David Woof on sat 13 may 06
Paul, depending on their parent source and mineral chemistry many local
clays already contain "fluxing" materials. I always start with slakeing,
forming and fireing a sample straight from the earth at ^04, ^5 and ^10.
fire it on a dish or pad because it may melt and run all over where you
don't want it.
Field testing by odor, taste, observing other site geo formations and a shot
of vinegar will give you some expectation of what else it may contain.
It's a base starting point from which to test additions and evaluate
results.
Happy digging,
A side note: even a refractory highfire commercial body will display some
interesting and at times exciting character with additions of up to 30%
local clay wedged in. And some clays become a glaze with or without
additions of neph syn at higher temps.
David
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David Woof Studio
Clarkdale, Arizona
Ph. 928-821-3747 Fax. 866-881-3461
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peering over the edge, reverently taking an irreverent look at everything.
lee love on sun 14 may 06
Paul,
Can you use your local clay as they are, in the cool part of your
woodkiln? I have used bizen clay in the flue channel of my kiln with
good results. If your "cool spot" isn7t cool enough, might saggering
be a way to go? Beats having to do a special firing.
--
Lee In Mashiko, Japan
http://mashiko.org
http://seisokuro.blogspot.com/
Paul Herman on sun 14 may 06
Hello Charlie, David and Lee,
Thank you all for your thoughts. This is becoming an interesting
thread for me.
I'm just starting to test these clays, and have bisque fired one of
them. At ^06 it's still very porous, pink and looks like it needs
more heat. A lot more testing is in order. I would like to develop a
low temp maturing clay from this, in the ^06 to ^1 range.
One clay is from Nevada near Yerington, and I call it Jupiter Clay
because it's from the Jupiter Mine. The other is from my roadcut, in
a place where the runoff concentrates a clayey material, so I call it
Roadcut Clay. The roadcut is slightly altered rhyolite, and contains
a very small amount of clay, which I assume is a true primary clay. I
just love the fact that I get to name these materials. (hehe) Today I
plan to process the Roadcut clay and see what I can see.
Definition of a Mine, according to Mark Twain: A hole in the ground
with a liar standing next to it.
Good digging, in your own sweet hole in the ground.
Paul Herman
Great Basin Pottery
Doyle, California US
http://greatbasinpottery.com
On May 14, 2006, at 5:27 AM, lee love wrote:
> Paul,
>
> Can you use your local clay as they are, in the cool part of your
> woodkiln? I have used bizen clay in the flue channel of my kiln with
> good results. If your "cool spot" isn7t cool enough, might saggering
> be a way to go? Beats having to do a special firing.
>
> --
> Lee In Mashiko, Japan
> http://mashiko.org
> http://seisokuro.blogspot.com/
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