Paul on mon 24 nov 03
Hello,
i recently switched from a commercial stoneware to a body i mix myself which
is generally working well for me. The only problem is that it is a little
harder to throw with, especially for thinner-walled pots, which i think is
because it is a more coarse body. It tends to snag on my fingers a lot while
pulling. Could the relative difficulty in throwing have to due with the
fairly high fire clay content? My next test is to cut down the fire clay and
up the ball clay and goldart slightly. If anyone has any advice i would be
thankful to hear it. thanks.
here is the recipe:
goldart 30
hawthorne fireclay 35
om-4 ball clay 20
silica 10
g-200 8
grog 4
Paul B
Falmouth, KY
Michael Wendt on mon 24 nov 03
Paul,
I find the best way to increase the plasticity if you can't fluid slip the
clay is to take the ball clay first, mix it with the amount of water you
intend to use long enough before hand to allow it to fully disperse. If it
is still very thin, add the next most plastic clay until you get a very
thick slip and age that. Blend the rest of the body dry first in the mixer
and then add the slurry uniformly on the side the mixing arms move toward to
keep the mix lubed. When you have all the slurry mixed in, you will have a
more plastic mix.
Some people add bentonite to a body this way, but be very careful to add as
little of it as you can get away with. I never use it to avoid the problems.
Paul wrote:
here is the recipe:
goldart 30
hawthorne fireclay 35
om-4 ball clay 20
silica 10
g-200 8
grog 4
Paul B
Falmouth, KY
Michael Wendt
Wendt Pottery
2729 Clearwater Ave
Lewiston, ID 83501
wendtpot@lewiston.com
www.wendtpottery.com
David Hendley on tue 25 nov 03
I think you are on the right track for making your claybody
less coarse. I would suggest
Goldart 35
fireclay 25
ball clay 25
as a good next experiment. But, remember that even a small
batch has to be aged for a while to make it a valid test.
Another big factor could be the grog. If you are using 28 mesh
grog, varying the clay proportions won't change things that
much because of the large size of the grog.
David Hendley
david@farmpots.com
http://www.farmpots.com
----- Original Message -----
> i recently switched from a commercial stoneware to a body i mix myself
which
> is generally working well for me. The only problem is that it is a little
> harder to throw with, especially for thinner-walled pots, which i think is
> because it is a more coarse body. It tends to snag on my fingers a lot
while
> pulling. Could the relative difficulty in throwing have to due with the
> fairly high fire clay content? My next test is to cut down the fire clay
and
> up the ball clay and goldart slightly. If anyone has any advice i would be
> thankful to hear it. thanks.
> here is the recipe:
> goldart 30
> hawthorne fireclay 35
> om-4 ball clay 20
> silica 10
> g-200 8
> grog 4
>
Rudy Tucker on wed 26 nov 03
I use a body that is similar, same clays anyway. Shown below in percentages.
Yours on the left/ mine on the right. I fire cone 10-11 wood and salt. I'm
well pleased with both it's plasticity and green strength.
28 goldart 62.5
32.7 hawthorne 15.6
20 OM 4 15.6
7.5 spar 1.6
3.7 grog 4.7(silica sand)
9.3 silica 0
Two biggest differences are that you have 16.8% fine particle material to my
1.6%. And that you use twice the fireclay although I don't think is your
problem. I'd cut back on the spar and silica unless you really need the spar
to
flux the body. You didn't say how hot you fire. Also i would think that if
you cut back on the fireclay you could use less flux.
Rudy
in the Shenandoah Valley of Virginia
----- Original Message -----
From: "Paul"
To:
Sent: Monday, November 24, 2003 12:04 PM
Subject: help needed with stoneware formula
> Hello,
> i recently switched from a commercial stoneware to a body i mix myself
which
> is generally working well for me. The only problem is that it is a little
> harder to throw with, especially for thinner-walled pots, which i think is
> because it is a more coarse body. It tends to snag on my fingers a lot
while
> pulling. Could the relative difficulty in throwing have to due with the
> fairly high fire clay content? My next test is to cut down the fire clay
and
> up the ball clay and goldart slightly. If anyone has any advice i would be
> thankful to hear it. thanks.
> here is the recipe:
> goldart 30
> hawthorne fireclay 35
> om-4 ball clay 20
> silica 10
> g-200 8
> grog 4
>
> Paul B
> Falmouth, KY
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>
| |
|
