Back to Ganoksin | FAQ | Contact

Hard solder to a diamond

How close could I hard solder to a diamond? My daughter has just
presented me with her grandmother’s engagement ring on which the
shoulder of the shank has come adrift from the head. The ring is 9
carat gold and the head is gold on the bottom and platinum around the
stones which are three small diamonds in almost closed settings. The
shoulder of the shank was originally soldered along almost the whole
length of the three stones onto the gold part of the head. I don’t
have access to a laser and don’t know of any jewellers around here
who do have one. I do have oxy-propane and a torch which will give a
flame down to about 2mm in length and I am wondering if I dare try to
use this with the tops of the diamonds stuck into / against a potato
or wet cotton wool… Any thoughts?

Best Wishes,

Ian W. Wright
Sheffield UK

Continue from:


One of the beautiful things about repairing Diamond Jewelry is that
the gems do not need to be removed or protected with a heat sink type
material. You can solder a tip on a prong that is set with a Diamond
with no ill effect.

If you are soldering close to or on the Diamond itself the only
cautions you need to follow is to check the Diamond for an major
fractures or inclusions as well as to make sure there are no Fracture
fillers involved. Make sure the Diamond is perfectly clean or any
dirt that is on it could potentially burn on to the surface and can
only be removed by boiling in acid or repolishing the stone.

One last caution is to let the Diamond cool slowly and do not quench

Good luck
Greg DeMark


Provided that the diamond isn’t too flawed, coating it with boracic
acid/alcohol mix will protect the stone unless you are REALLY
determined to do damage. But even after years of repairs an antique
piece ALWAYS sends up warning flags! The metal identification
problematical, alloys might not behave in the expected ways typical
of recent alloys, unusual fabrication/past repairs, are the diamonds
(?) rose cuts with foil underneath, etc etc… Repair or replacement
in case of the unexpected is difficult; the only time I ever quoted a
repair at X.XX dollars per hour for as many hours it took was for
fixing another jewellers simple heir loom repair.

If you are not confident with your experience, discretion might be
the better part of valour. Despite the above cautions it really
doesn’t sound like a difficult job but maybe it isn’t ideal as a
learning exercise. Any local jewellers whose skills you trust?


Demand Designs
Analog/Digital Modelling & Goldsmithing

Hello Ian;

I don’t know your skill level with repairs of this sort, so I’ll err
on the safe side . . . forgive me if it seems patronizing in tone. You
shouldn’t have any problems with the diamonds as long as you abide
by four conditions.

  1. make sure the diamonds a clean and covered with a boric
    acid/alcohol mixture.

  2. never heat them to a visible red color. It won’t hurt them to
    momentarily get red hot, but if they do, the longer they stay that
    way, the greater the risk of burning the surface of the diamond.

  3. allow them to come up to temperature somewhat gradually, and let
    them air cool, never quench them.

  4. if the diamonds are heavily included or fractured, the risk is
    considerably greater that they’ll be damaged by heating. This,
    unfortunately, is a judgement call. Let’s just say, if it’s easy to
    see inclusions with the naked eye, it’s risky. A few small black
    flecks shouldn’t be a problem, a white feather might be cause for

Now, your greater problem is previous solder seams. It might be
advisable to use a relatively low temperature hard solder, such as
easy or extra easy. And while you’re at it, just to prevent problems
of old solder flowing into areas that you’d rather it didn’t, you
might use yellow orchre or water based white out (typewriter
correction fluid), or even rouge dissolved in water, to paint the old
solder seams before you do any work. Take care, if you are applying
liquid flux while the article is warmed, not to splash it on the
diamonds and thereby shock them. Best of luck.

David L. Huffman


Thanks to everyone who has offered advice and help on this… once
again Orchid has come up trumps!

Best Wishes,

Ian W. Wright
Sheffield UK