Clay

Hello Everyone, I am also making molds of wood and other substances.
I got a free sample of Quick-Sil from Castaldo and this works just
fine - no problem whatsoever (it didn’t cure in 15 minutes, but this
is hardly a problem). However, I found a technique that I would like
to try out in Codina (p. 84). It’s about making impressions in clay,
then add a little lip and pour wax into the mold. I went to an art
shop today (Michaels). They have clay, but no one was able to tell
me whether this clay could withstand the hot wax poured onto it.
Contenti sells a clay too, but it is of the plasticene-type (I think
Gesswein has the same). Could someone tell me where I can buy the
proper sort of clay to do this? Thank you and best regards, Will

I use Plumbers putty used on Stainless Steel sinks it never gets
hard and will handle the heat if it gets stiff just roll it in your
hand like clay and will last for years you can use it over and over.

Art

Any good potters clay will work. Just make sure that it feels smooth
and has no grit in it. You can cast wax into plasticine and polymer
clay as well - make sure the wax is just melted and not boiling hot

Tony Konrath
Key West Florida 33040

Will-- Any ceramic clay should work just fine, if you can pour while
it is still wet. If it is dry, a layer if clay might become
impregnated with wax, so experiment. Spraying it with Pam or the
like might solve this. Spraying bone dry clay with water would cause
the surface to disintegrate, as the dry clay readily dissolves and
swells, breaking the wet, swollen clay off from the dry, shrunken
clay behind it (a process called “slaking”). To buy it, trey a hobby
shop or a “ceramics” shop. Ceramic supply houses will often send a
5lb sample for free-- they sell 25lb bags, which you don’t need, I
think. A local nursery school or art center might let you have a
chunk. I like to use polymer clay, but have used it to mold PMC. Wax
might not come out easily if it is fired. Wet might work. I’ve been
experimenting with my free sample of Quick-Sil as well, and really
like it. I rigged a couple of “mold frames” out of available
materials, weighted with steel blocks. I even made a two-part mold
by hardening one part, dusting with cornstarch, and adding another
layer. It doesn’t seem to stick to anything except itself-- great
stuff! --Noel

Hello Will,

    shop today (Michaels). They have clay, but no one was able to
tell me whether this clay could withstand the hot wax poured onto
it. 
Have you thought of ceramic clay?  It certainly won't deform when

exposed to hot wax. As long as it is kept in a sealed container, it
remains pliable indefinitely. If it becomes too stiff, one simply
kneads in some water - messy, but effective. Just a thought. Judy in
Kansas

Judy M. Willingham, R.S.
Biological and Agricultural Engineering
237 Seaton Hall
Kansas State University
Manhattan KS 66506
(785) 532-2936

I think this technique requires a water-based potter’s clay. A
plasticene-type (oil and wax based) clay would dissolve into the
wax, but the water-based clay will repel it, creating a better
surface. You’ll only get one good impression for each clay mold, and
be prepared to clean off the wax with toothbrushes. Sculptor’s wax
(Victory Brown) will work better than most jewelry waxes for this
sort of thing. You can get potter’s clay at any ceramic supply
store. If there aren’t any of these in your area, you can go online,
although shipping will be high on heavy items like clay. While I
don’t know specifically where you’d find clay in your country (dig
for it?) here’s a link that might produce some leads:
http://www.ceramica.be/.

Andrew Werby

I use Plumbers putty used on Stainless Steel sinks it never gets
hard and will handle the heat if it gets stiff just roll it in
your hand like clay and will last for years you can use it over and
over. 

I am sorry. I don’t think Plumbers putty works as it sticks far too
much to the wax. I tried to clean the wax with a toothbrush, but it
was impossible to do so without blurring details. I will try again
with ceramic clay. But thank you Art, and also Judy, Noel and Andrew.
Best regards, Will

Hi Will, I haven’t tried this, but I’d be tempted to try a polymer
clay (such as Fimo, Premo or Sculpy) to make the mold. This clay has
to be conditioned by kneading it or running it through a pasta
machine (once used with polymer clay the pasta machine should NOT be
used for food again). This clay when conditioned is quite elastic and
could be used to press something into and is capable of very fine
detail. It is slightly flexible when cured (baked) and would be able
to be reused many times (some of the poly clays are more flexible
than others- read the labels). If the wax is sticking- try a silicone
mold release spray. Be very careful when melting wax, as it is quite
flamable. HTH, Kate Wolf in spectacular Portland, Maine- hosting
workshops by the bay. http://www.katewolfdesigns.com