Ginny Webb on mon 8 sep 03
Some years ago, a friend gave me about 50 pounds of clay and said "I think this is
low fire clay." It has sat in a trash can in two layers of plastic for several years but
remained moist. Today I decided to wedge and throw this clay with an unknown
firing range. I can bisque a test pot or two at C/04 and see if the pot can be
scratched with a nail. This means that it is low fire clay as C/6 clay is much harder
after it is bisqued. I know that you can put a pot in a C/6 saucer and fire it. If it melts it
must be a low fire clay body. Are there any other tests when you are not sure
whether a clay is low or midfire? Needless to say, I will need to match the glaze to
the clay body. Your help in solving my firing temp mystery for this will be welcomed.
Marcia Selsor on tue 9 sep 03
You can make some little coils and support them over a couple of ridges.
If they sag alot in a higher temp. they are low fire. If they turn to a
glaze, you have a new material.
Marcia Selsor
Ginny Webb wrote:
> Some years ago, a friend gave me about 50 pounds of clay and said "I think this is
> low fire clay." It has sat in a trash can in two layers of plastic for several years but
> remained moist. Today I decided to wedge and throw this clay with an unknown
> firing range. I can bisque a test pot or two at C/04 and see if the pot can be
> scratched with a nail. This means that it is low fire clay as C/6 clay is much harder
> after it is bisqued. I know that you can put a pot in a C/6 saucer and fire it. If it melts it
> must be a low fire clay body. Are there any other tests when you are not sure
> whether a clay is low or midfire? Needless to say, I will need to match the glaze to
> the clay body. Your help in solving my firing temp mystery for this will be welcomed.
>
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--
Tuscany 2004
http://home.bresnan.net/~m.selsor/Tuscany2004.html
Snail Scott on tue 9 sep 03
At 06:45 PM 9/8/03 -0400, you wrote:
>I can bisque a test pot or two at C/04 and see if the pot can be
>scratched with a nail. This means that it is low fire clay as C/6 clay is
much harder
>after it is bisqued.
I find that the opposite is generally true -
that the higher-fire the clay, the softer
it will be at the same bisque temperature.
-Snail
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