gold modelling compound

Hi group,

I'm sure I read somewhere about a compound made from gold powder and
(perhaps) wax, that could be modelled by hand into shape and then
fired/heated to produce a solid (or alloy) gold item. I seem to recall it
was of eastern origin, perhaps Chinese?

Was I dreaming? :-) If not, I'd appreciate any info on this, or a website
URL is possible.

Many thanks,
Neil

On Sun, 13 Feb 2005 15:28:39 -0800, in ¸õ "puk" wrote:

Hi group,

I'm sure I read somewhere about a compound made from gold powder and
(perhaps) wax, that could be modelled by hand into shape and then
fired/heated to produce a solid (or alloy) gold item. I seem to recall it
was of eastern origin, perhaps Chinese?

Was I dreaming? :-) If not, I'd appreciate any info on this, or a website
URL is possible.

Many thanks,
Neil


Neil,

You're thinking of PMC, "Precious metal clay". It's available in both silver and gold
formulations, and works much like clay. Almost entirely powdered metal, with just a
little organic binder. The stuff originally was invented, if I recall, by Mitsubishi,
Japan. competing brands are available today. The compounds are modeled as claylike
materials, then fired in a kiln, or with a torch in some cases, to sinter the model into
a metal item.

Available from a number of sources. In the U.S., Rio Grande is one good source, but
there are others. Search for precious metal clay, or PMC.

Note that the stuff has it's limitations. The resulting object is considerably less
dense than traditionally cast or forged (etc) precious metals, since the sintered final
product has a substantial degree of porosity (It has to. To eliminate it would require
actual melting, which would of course destroy the form) So PMC pieces are not quite as
strong as things made from traditional metals. Also, the choice of alloys is limited.
Generally, one uses either fine silver or pure gold, though a couple high karat gold
alloy formulations are available. less choice, though, than with traditional metals.
One also has to contend with considerable shrinkage of the form while firing. Depending
on the brand and type of clay used, this can range from around ten percent, to as much
as 30 or 40 percent reduction in size. That makes creating detailed surfaces easier,
but makes making exactly fitted parts trickier.

Hope that helps.

Peter

On Sun, 13 Feb 2005 23:36:54 GMT, in rec.crafts.jewelry "Peter W.. Rowe,"
wrote:

Note that the stuff has it's limitations.

Oh, and I suppose I should mention that PMC is a LOT more costly, per ounce, than
traditional forms of the precious metals. With the silver, this isn't such a stopper,
given silver's pretty low basic market price. But with the gold types, it's a lot of
money.

Peter

"Peter W.. Rowe," wrote in message
...
On Sun, 13 Feb 2005 15:28:39 -0800, in ¸õ "puk"
wrote:

Hi group,

I'm sure I read somewhere about a compound made from gold powder and
(perhaps) wax, that could be modelled by hand into shape and then
fired/heated to produce a solid (or alloy) gold item. I seem to recall
it
was of eastern origin, perhaps Chinese?

Was I dreaming? :-) If not, I'd appreciate any info on this, or a
website
URL is possible.

Many thanks,
Neil


Neil,

You're thinking of PMC, "Precious metal clay". It's available in both
silver and gold
formulations, and works much like clay. Almost entirely powdered metal,
with just a
little organic binder. The stuff originally was invented, if I recall, by
Mitsubishi,
Japan. competing brands are available today. The compounds are modeled
as claylike
materials, then fired in a kiln, or with a torch in some cases, to sinter
the model into
a metal item.

Available from a number of sources. In the U.S., Rio Grande is one good
source, but
there are others. Search for precious metal clay, or PMC.

Note that the stuff has it's limitations. The resulting object is
considerably less
dense than traditionally cast or forged (etc) precious metals, since the
sintered final
product has a substantial degree of porosity (It has to. To eliminate it
would require
actual melting, which would of course destroy the form) So PMC pieces are
not quite as
strong as things made from traditional metals. Also, the choice of alloys
is limited.
Generally, one uses either fine silver or pure gold, though a couple high
karat gold
alloy formulations are available. less choice, though, than with
traditional metals.
One also has to contend with considerable shrinkage of the form while
firing. Depending
on the brand and type of clay used, this can range from around ten
percent, to as much
as 30 or 40 percent reduction in size. That makes creating detailed
surfaces easier,
but makes making exactly fitted parts trickier.

Hope that helps.

Peter

Peter,
Many thanks. Since reading your reply I've 'Googled' a bit and found quite
a bit of info on the stuff. I'll need to do some more reading though before
buying some (if I do) and trying it out. As you note, it's not cheap and
doesn't really compare to the real thing, so some thinking to do. I'm based
in the UK and haven't found a supplier here yet, but will keep hunting.

Many thanks,
Neil

Peter W.. Rowe, wrote:
On Sun, 13 Feb 2005 23:36:54 GMT, in rec.crafts.jewelry "Peter W.. Rowe,"
wrote:


Note that the stuff has it's limitations.


Oh, and I suppose I should mention that PMC is a LOT more costly, per ounce, than
traditional forms of the precious metals. With the silver, this isn't such a stopper,
given silver's pretty low basic market price. But with the gold types, it's a lot of
money.

Peter
How easy is the stuff to solder?

==RC

On Mon, 14 Feb 2005 07:38:30 -0800, in àõ Rick Cook
wrote:

How easy is the stuff to solder?

This depends some, upon which type of PMC formulation, as well as how it is fired. PMC,
as I noted, tends to produce a quite porous, less dense product. When you solder it, it
has a tendancy to soak up solder. That can be somewhat troublesome. But this does vary
from type to type, and even with this tendancy, it CAN be soldered. Just generally not
quite as easily as more solid metal.

Peter

Hi Neil,

There are two brands available, PMC and Art Clay. I'm a UK based Art
Clay distributor.

The clay is fantastic to work with, it allows a beginner to do things
which could have taken years to learn how to do using traditional metal
smithing techniques.

It can be soldered, just burnish the piece well after firing, to help
"compress" the surface a little where you are going to solder.

Things have changed over the years the product has been around.
Shrinkage has now come down to about 8-9% for the silver clay, and
about 15% for the gold.

If you want to learn more I have lots of info on my site,
www.silverclay.co.uk or send me an email.

Best regards
Petra Wennberg
www.silverclay.co.uk


puk wrote:
Hi group,

I'm sure I read somewhere about a compound made from gold powder and
(perhaps) wax, that could be modelled by hand into shape and then
fired/heated to produce a solid (or alloy) gold item. I seem to
recall it
was of eastern origin, perhaps Chinese?

Was I dreaming? :-) If not, I'd appreciate any info on this, or a
website
URL is possible.

Many thanks,
Neil