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Laser Welding


#1

All, Last year one of my customers sent me a 3 carat Ceylon Sapphire
that he had damaged during a repair. Damage that occurred on the
crown mains looked like someone had taken a pick and struck the stone
until a crater was blown out about .75 mm deep. On the pavilion
another cone shaped crater was blown out exactly opposite the crown
crater. He had been retipping the ring with laser and missed the
prong. In a flash the stone was damaged. Using concave facetting I
was able to repair the stone. Finished weight of the stone was 2.25
carats. If you are going to use a laser, Do not miss.

Gerry Galarneau
www.galarneausgems.com
@Gerry


#2
   a crater was blown out about .75 mm deep.  If you are going to
use a laser, Do not miss. 

True enough, though I suspect that to get a crater that deep, the
errant jeweler wasn’t being cautious at all, but was likely using a
fairly high power setting on the laser. lasers work by sending a
beam of infrared (heat) at whereever they’re aimed. it’s a narrow,
very precise beam. But one must keep in mind that with precious
metals, the metal reflects between 80 % (white golds) and 97& (yellow
golds, platinum, silver) of the beam, and what’s left must still be
enough heat imput to overcome the rate at which the metal can
conduct heat away (think about how fast silver conducts heat) and
still be able to melt the metal. that suggests, rightly, that the
overall power of the laser beam being used is very intense indeed.
Gemstones, being transparent, don’t tend to reflect as much, if much
at all, of that beam away. Some stones will tend to just transmit it
fairly harmlessly (diamond, which also, do to it’s very high thermal
conductivity, is also quite resistant to heat damage) and thus can
withstand a certain amount of accidental exposure. But even diamonds
are easily blasted, if one uses any but the lower power settings, or
if the beam really hits it straight on, rather than a glancing, low
angle hit which is more easily reflected away. Some colored stones
are more sensative than others. Red colors, being more likely to
transmit infrared, seem a little less sensative than blues and
greens, which are more likely to be opaque to reds and infrared
colors, especially in darker tones. Sapphire is indeed fairly
sensative. tourmaline is extremely sensative. And it’s not just a
matter of not hitting the stone directly with the laser. it’s also a
matter of not letting all that aformentioned reflected energy that
bounces off the metal, from then hitting the stone. One has to pay
close attention to which directioy you’re shooting the laser, as
regards where it’s going to reflect from the weld area. Learn to
think like a pool player planning bank shots… And if one isn’t
sure, either unset the stone, or provide some sheilding. Unlike
torch work, where you want thermal absorbsion, shielding in laser
welding is just something to block or reflect the beam. A bit of
polished silver sheet, maybe 24 or 26 guage, can refelct a lot of
laser energy. Or, we often use a bit of fimo. I like the dark royal
blue colors, which are then easy to see where you’ve put them, and
which, I feel, may be more opaque to the infrared than some other
colors. Make sure you’ve got a thick enough layer. I like at least
about a half millimeter layer. Reflected energy from the laser will,
of course, cook, cure, or sometimes even char the fimo clay. But it
seems pretty effective at blocking the stray energy.

Hope that helps.
Peter Rowe


#3
Using concave facetting I was able to repair the stone.  

Gerry: This is something I’ve been curious about for a long time. How
does one facet any concave surface, let alone one .75 mm deep? I
guess this question is a little like asking “How long is a piece of
string?” (Answer: twice as long as half of its length.) What sort of
tools are available for this?

Michael Conlin


#4

Gerry, Steve Kretchmer told me once that he uses the fact that lasers
can damage gems, including diamonds, to break out tiny diamonds from
deep flush settings. Since the tiny stones aren’t worth the labor to
try and save them, he just aims the laser and zaps them. They just
"blow up," in his words – and when the repair work is done, he puts
new diamonds in. He says he hates the idea of destroying diamonds,
but the metal work saved by simply destroying itty bitty stones is
far more valuable than the stones themselves.

The laser has been touted for so long as a miracle tool, I think a
lot of people don’t realize that damage can still occur. But even the
laser has limitations. Thank you for pointing out one of them, and
thank you to Peter for offering a solution! And for those who may now
be nervous about lasers: remember that all forms of jewelry repair
carries risks. You can burn stones with a torch, you can break them
unsetting them, or you can accidentally zap them with a laser. (You
guys probably have a lot of stories about what can happen! Anyone
want to share their worst moments, just for fun?) I guess it’s just a
matter of selecting which method offers the biggest benefits in
relation to the risk.

Suzanne
Suzanne Wade
writer/editor
Suzanne@rswade.net
Phone: (508) 339-7366
Fax: (928) 563-8255


#5
You can burn stones with a torch, you can break them unsetting
them, or you can accidentally zap them with a laser. (You guys
probably have a lot of stories about what can happen! Anyone want
to share their worst moments, just for fun?) 

or me it’s a toosup. One of the worst was WAY back when, as a
college junior. I’d started in jewelry still in high school both in
the H.S. silversmithing class, and with a part time job at a local
rock shop. The owner thereof gave me a large (about an inch and a
half long, perhaps an inch wide) freeform shaped opal cabochon that
he’d cut, to be set into a gold bolo tie that I was to make. Burnie
had like one I’d made for my dad with an also large, but much less
fragile or valuable stone. I’d cast a mounting with a wax wire
under frame, a bunch of decorative stuff around the outside, and lots
and lots of little wire prongs with balled up ends. To set the stone,
just bend in those balled up ends till the stone was tight. Stone
setting experience at that point, almost nil. Needless to say, the
thing didn’t survive, but ended up in two halves. As the first
really large stone worth more than a few bucks that I broke, it was a
horrible feeling. Burnie took it in stride, confiding that he’d not
paid much for the rough, then suggested an addition to the piece, a
decorative ribbon across the center, which would hide the seam
between broken halves when they were back in the bolo. It worked
fine. I’ll never know whether he was telling the truth when he said
it wasn’t worth much and that he wasn’t upset. Probably, but I’ll
never know.

But one I DO know about was probably one of the more costly stones
I’ve ever broken. this was about six years ago. We’d had another
very fine jeweler make up a nice platinum mounting for a large (8 ct)
ceylon sapphire, a nice heart shape. That got sent to a setter who
first set the sapphire in it’s center bezel, and then pave set a
bunch of mellee diamonds around it. The setting looked nice. then i
had to size it when the customers finger turned out to be a tad
smaller than thought. That too worked ok, but I noticed that the
setter, when drilling the top plate for the pave work, had nicked a
couple of the prong wires where the bridged between the upper and
lower gallerys. You could see the dings. I determined that I could
flow a little white gold easy solder into the nicks to hide that
damage. I did everything right. Well, almost. The ring got some
boric acid coating, of course, and with a tiny flame I flowed the
solder. I didn’t bother heat sinking the sapphire, since I was being
careful not to direct the flame anywhere near the center stone. In
fact, the boric acid on not just the sapphire, but it’s bezel, never
even began to melt, remaining in it’s white powdery state. but the
couple hundred degrees the stone did reach (and might have so done
even with just a blast from the steam cleaner) was, it turned out,
enough to cause expansion in the fluid filled inclusion, quite
large, in the middle of the stone. The thing was barely visible, and
then only with a loupe, but it was very large, actually, and neatly
split the stone in half. I heard that quiet little snap sound just
as that white gold solder flowed. didn’t realize till I got it out of
the pickle just what it had meant. You don’t want to know what the
replacement stone, not to mention remaking the mounting, cost us…

which, I suppose, brings us back to the argument of garnets not
taking heat, and only diamonds, sapphires, rubies, etc, being
traditionally allowed some heating. Truth is NO type of stone is
always immune. Including diamonds.

and Susan, yes the laser is very efficient at blasting out damaged
diamonds, or those that will soon be so, due to needed repairs on a
ring. With other stones, the setters usually just use the hammer
handpiece. but with diamonds, we blast em out. Great stress
reliever. makes quite a loud popping noice too.

Peter Rowe


#6

Peter, I’ve never had an opportunity to use a laser welder and not
sure I ever want to.

I do have a horror story (well almost) to relate. About 25 years ago
I was doing a LOT of repair work. My thought was…if you can repair
em…you can make em. I learned a lot during those years.

One day I took in a beautiful ring with a prong set black star
sapphire center stone and about 15 diamonds around it. One of the
prongs had come off and the customer wanted it replaced. I reasoned
I could heat the area of the prong without getting too much heat on
the sapphire and only on a couple of the diamonds.

I don’t know what solder was used to make this ring but it must have
been super super easy because, I no more hit the area with a small
flame and almost the entire head fell apart. I did a double take and
checked the metal…it was 14K so it must have been the solder. In
the end, I had to take the entire head apart, clean each piece of the
old solder and reconstruct it all over again.

It took me hours…but the customer never knew it! Hope I never get
one of those again.

Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry. @coralnut1


#7
   Peter, I've never had an opportunity to use a laser welder and
not sure I ever want to. 

Trust me, Don. If you ever get the chance to play with a decent
laser welder for long enough to get the feel of the things, you’ll
find that not only do they make some tricky work very easy, but darn
it, the things are FUN to use. Kinda like work mixed with a video
game. Well, maybe not quite, but heck. they really are very cool
tools. The main thing to remember is that they are NOT the same as a
torch. They do some of the same things, but they do it differently.
sometimes a lot better, sometimes not as good. It’s a little bit
like any new technology or tool. At first you wonder why you need
it. Then you find, if it’s a good idea, that you’re increasingly
using it instead of lesser older methods. the laser doesn’t replace
existing technology, but it sure as hell is a dramatic increase in
our arsenal of methods and tools. For most work, you can continue to
make jewelery as you’ve always done, if that’s your wish. But there’s
a whole world of things you don’t even realize, yet, that you could
do with the laser that you cannot do now, by any means. Until you’ve
got one, those potentials are not always obvious.

Peter


#8

OK guys, OK! I guess I was in one of my “I like the old way” moods
that day. Usually I’m all for doing things faster and better. What
you say all makes sense. Now tell me, are laser welders expensive?
Cheers from Don at The Charles Belle Studio in the part of SOFL where
we haven’t had rain now for two weeks and where simple elegance IS
fine jewelry! @coralnut1.


#9
Now tell me, are laser welders expensive? 

Hi Don,

The easy answer is, “Yes!” Heck, to me, a fusion welder (i.e.,
Sparkie II) is still expensive. A laser welder might be in the
neighborhood of 20x that price, but I understand the prices are
coming down.

On the other hand… there’s always another hand, isn’t there?!? If
I found myself in another segment of this business, I could easily
decide it was too expensive not to have. I can’t imagine the impact
it would have on the business of an independent contractor who does
piece work for a number of jewelry stores. I’ve never leased a piece
of equipment, but if that was my line of work I’d seriously look into
it.

As always, “expensive” is a relative term. I know rich people who
are always broke. They’re just broke on a different level. :wink:

All the best,

Dave

Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com


#10
Now tell me, are laser welders expensive? 

Well, there’s the rub. And it’s a biggie.

The cheapest I’ve seen in a new machine, well a demo, actually, is
around 22 thousand (and that’s a dealer demo). Most of the current
models list over 25K, with most of em closer to 30K. However, I’ve
seen used, reconditioned older models selling for 15-18K. My own, is
a five year old Siro lasertech ALS-35S, which I got as a tradein unit
when a factory in India upgraded. It was obvious used quite a lot
before I got it, and still cost me, with shipping, over 17. But as
more and more shops get them, some will also be upgrading their
earlier models, and other folks may find the lasers don’t actually do
what they thought. So I think you’ll find more and more used machines
on the market over the next couple years. Plus the manufacturers are
also bringing out smaller 'benchtop" models, which are less costly
new (still over 20K, though). These are not continuous duty
machines, but fine for small stuff, repairs, and less demanding use.

The thing to keep in mind, regarding the price, is that if you
finance it, you can get a machine that’s costing you less than 500 a
month, which is 25 dollars a day for a five day work week. If you
save an hour a day with the thing, it’s more than paying it’s way.
If you use it much, you’ll easily do better than that, and make
money with it.

Peter


#11

Hi All, I have a questions for Peter and the rest of you using laser
welders. I have had’ my Rofin Laser Welder for a month now and
absolutely love it. A great tool for eliminating a lot of headaches.
My question is, How do you avoid pitting when laser welding White
gold? I believe its caused by the zinc being vaporized by the laser
beam. I have started using 18k white 28ga and that is helping, but
not solving the problem. Also, when laser welding silver, I am using
a black sharpy to cut down on the reflection with silver. Do you
guys/gals have any other suggestions for minimizing reflection.

Thanks,
Kevin Fertenbaugh
Hakso Jewelers
www.haskojewelers.com