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^10 clay body firing limit range

updated sat 24 jul 99

 

Maria Elaine Lanza on thu 22 jul 99

This may seem as a silly question... but, I'm going to ask anyway... am in
the process of using up clay that I've had for years in storage... found
some ^10 clay, probably Standard... since I only fire now between ^4 to ^6
in oxidation... will this ^10 body be ok fired between this range? I hate to
throw anything away... don't want to risk mixing this even in small amounts
with other ^6 clay... was thinking of throwing small forms or flower pots
just to use it up... what do you think... thanks in advance, Marie Elaine

douglas adams on fri 23 jul 99

At 03:22 PM 7/22/99 EDT, you wrote:
>----------------------------Original message----------------------------
>This may seem as a silly question... but, I'm going to ask anyway... am in
>the process of using up clay that I've had for years in storage... found
>some ^10 clay, probably Standard... since I only fire now between ^4 to ^6
>in oxidation... will this ^10 body be ok fired between this range? I hate to
>throw anything away... don't want to risk mixing this even in small amounts
>with other ^6 clay... was thinking of throwing small forms or flower pots
>just to use it up... what do you think... thanks in advance, Marie Elaine
>



Yes.!

NakedClay@aol.com on fri 23 jul 99

Hi Marie!

It's fine to underfire a cone 10 clay to cone 6. The caveats to be aware of:

--The color of the clay may be lighter at cone 6 than cone 10.
--The clay is not fully matured at cone 6; hence, it will absorb moisture,
and may leak if constantly in contact with water.

I've been firing cone 10 clay to cone 6 for many years, without problems. I'm
not a "functional ware" potter; however. I make ceramic masks and other
decorative items.
The problens I've had are finding cone 6 glazes that "fit" the clay--a common
problem most cone 6 ceramicists have. The best solution is to experiment--go
beyond the fear of the unknown--make a test tile, using a new glaze with a
familiar clay body.

As to whether mixing cone 10 clay with a mid-fire clay is ok, I suggest you
blend a little of both clays together, make a test tile from the blended
clays, then fire the tile to cone 6. Chances are good that you'll have a clay
that will hold up to the mid-fire range.

One more thing to consider: Cone 6 temperatures are about 200 degrees F less
than cone 10--the small difference in temperature is what makes the
difference in qualities between firing in mid-fire range, and firing
high-fire.

I hope this is helpful!

Milton NakedClay@AOL.COM

Eagerly counting down the days until my three-week camping trip to New Mexico
begins!