HI All,
I need some info on working with platinum. I do more work with Karat
gold pieces, Have had a few platinum channel set rings to size
lately. Everything was going fine till today. Today, the ring had a
few .11 diamonds and 3 of them clouded up to a milky white. This has
not happened before. If anyone can help, it would be greatly
appreciated.
Thanks in advance Harold
Harold: It sounds like you frosted the diamonds. If you were fusing
the plat., it melts at over 3000 degrees. That is enough to burn the
surface of the diamond. Not a good thing. You will need to replace
them. If in the future, you size platinum, either shield the
diamonds, use a laser welder or use a good platinum solder. Not the
cheap stuff. I got some real nice plat solder that actually has
platinum in it that doesn’t leave a line like the others. I use a
laser now, so I have none of the above problems. The above knowledge
does come from experience, though…
JB
Today, the ring had a few .11 diamonds and 3 of them clouded up to a milky white.
You got the diamonds too hot, or perhaps they were not properly
cleaned first. Diamonds, when very clean, and coated with boric acid
or a good flux, can take fairly high temps as in normal gold
soldering. But even coated and cleaned, they don’t withstand the
temps needed for platinum soldering or welding. Platinum is not a
good conductor of heat, so working quickly, perhaps with some
tweezers strategically placed as heat sinks, you can solder platinum
somewhat close to set diamond (I usually figure no closer than about
3mm), without the heat traveling far enough to damage the diamonds.
But if the diamond is glowing much at all, not to mention the bright
incandescent temp of soldering or welding platinum, they are gonna
burn, which leaves them white and frosty/milky looking. If large
enough, they can be repolished, with only slight loss in weight, but
the cost of repolishing usually exceeds the value of a melee
diamond. . Now, if you want a good argument in favor of laser
welders, this kind of work is it. Though a laser, at higher powers
especially, is still quite capable of causing major damage to a
diamond if you actually hit the diamond, when used carefully you can
weld platinum that’s literally in contact with the diamond, without
much risk to the stone. One of the rings we manufacture is a narrow
channel set eternity band with fifty .01 diamonds set girdle to
girdle all the way around. with the laser, I can cut that puppy to
size it, and weld it back together seamlessly. occasionally I’ll
kill one of those melee when doing this, if I aim wrong and actually
blast the diamond, but most of the time there’s no problem. I sure
wouldn’t want to try this with a torch…
Peter
Harold,
You my friend are trying to deal with something that any jeweler who
works reguraly with platnium experiences. You smoked the diamonds!
Take those diamond out and let someone with a laser welder fill in
your seats so you can save the ring. If you don’t have access to a
laser then contact me and I’ll help you out.
Scott Isaacs
Berry’s Jewelry Co.
Nashville,TN
Laser and Cad/cam services
the diamonds clouded up because they got too hot. They have lost
their polish. This happens at about 1690 F. They have to be removed
and sent to a diamond cutter for polishing. where I work we
generally don’t torch weld platinum closer than 1/4 a the shank away
from diamonds, i also use clamps to act as heat sinks between the
seam and the diamonds.
Any welding that is closer than that should be lasered, or soldered
with a gold solder (not my favorite solution but sometimes
necessary. Those diamonds aren’t a dead loss, you may have to replace
them with new, but if you have any chipped stones as well, you can
wait till you have a bundle and send them all out for
cutting/polishing at once. It’s
usually cheaper this way. Hope this helps
Gail
...if you have any chipped stones as well, you can wait till you have a bundle and send them all out for cutting/polishing at once.
Recommendations on where? Minimum size diamond worth recutting
(assuming high quality)?
Thanks!
Noel
Thank you everyone who replied to my question. I have come a long way
with this problem, other than having sone Diamonds we can’t use
again. but live and learn huh? I’m using more heat sinks and being way
more careful now
Thanks again
Harold