Working with Bronze metal clay

Hello friends,

I have worked in Precious Silver Metal Clay., I am interested in
trying a new product. I see that Bronze and Copper Metal clay is
available thru Rio Grande. The instructions say you need to put the
Bronze metal clay in charcoal and a steel container in the kiln
while burning out the binder…The container they sell is 7 inches… I
have a kiln with a 4 inch opening. Does the size of the charcoal
container matter?. or is it designed to fit in their kiln specificaly
Any answers welcomed…

Barbara Kennedy,

Does the size of the charcoal container matter?. or is it designed
to fit in their kiln specificaly 

The container needs to fit in your kiln. As you have a small kiln,
you need a smaller container. Go to a hardware or kitchen store and
purchase a small stainless steel bowl or measuring cup that will fit
in your kiln (take a measuring tape or ruler with you and your kiln
dimensions). At a hardware store, you should be able to purchase a
flat sheet of stainless steel that can be cut to a size that will
cover your bowl or measuring cup.

Activated carbon can be purchased from a metal clay supplier or at a
pet store–it is the stuff used in fish tanks. However, if purchasing
from a pet store, be aware that you should purchase coconut based
carbon that has NOT been acid washed. The coal based carbon is ok for
bronze clay, but not recommended for copper clay because the quality
is not as consistent as the coconut based carbon.

Also, check out the alternate source for base metal clays and
instructions available from Hadar Jacobson at

Mary Ellin D’Agostino, PhD

You can also use a small stainless casting flask–you can get them
in 2" or 3" height and diameter.

Although the size of the container doesn’t matter, having a container
filled with activated charcoal in which you will fire your piece is
essential. A stainless steel container that will have at least 1 inch
below and above your piece and at least 1/2" of carbon between your
piece and the walls of the container is the minimum requirement for
Bronz clay or Copper clay. Feel free to Email me directly if you have
questions, I’ve been working with the Bronz clay for more than a year
and the Copper clay for the past two months.

Sandra Graves, Isis Rising

The sink that Rio Grand sells is simply a restaurant supply item. It
was not specifically designed for use in their kilns. Restaurant
supply stores also sell a shorter sink. I bought mine at Smart and
Final, but sells a wide variety of BronzClay and
CopprClay supplies.


Stainless steel containers in various sizes and shapes can be found
at good restaurant supply stores.

Mike DeBurgh, GJG
Henderson, NV

Stainless steel containers in various sizes and shapes can be
found at good restaurant supply stores.

I got mine used (cheap) on eBay, searching “steam table pans”.


Hi Fellow Metal Clay Artists,

I just recieved my Bronze Metal Clay in a box yesterday. It was 106
degrees here (unusual for Portland,Or.) It was out for 4 hrs, on my
porch…It is still in the package. It is semi- hard…to the
touch…Is that normal or did The Hot weather cook it in the foil
package? any ideas?

Sincerly, Barb., Kennedy

Bronze and copper metal clay are a standard powdered sintered metal
base with a lithium based soap to make the powder free flowing. This
is a normal material used to make sintered metal parts This is made
in to a bit plastic clay so you can work with it by adding a bit of
water. This is why you don’t see it as free flowing. The lithium soap
has a very unusual property that is counter intuitive. Normally you
would expect a material to be more fluid or softer hot than cold, but
this works backward!! it is more fluid or softer cold! This is due to
the Lithium and it is really an unusual property. I was puzzled by
this for quite a bit too. Cool it down and it will soften up. Don’t
freeze it or it will then be hard as the water turns to ice.


It takes far more heat than sitting on your porch in hot weather to
fire bronze clay. You may need to add a bit more water when you work
with it in hot weather, but the clay is just fine. I prefer to work
with my clay having been refrigerated, but it works fine at room
temp also.

Sandra Graves, Isis Rising


Metal clay folks have learned that it’s easier to work with if it is
stored in the refrigerator. I’ve been told to wrap it in plastic wrap
and put it in an air tight plastic bag, and then store it in the

Also, I understand that we don’t want to put the pieces in our
dehydrators and that it’s better to let them dry in the fridge as
well before firing. LOL, who knew? has a number of videos and there are several
on bronze clay as well. Mardel does the videos and they are quite
easy to follow.

Have fun!
Judy Bennett

I have info. and links to more on my blog. And check out MShindel’s
new squidoo lens on the subject: