In industrial applications, engineers aware of that fact and make
sure not to exceed structural loads in these areas. In
goldsmithing it is quite another matter. Welding simply replaced
soldered joint without any compensation for deficiency in
conduction of the loads. What used to be soldered, now it is welded
and that results in jewellery of inferior quality. And that is my
point.
Leonid, you do of course make a valid observation that the
structureal differences over short distances are higher with a laser
weld than with a soldered joint. But your observations ignores the
fact that with a solder joint, the presence of solder itself, a
different metal compostion, not just stress level or crystal size,
also introduces differences in strength. And the solder joint on most
metals, is almost always annealed, which means more flexible and more
easily deformed and bent.
The use of a laser, like any tools, depends on more than the ability
to push the foot pedal. As with anything in metal, you must also
understand your material. And understanding the metal is included.
Within a short period of time after starting to use a laser, one
discovers things. You size a ring, for example, and hammer/planish
the joint to fully round out the ring. And discover that you’ve just
cracked the weld. Ok, so now you understand something more about the
nature of laser welds. You learn in some cases, to use settings on
the laser (pulse shapes, if your machine supports them) that allow
the cooling weld some time to at least partially stress relieve
itself. Those welds then don’t crack so easily. Or you learn to
design the shape of the weld to use the increased hardness, which
supplying strength where needed so the weld performs properly. Or you
can learn to use your torch after welding, to gently anneal or at
least stress relieve the metal, if your weld is in an area where the
heat can be tolerated. That operation is much lower heat than
soldering itself, and done correctly, results in a still not fully
annealed piece of metal that has uniform strength across the weld.
Again, this is part of the skill one gains with use of the tool, just
as proper use of a torch to solder requires one to learn things such
as how to properly fit a joint tightly, how to not use too much
solder, and which types of solder to use for a given situation.
Back to your illustration, though. The prong soldered on. Lets take
two prongs. Both platinum wire, in a basket style head. Put this head
together with solder, and the wire is dead soft annealed. Even with a
bit of working, after setting your stone, if you catch that prong on
something (and yes, with a well done setting that might not be all
that likely), and it will take less force to bend that wire back,
bending at the solder joint to the undergallery, and off the stone.
Now if instead, that head is made with laser welds, and you start
with wire that’s drawn down to be reasonably work hardened, then
after assembly, the wire, and the weld, remain thus work hardened.
Even if you gently stress relieve the metal (heat to just barely
glowing for a moment and quench, is enough), the wire will remain
substantially springier and stronger than the fully annealed version.
And the stone, after setting, will be just that little bit more
secure.
The assumption you’re making all through this argument is that the
laser is a “cheat” tool, used for it’s speed, allowing unskilled
workers to assemble some semblance of items that previously required
more skill. And there’s no doubt that some people are indeed using
lasers like that. But I’ll suggest that those same people, when they
previously were using a torch, were not exactly using it with full
mastery either. The tool, laser or torch, doesn’t dictate the
quality of the work. The user of the tool does.
And simply on the actual experimental observation level, I’ve been
using laser welders for close to ten years now. I’ve seen any number
of pieces that I’ve made over the years, and have been able to
observe how well they do, or don’t, hold up. While it’s not
universal, and some welds are problematic, on average, I can report
that the laser welds have generally been more durable and less
likely to fail or need repair over time. If this were not true, we’d
probably not use the laser so much. We don’t see sizing seams. Ever.
Even with platinum items sized right next to stones. No gold solder
to show up or be softer than the platinum so it polishes out or wears
differently. Repairs, like retipped prongs, last longer, and look
better. The harder welds simply don’t wear down as fast. I’ve seen
rings where someone has retipped a few prongs, and now I’m asked to
retip only the rest. When it goes out, they all now look like new,
but some are my laser welded tips, and others are the soldered on
tips. I’ll see the thing periodically when the customer brings it in
to clean and check, and invariably, the ones that were retipped with
solder, are more likely to show wear, or be bent or otherwise need
more work. I’m not guessing here, Leonid. This isn’t theory or
metalurgy being quoted. This is actual observation over a decade, of
actual jewelry as it’s performed in the hands of customers. I’ll
grant that well done soldering work is high quality. But on average,
there is a difference between the durability of the work we repair or
build with the laser (when appropriate), as opposed to work we or
others have done with a torch. Sometimes the difference isn’t great
or dramatic (though other times, especially if the solder work in
question is “average commercial quality” rather than expert
workmanship, the difference can be between wonderful and terrible
work)… But in general, the laser wins.
This isn’t guessing or theoretical, Leonid. It’s actual experience
and observation of the work we and others have done with the laser
and with traditional soldering methods. As I said before, the laser
isn’t universally better for everything. There are a substantial
number of jobs where the torch is better. But sometimes, when the
laser is the better choice, it’s dramatically better. And as with the
torch, if you use the laser carelessly or without skill and
understanding of what it’s doing, the results will often not be
acceptable. But when that’s the case, blame the user, not the tool.
Peter Rowe