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Flush setting reponse from Peter Rowe


#1

Hey everybody thanks for the setting tips and pricing metals
too. I got this long response from Peter Rowe on setting diamonds
flush I thought I’d pass it on to all of you. >From Peter: First
off, you can probably forget what you’re doing with cutting
seats. It’s not like prongs, but like in bead setting. You use
either a ball bur or a bud bur (especially the shorter and fatter
bud “A” type instead of the long slim ones) to cut a hole into
which the diamond can be litterally jammed. You want it to be
pressed down tight enough so you can turn the piece back over and
rap it on the bench and friction will hold the stone in place.
You used a slightly larger-than-the-stone ball bur, so the stone
is jamming into a tapered hole, thus the tight fit. If you use a
ball bur, be sure the bottom of the hole is drilled out large
enough so only the girdle is touching, not again underneath near
the culet. I often cut the hole with a ball bur, and then open
up the back of the hole a bit more, (still from the top) with a
small bud.) The whole preference for ball burs is simply that
you don’t have to be careful to hold it vertical (even almost
sideways works just as well), and their the cheapest burs around,
so I’ve got lots of em. It’s not that they do any better job…

Once the hole is cut, pick up the stone with a little saliva on
the end of a flat ended brass rod, set in a graver handle. A
piece of sprue rod, tapered down to about the size of the
diamonds table, is about right. Brass is used as it’s soft
enough you can press on the diamond fairly hard and not break it,
unless the diamond is badly out of round or otherwise dangerously
thin girdled or flawed. Anyway, use the brass pusher to push it
down and level it at the same time. You want about a half
millimeter of the wall of the hole to extend above the girdle.
You can use a bit more, but then you’ll have to work harder. For
small melle, like say, .02 cts, or so, this puts the table about
level with the surface of the metal.

Now put away the damn gravers. Forget em. Wrong tool for this
part. Ok to trim up later, if you’ve buried the stone in too
much metal, or your burnisher is rough or something, but you’ve
only got very little metal to work with. Don’t cut it away, or
you’ll loose the stone again.

Take a scrap bur. High speed is better if you’ve got a dead
one. Cut or break off the dead working end so it’s just a
straight shank Put it in a chuck and turn it against a fine
stone, at an angle to cut an angled bullet shape on the tip,
about 70 degrees or so. You can use blunter, about a 90 degree
angle, for some work, but 60 to 80 degrees at the point seems
about right for me. It can be slightly curved as well, just
like a bullet point. Repeat against fine emery, and crocus cloth.
Then take it to a buff and put a very high polish on that tip,
without blunting the point. If you’ve got lapidary equipment,
then make this tool out of a carbide rod, or broken carbide
circuit board drill instead. (You need the diamond polishing
wheels or compounds to do this in carbide. Small, mandrel
mounted versions can work, but are slower and a lot less
convenient than full sized equipment) It’ll last longer and be
easier to use as well. Note that unless you’ve got the equipment
to quickly repolish the point, the carbide makes little sense.
You’re gonna need to redo that tool tip every dozen stones or
so. I make up about a half dozen of em at a time, and swap as
needed. The carbide burnisher, by the way, is also a wonderful
tool for polishing small details on platinum. Nothing else, even
compounds, gives quite the same result on platinum as quickly
and easily as a highly polished carbide burnisher. For that use,
you can make the tip a considerably slimmer angle as well.

The burnisher can be mounted in one of those chucks used to hold
beading tools, or any other convenient handle from which you can
easily remove it to swap in another, or to reshape when needed.

Use just that burnisher to rub down the sharp inner edge of the
hole the diamond is set into. Start at a slighly shallower
angle, and work the angle down to about 45 degrees. If you’ve
got it right, at about that point, that inner burnished surface
will tuck tightly down against the diamond. It should hold only
a little bit in from the girdle. If it goes a large distance up
the crown, hiding much of the stone, then you set the stone too
deep, and can use a graver to trim out some metal. But with a
really good polish on your burnisher, you’ll get a better finish
on that metal than any graver can give you. And that’s saying
something. Cause a well sharpened graver can give you one hell
of a crisp cut on gold. The reason, though, is that you started
with a very round hole, and a very uniform depth. with no metal
being removed, you almost have to produce a very uniform
burnished edge by the time the edge has been brought down to the
stone. With a graver you have to manually be sure to stay even
all the way around, and with tiny stones, that’s sometimes harder
than it sounds.

While doing this of course, the tip of the burnisher is gonna be
rubbing against the diamond. Needless to say, this quickly
dulls that tip. You can, with larger melee, simply take a
diamond file and file a slightly angled flat across the damage,
allowing the leading sharp edge you create to still be
servicable. In fact, with larger stones, this can help get the
burnished surface even, as you’re then using a wider curve on the
burnisher (farther up the original cone shape) to press the metal
down. But you’re also then pressing harder to move the metal.
It isn’t long before you’ll quickly decide to repolish that
point. The pressure is against the metal, not much against the
stone, so the stone isn’t much in danger from this. With
diamond at least. With colored stones, you must become
exceptionally carful, especially with a sharply pointed
burnisher, and even more so with a carbide one, to not scribe the
stone. I usually don’t risk the carbide burnishers with other
than diamonds. And usually with colored stones, I’ll use one
where I’ve not only put that little flat across the tip, but
polished it as well, so there’s no sharp point rubbing the
stones. But it’s not as easy, and often too risky, to get small
stones burnished in with the metal truly down flush and gap
free. Larger stones you have more room to work with, and can use
broader, less dangerously sharp burnishers, so you have more
leeway.

If you want sandblasted backgrounds, when you blast the surface
after setting (unless you’re really good, it’s next to
impossible to set any number of stones this way without at least
once slipping with the burnisher and marking that fragile blasted
finish, so I usually blast after the stones are set) you’re gonna
find those beautiful reflective surfaces all messed up. If you
can figure out some way of effectively masking the stones, do it.
I’ve used nail polish with little success, and little circles
(cut with bezel closing punches) of masking tape with better
sucess. Otherwise, you’ll need to run the burnisher once more
around each stone after blasting. This is rather a pain in the
ass, after all that work initially, but I’ve not found a
consistant way to cleanly mask those settings. If you’ve got a
good substance that can be easily painted on each stone and
reflector, that will withstand a bead or sand blast, please let
me know. Obviously, this is less of a problem with stoned,
satin, or other controlled textures, which can be applied
carefully enough to avoid the stone settings.

THAT WAS METHOD NUMBER ONE, AND THE WAY I PREFER. (Cause I
think the results are better)

More common is to use a flat or very slightly domed hammer
handpiece tip on the flat of the metal around the seated stone
(seating the stone is the same). Hammering the metal straight
down, the surface around the stone will bulge inwards slightly,
permanently trapping the stone. Then a graver can be used to cut
a reflector around the stone, but don’t cut that reflector all
the way flush with the stone, because chances are, you didn’t
hammer the metal down that far, and if you actually cut it away
till the cut is flush to the stones surface, you’ll find that
you’ve cut it all the way back to the girdle, and guess what!!
The stone fall out.

You can also mix these methods. Hammer set the stone, use a
grave to cut most of the metal away, then finish with the
burnisher, cleaning up the reflector better, and without the
little marks from starting and stopping the graver cut as you
work around… With larger stones, which you might need to set
deeper into the metal if you want a flush set table, you probably
will have to use the hammer this way, as there will be just too
much metal to burnish it all the way down. Unless you’ve got
stronger hands than I do…

The big disadvantage to using the hammer is that now you’ve got
to deal with that depression and messed up surface that you got
from hammering into what would otherwise have been the final
outer surface surrounding the stone setting. In a nugget design,
this probably doesn’t matter, In a beautifully flat lapped
surface, it’s a disaster.

By the way, Steve, I think I mentioned that I set tube set
diamond this way as well, so I might as well include that tidbit
too.

With diamonds being able to be soldering into place, I usually
set small diamonds in tube before cutting the length of tube off
the stock. I reposition my flex shaft motor on my left, down
low, so the handpiece is held in my left hand, pointing up. The
tube is in a number 30 handpiece, with maybe an inch or so
exposed (or less, if you’ve got too short a piece.) The end of
the tube must rotate true, or near to it. You can also solder
cast or die struck bezels to the end of a brass rod, and if you
can get them centered, also mount them this way. Spun in the
handpiece, with the end of the tube (not the handpiece chuck)
running against a beeswax or burrlife lubricated notch in your
bench pin, you’ve got a hand held lathe. A ball bur or setting
burr held in a hand chuck can be used to cut a seat for a diamond
(the burr doesn’t turn. The tube does) Don’t cut it too deep.
The diamond only needs to be flush, or about 1/2 mm below the
tube edge at the girdle. It won’t look like enough, often. Again,
a tight fit is better, but less crucial in this case. Now a flat
prong pusher or other flat ended steel tool can be pressed
against the spinning tube edge, and rocked up, to fold in the
whole outer edge of the tube at once, in one motion. Be careful
to get it down enough that the metal is flush to the stone, but
don’t squash it. You can easily thin it out to next to nothing,
but much higher up the stone, if you press too hard. Use a loupe
to check along the way. If you’ve got it right, a momentary
touch with that point burnisher on the now somewhat rough inside
edge of the tube will bring it down to a nice tight reflector.
Doing this under power like this destroys these burnisher tips so
fast it isn’t funny, but what the heck. With diamonds, you won’t
hurt the stones, only the tools. If you need to trim back the
metal, a sharp flat graver can also be used against the spinning
inside edge. Works very well, but as you’d expect, trashes the
tip of the graver each and every time. You have to resharpen for
each stone. As before, be very carful no to cut away too much.
Can happen in an eye blink. Once the stone is tight and the
inside edge tucked down bright, you can either finish the top
outer edge again with the burnisher, bringing the top to a high
polished clean edge, or spin a beading tool against that top
edge. Your choice. Your beaded top edge will come out a lot
more uniform this way than you can easily get with small diameter
settings if you have to move the tool around the tube instead of
rotating the tube.

One downside to this method is that then you’ve got to solder
the tube in place, which sometimes can loosen the stone setting a
little again, due to uneven thermal expansion rates between the
white gold and the diamond. So check the diamonds again after
soldering, and snug down again with the burnisher if needed.
Still simpler than doing the whole setting job after soldering
for many situations. Mind you, there will be plenty of designs
where you’ll still want to set the more traditional way, after
the settings are assembled. But this is a cool addition to the
technique arsenal, and sometimes a real ass saver. For me,
especially, working for a lady who just loves to accent things
with nice high tubes capped with a .02 or .03 melee…

The other downsides are that you now have to be more careful
soldering those tubes, to avoid oxidation. Harder to clean with
the stones in place. Use batterns type flux, not the white paste
fluxes, with white gold. And as mentioned, this technique grinds
up point burnisher tips so fast it itsn’t funny. Make a bunch of
em at a time. Also, though you can, if you’re careful, manually
burnish in colored stones like rubies and sapphires, don’t even
think of trying to run a burnisher against a power driven stone
on that inside reflector surface. If you need to set color like
this, use the power to close the tube up, but don’t power burnish
the inside edge. Instead, lightly bright cut the inside edge
with a graver (manually, not under power), or manually burnish
very carefully. And remember that even sapphire and ruby can
sometimes be damaged by soldering the tubes to the rest of the
piece, even if you’re being appropriately careful. It’s risky at
best.

Let me know if you need any visual clarification of what this
looks like or what the tool looks like. I recently got a little
casio qv-10 digital camera, which does decent close ups, though
not high resolution. I can easily shoot you over a j-peg of the
burnisher or some pieces I just set this way if you need.

Hope this helps.

Peter Rowe

Art Jewelry for Conscious People
http://www.opendoor.com/stephensdesign/crystalguy.html