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Laser welding hollow jewelry


#1

Good Morning Orchid,

I started working part time as a “jeweler” in a local mall store
where we specializes in jewelry, watch & electronics repair, (cell
phones, iPads, etc.). I don’t touch the electronics or watches other
than to check the movement, change out batteries, lube the seal, blow
out dust, size a band, replace a broken pin-stem, etc. I am no
watchmaker and leave much of that to the watch tech. My job primarily
is working as “the jeweler”. I am learning FAST there is a huge
difference between being a “Jewelry Artist” and a bench jeweler and
repair tech! It’s a totally fun job to do only 2 days/week but it’s
often “trial by fire” as I’m the only jeweler on duty, having been
specifically hired so the other jeweler can actually have days off.

There is much to learn about repairs and pretty much I teach myself
as I go.

Most of it is very easy stuff: repair/replace broken findings, retie
pearl strings, re-tip prongs, order & reset a lost stone, etc. I
won’t touch anything I’m not confident I can do, and have had to
leave a couple items for the other jeweler to fix when she returns,
which makes me feel bad for her. Things I need to learn include
repair/replacing channel set baguettes, fixing those nasty little
"melee"or"bead set" tiny stones when they are set in those huge flat
jewelry pieces, (God I hate those!). Most of the work is not at all
difficult, but sometimes it can be challenging. Perhaps someone can
recommend some sort of bench jeweler’s repair manual?

But specifically, I’m looking for tips & tricks concerning the use
of the laser welder, especially on tiny chains and hollow-formed
jewelry.

We have an “iWeld Benchtop” laser with microscope to use for our
repairs and I am learning to LOVE it! I’m so much less worried about
stones when re-tipping prongs and sizing a ring is now done so fast
on the laser with very quick cleanup. I am very new to laser welding.
I was given samples or “practice pieces” in the different metals to
learn on before they turned me loose on our customer’s jewelry and
was quite surprised at how quickly I picked it up. But I do struggle
sometimes, especially with tiny box chains, on the hollow links in
twisted ropes and with those damningly thin hollow formed rings,
(seriously I don’t even know how the customers aren’t collapsing some
of this stuff, it just feels/looks like junk jewelry to me!). Lately,
we are seeing that many of the new Figaro chains are now hollow made,
too. I am certain this is a direct result of the high price of
precious metals.

Last week a few rings came in for re-sizing. They looked to be solid
but turned out to have very thinly walled hollow shanks, even the
very back of one ring shank was hollow. When it was cut on the sizing
jig it collapsed the edges, making a flat mess & needing even more
repair time because of it.

Fortunately it was not me who made this error, but I was the one who
had to fix it.

Recently a ring came back to us to be fixed for a second time
because it literally tore apart next to where it was welded after it
was sized by the tech I replaced. I THINK the previous jeweler had
pushed the ends together and held it closed then lasered it, creating
a pulling tension or stress in the shank, and perhaps this can
explain why it tore apart? I am just guessing here, as it was before
my time. What I did to fix it was to clean the edges so they were
totally flat, (replacing the torn metal with a new piece), then
carefully bent the shank together much like I would a jump ring, yet
making sure there was no tension in it. Then lined the edges up
really well and finally laser welded it back together. I struggled
with the thin hollow walls though, and it was difficult to find a
laser setting that wouldn’t blow through.

The iWeld does have some “presets” available, and I use these as a
guide, but I often still have to turn down the volts and can still
blow through a wall causing a need to fill in with laser wire. Can
anyone make some suggestions about laser repairs, especially hollow
jewelry, or perhaps guide me to any articles, manuals or posts
concerning these issues?

Sorry to be so long winded!
Best,
Teresa


#2

Hello Teresa,

Laser and pulse arc welding techniques are similar. Perhaps when the
previous jeweler held the shank ends together, the weld only closed
the outside of the seam. I do a lot of repairs on sterling match
safes. They can be made of extremely thin material. Even so, I use a
graver and carve a “v” in the seam and use wire of the same alloy to
fill it in. The entire thickness of whatever split or seam you’re
welding must be filled throughout the entire thickness. Also, before
filling a split seam, make sure to clean out all of the old solder.
You can see the techniques I used on repairing a match safe with my
pulse arc welder here: http://www.ganoksin.com/gnkurl/ep7z5d

Best of luck,

Jeff Herman
hermansilver.com


#3

Teresa, laser welding hollow is one of the most difficult laser
welding jobs. Thin hollow can be a nightmare.

One technique I learned was to let the edge of the damage melt back a
bit, so that it “thickens” the metal in this area, and then gradually
fillthe damage, by building up the edges of this melted back. I start
at as low a setting as I can get that melts this metal, until I have
filled thedamage, and then I raise the voltage once there is no
longer any hole. This allows me to really fill the area, and build it
up slightly, so that I can file and finish.

At times I have to go back and refill some pitting in the repair, and
when I do so I need to pay close attention to NOT blowing through the
area again.

I find laser welding such difficult pieces of jewelry to be more of
an art form, and each job takes time, and thought. Good luck.


#4

Hi Resa Jo, The trouble with talking about laser welding is that
there are so many variables. You can adjust the beam diameter, time
and intensity in many different combinations and still get similar
results, that makes it hard to suggest settings. Then the material
you are lasering can react very differently depending on the alloy,
angle of the shot and reflectivity and color.

An easy rule of thumb is to always try to get maximum penetration
with minimum carbon build-up. You want your welded seam to be fully
liquified all the way through, but also to remain clean and shiny as
you work through it. So adjust your settings accordingly. If you
don’t you start getting that slap-slap sound and you are likely
creating a pitted weld that is filled with black carbon. Something
to remember is that lasers can often create a brittle joint, so I
still prefer to solder whenever I can. When the seam will take a lot
of stress, I feel much more confident about both the solder moving
through the seam fully via capillary action and the fact that the
heat from soldering anneals the area around the seam helps prevent
stress on the seam. Although I’ve had a laser since 1995 and love
it, I using it primarily to speed assembly, where I tack things
together so they are straight and then solder them (except for
platinum, which is perfect for the laser). As you said it’s fantastic
for retipping, great for many repairs, fixing pits, polishing. on
and on. I have never regretted buying one.

A couple of tips are to use zinc free yellow gold wire and palladium
14k white wire, you get the best, low carbon welds with those. I
also keep a glass brush in the chamber to remove any carbon build-up
as I’m working.

Honestly, some of the super thin jewelry you are describing is hard
for anyone to repair no matter how they do it. I think the repair
work you are doing is great training for you and will only make you
a better jeweler. You really can develop excellent torch (and laser)
control over time. Working under pressure can be a great teacher.

I don’t know of any good books for laser welding. I have seen a
couple of DVD’s, but didn’t find them very useful.

Hope that helps you a little bit.
Mark


#5

One thing you will notice about laser welding is that (similiar to
soldering) the closer the two parts you are joining are in mass, the
easier the operation. I hope that makes sense. What I mean is, when
you hold your laser wire butted up against the hollow form of the
chain, whichever of these two pieces is noticeably lighter will take
the majority of the ‘hit’ of the beam pulse. So, if you match the
pieces in thickness you can have success welding hollow chain. Roll
your 30 ga. wire down, or even used rolled-out solder, and then
adjust the energy down to the point where they weld instead of
evaporate. This can get you started towards building the piece up to
a useful weld.