…you have less ‘forgiveness’ in the shank when you
bend it and less bonding surface area for the solder. The rails over
the stones are more fragile and the stones may pop out. Check very
carefully for previous repairs or solders.
What stones are you dealing with? Diamonds make it easy(as far as
the stones themselves). saph/ruby are little more ticklish,
emeralds…oh brother, forget it unless you have a laser. What shape
are they? Squares or baguettes have different considerations from
rounds. Are any stones already damaged? Figure on replacing those in
the process.
What metal? If its platinum you will not be able to use plat solder,
best choice is 20K white welding if you think the stones can take it.
Any kind of karat gold…go with the hardest same karat solder you
feel comfy with.(20K white will probably burn corundum) While the
higher heat required with hard solder MAY affect your stones, the
reason I like hard solder here has to do with filling and strength.
You’re better off not to have to go in a second time to fill in a low
spot where the solder didn’t quite flow. Softer solders tend to flow
all at once and kind of overshoot the outer surfaces, whereas hard
solder gives you a little more flow point control…that is you can
manage the heat a bit more precisely allowing you to sink the ball
slowly into the join, let’s you stop before its too late. Don’t
linger at high heat too long or the solder will leave a hole. Don’t
quench!
How much of a change down? If you’re dealing with a fully azured
band there is a very definite limit on how down you can go. Sorry,
there is no magic number I could tell you but the more you go the
riskier it is. I’ve gone as far as three(with crossed fingers and a
"Hail Mary"). Simple drilled shanks are a little more flexible, but
not all that much. Remember the amount you can come down is tied
directly to the size of the stones. You are basically sizing by
removing stones, can’t remove half a stone.You may not be able to
hit the size exactly, unless you can deal with a plug or have room
below the stones to grind out the finger size a smidge.
OK so everything looks promising so far?
When you cut the piece out you basically are cutting a wedge. Don’t
aim your saw at the center of the ring(along the radius) but rather
leave extra metal on the finger surface. Instead of cutting a
(hypothetical) 15 wedge cut it at say 20, again hypothetical. Its
better to trim to fit than to overshoot on the first cut. You will
need this extra material because of the way a stone set ring bends.
You can’t just squeeze away with ring bending pliers. What works is
to gently ‘fold’ the ring with a mallet. With the cutout facing east
or west gently tap down at north. Don’t get crazy and don’t think
you’ll fully close the gap, you won’t. When that goes as far as it
will, turn the ring so the gap is slightly off north and tap the cut
end down, doing both sides a little at time til the gap completely
closes. Sometimes its helpful to do this on a mandrel with the bottom
of the ring resting on the bench to prevent going too far. If you cut
the wedge right you will have too much material at the finger
surface.
Cut this away now. I like to use a.009" separating disk. be careful,
they shatter easily, use a little bit of spreading force on the shank
to keep the disc from jamming. BTW, your top edge of the cut should
be just shy of touching the stones.
Ok solder it.
Round it out real slow on a mandrel. If you’re lucky or good, no
stones will fly out. Might be better to push the ring along from the
side than to pound on the stones. If you have a ring stretcher, that
works pretty good here too.
If this was a used ring, if all goes well, what you wind up with is
a used ring that’s the correct size. Your customer should understand
that it is still a used ring that has been stressed more than the
twenty years she wore it.
I have a way of rebuilding worn out eternity bands(sometimes they
want THIS ring, not a reset ring) that is very nearly impossible for
the layman to detect and results in a much stronger piece but the
process is my secret. Such a tease, I know.
Now, if you were talking about partial channels…then I’ve wasted
my coffee hour.
We usually add two thin sleeves (whatever thickness needed to be just
under the correct size) to both sides of the ring. Make the sleeves
thin enough as to not cover the openings of the diamonds. Solder the
sleeves in place then bring the ring up to the right size by sanding
the inside with a rotary file and sanding roll or drum. The edges of
the channel band and the edges of the sleeves are chamfered prior to
assembly so that when the pieces are soldered together this creates a
faux gallery line. If the parts are soldered flush the solder joint
will inevitably polish out and show making for a shabby finished
piece. Make sure that you clean the ring thoroughly, channel bands
tend to be packed with dirt, and make sure you take precautions to
protect the stones. This method is obviously for stones that can
withstand soldering, if they can’t, you are going to need to call
your friend with the laser. Check the stones for tightness after you
have finished, (also a good idea before you start ) the heating and
even the lasering will generally tend to loosen stones so figure on
tightening some stones in your pricing. This is much more involved
than your normal sizing job so charge accordingly.
Hi Cecilia,
Going down is easier than going up because most times the diamonds
are very close or touching. When going up they can sometimes jam each
other and chip. When going down they are moving away from each other.
That said: Use a piece of leather to protect the top channels and
stones and bend the ring gently and evenly all around the ring with
ring bending pliers until the spot you cut out is closed again. Use
extra care with colored stones.
Mark
Does anyone have any hints on sizing down channel set stones?
Don’t.
If you absolutely must warn your client that the ring will not be
round after sizing. One can remove a small amount of metal (1mm or
so) from the bottom center of the band and then bend in the lower
band ends to meet and solder. Do not bend the channel area as the
stones will pop out. The final ring shape will be a squashed circle.
Lois
www.loismartens.com
We usually add two thin sleeves (whatever thickness needed to be just under the correct size) to both sides of the ring.
Please excuse this extra question from a newbie: provided the size
difference was not too extreme, could one add material just to the
interior of the band? A ring within a ring, so to speak?
Thank you,
Lorraine
Thank you so much. You did not waste your break. I have simple been
practicing in the fear that someone is going to want this type of
ring done. I have had good luck with sizing up but one bad sizing
down. I am so thankful for your help.
Cecilia
Lorraine, that is exactly the process. Your reference to a ring
within a ring is spot on, though I am using two rings inside. One on
either side of the holes or azures behind the stones.
A ring within a ring, so to speak?
Yes, this can work but there are considerations…
What you’d like to avoid is changing the height of the shank too
much. Look at most comfortable rings and they tend to have max height
in the 2-3mm area on the back half of the ring. If you wind up with
like 4mm, its gong to jam against adjacent fingers or tend to slip
diagonally on the finger. And don’t shake hands vit Ahhnold.
On the other hand if the shim is only on the order of.010", this is
pretty thin and reduces your ability to blend sharp edges. Don’t
wanna draw blood over the knuckles.
Another consideration is now you’ll be making two long solder joints
say about 4-5 inches total length. That means a long time under the
torch, increasing the chance of toasting some stones. And you may
wind up using too much solder trying for a good fill and start
filling in some azures instead, which is messy. You could conceivably
make an insert that has pre-drilled holes aligning with each stone,
lotta work to come out right.
Something else is that now you will have two circular solder joints
on the outside of the shank. That’s a pretty good potential for
pitting and at the very least will require careful finishing. Maybe
you could hide it by graving a line but engraving over solder is
frustrating.
Sometimes shots suffice.
Repairing jewelry most often involves assessing the odds and making
reasonable predictions and sometimes just holding your breath. Pick
your poison and proceed.