This is where i get into trouble. I haven't yet figured a
foolproof way to hold down the two pieces on a charcoal block so
that I end up with a perfect fit around the stone
Hi Dave, I'm sure you're going to get some great tips, so I'm
going to introduce you to a process that is used by fabricators
for complex assembly jobs. It may be extreme overkill for your
needs, but you will use it from this day on. If you already know
this process, okay, maybe some of the other jewelers here can
benefit from it.
Wax and plaster assembly technique.
This is an extremely brief explanation. I'll be glad to follow
up for questions.
You will need a few items;
some quick setting dental plaster (any dental supply has it, a
dental lab might give you a few ounces to get you by, it's
cheap) regular investment works, but sets slowly.
Kerr #1 sheet utility wax. or any other very soft wax that parts
can be pressed into and stay put.
A mixing bowl, paper cups are ideal.
A mixing spatula, popsicle stick work great a small amount of
You begin by pressing the pieces the pieces you wish to solder
into the wax in exactly the position you wish them to be in once
soldered. The depth you insert the parts into the wax depends on
how much plaster you want holding the pieces together once the
wax is removed, I typically push them in about halfway. You will
probably want to coat the seams with some wax to keep the
plaster out. Once all the pieces are positioned, you mix up a
small amount of very thick slurry and quickly build it up over
the metal/wax unit. I then turn the wax over and place it on a
flat sheet of wax paper (or anything flat the plaster won't
stick to) and let it dry for a few minutes.
Pulling the wax off can be tricky, you might try heating the
plaster enough to drip the wax off, off just enough to pull most
of the wax off. The remaining wax will burn away when heated
with the torch. Once the wax is removed, you may need to scrape
some of the plaster to allow the torch flame access to the
parts. You must make sure all the plaster is gone from the
seams. What you have now is any number of pieces presented for
If you arranged them carefully, they will be fairly secure and
heat sinked as well, and you can do all your soldering at once.
This technique is very useful for fusing techniques as well.
Because you are working on the underside of the item, and
because the pieces are effectively heat sinked, it is possible
to actually carefully melt the items together, in certain
circumstances. I have used this technique with complicated
platinum fabrications, and otherwise seemingly impossible
It's a standard jewelry fabrication method, and should be in
every bench jewelers collection of techniques.
I'll be happy to field any questions that result from this
(poorly presented) method. There is much more to it, and I will
gladly get into more advanced techniques in answer to queries.