David & Diane Chen on thu 24 jun 99
Okay, I am beginning to realize that my productivity would increase if I =
could
have some consistency in my product along with diversifying a bit. Since I =
can
only work with handbuilt items, I thought slump molds might fill the bill. =
Now,
when I learned about pottery at the local ceramic place, they had several
plastic yard sale type bowls that you could line with newspaper then drape =
the
slab over it, and trim accordingly. Once it was a little harder you had to =
slip
the bowl out. I see ads for slump molds and am wondering if I made a slump =
mold
out of (plaster, latex, rubber? WHAT SHOULD BE USED FOR SIMPLE FORMS i.e.
bowls), do I still need to do the newspaper bit and slip the item out before=
it
is leatherhard?
Thanks
Diane
Massachusetts
Dr.Tom Roess on fri 25 jun 99
------------------
Diane, You want Pottery plaster to make your molds. You won't need the
newspaper as clay doesn't stick to plaster. A slump molded piece can be
left to dry in the mold and will pull away from the mold as it dries.. A
hump molded piece will crack as it shrinks if left on the mold. There is
lots of information on mold making in the Clayart archives - probably more
than you care to know, but a great resource.
Lou in Snowmass
k.smead on fri 25 jun 99
diane..
you need to buy plaster (U.s.Gypsoum Pottery number1 or blue diamond green
tag) that is as hard
when they set. I usually buy mine from a company locally that sells
building supplies. I have used the plaster of paris carried by Home Depot...
but it is not as hard and your molds will chip more readily and that is a
problem in your studio...
Also... if you buy the harder plaster..it comes in large bags and you willl
need to seal it well because it
loses its strength and hardness if left for long period.
I have purchased a number of slump and hump molds... but i find things at
flea markets and in dumpsters that work real well... look for bowls or
containers that are totally round...no indention for
the bottoms... Woks work well and i recently found an absolutely huge one at
a used restaurant equipment store...(find those joints..they are a blast!!).
With the huge wok i can pour small mold as well as large ones...and it fits
over the burners on my raku kiln for tempora shrimp eat-outs..
I found a fiberglass pool filter my neighbor was throwing out and cut it in
half. Now, i spray it down with
pam or WD40 and use it as a slump or for coil building sinks and fountains..
Making plaster molds is a messy job ....but its fun to have alot of options
(sizes and shapes) for
various works..
You can also use any container almost...so experiment. If you are making a
plaster mold from it just
dont forget to seal any cracks with clay and spray it generously with WD40
or Pam..
email me if you need any assistance...have fun...
katie
klay@pcola.gulf.net
----- Original Message -----
From: David & Diane Chen
To:
Sent: Thursday, June 24, 1999 9:39 AM
Subject: question about slump molds
> ----------------------------Original message----------------------------
> Okay, I am beginning to realize that my productivity would increase if I
could
> have some consistency in my product along with diversifying a bit. Since
I can
> only work with handbuilt items, I thought slump molds might fill the bill.
Now,
> when I learned about pottery at the local ceramic place, they had several
> plastic yard sale type bowls that you could line with newspaper then drape
the
> slab over it, and trim accordingly. Once it was a little harder you had
to slip
> the bowl out. I see ads for slump molds and am wondering if I made a
slump mold
> out of (plaster, latex, rubber? WHAT SHOULD BE USED FOR SIMPLE FORMS i.e.
> bowls), do I still need to do the newspaper bit and slip the item out
before it
> is leatherhard?
>
> Thanks
> Diane
> Massachusetts
William Hewlett on fri 25 jun 99
------------------
Diane,
Inexpensive plastic containers, bowls, etc., of various sizes and shapes
can be bought at Walmart. I have made hump molds from them out of plaster.
Put vaseline on the inside of the plastic, and mix up plaster and pour in.
Once the plaster is hard, it will slip out of the plastic container. You
don't need to put newspaper over the mold before the clay, as clay won't
stick to plaster. I also made various shaped drape molds on the wheel and
bisque fired them. Clay can be put in the bisque molds, without newspaper
because it won't stick to that either.
Joyce A
| |
|
