Johnnie J. on fri 2 sep 05
I have been asked by a local direct farm market to participate in their Farm Heritage Day this October. The purpose is to "connect" people with what was done and how it was done way back when so to speak.
They have found several small pieces of pottery made by the Native Americans from 100's of years ago that show texture on them made from corn cobs, pine cones, shells and the like. They also have an area of local clay and have brought me some to see if it could be used as part of a demonstration of that same period. They clay is extremely short and very sandy. My questions are: 1.) could this be the same clay that was used by the Native Americans? 2.) what if anything can I add to the local clay to make it more plastic? 3.) should I screen it to remove the excess sand content? 4.) how do I determine what temperature/cone to fire to? 5.) other than oxide washes, what could have been used for glazing or surface coloring on these pots by the Native Americans?
My goal is to have people (especially children) make a small pinch or coil pot on the farm sight and then have them pick up their pieces here at my studio after I have fired them.
If there is interest in this to the list, please respond on list. I'm sure some of you Clayarters out there will know how to go about making this idea a do-able event and look forward to your replies, on or off list!
Thanks in advance for your help,
Johnnie J. (John Johnson)
Mud Bucket Pottery
mudbucketpottery@yahoo.com
www.mudbucketpottery.com
(843)399-8702
(843)340-1674 cell (when it works)
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Fredrick Paget on fri 2 sep 05
> They clay is extremely short and very sandy. My questions are: 1.)
>could this be the same clay that was used by the Native Americans?
>2.) what if anything can I add to the local clay to make it more
>plastic? 3.) should I screen it to remove the excess sand content?
>4.) how do I determine what temperature/cone to fire to? 5.) other
>than oxide washes, what could have been used for glazing or surface
>coloring on these pots by the Native Americans?
>
>
>Johnnie J. (John Johnson)
>Mud Bucket Pottery
Every potter should know how to prepare and use local clays. Way
things are going that may be all that we can get or afford. Local
clay and wood fire - way to go.
OK enough of that.
It is easy and simple - Levigate. Look it up.
For those too busy to look it up it means soak the bone dry clay in
water until it slakes down, then add a considerable excess of water,
stir it up, and then let it settle for a few minutes and pour off the
clay in the water into another tank or bucket, leaving the sand and
rocks behind. If there are roots and stuff floating strain it. Let
the clay water settle for a day or two and take off as much top water
as you can and then dry out the slip in some manner such as plaster
bats with a depression. or canvas bags hung up or on a concrete
surface in the hot sun etc
.
Old time potters used to do this in a couple or three of tanks and
flat shallow pond areas with hard bottom. I've seen it done in Agost,
Spain and several places in China to this day.
The resulting clay may be too sticky and shrink too much so that it
is prone to cracking. To remedy this "temper" is added. This can be
fine sand or grog. You have to experiment to find out how much to put
in. Aging improves plasticity. So does an addition of ball clay but
that may not be authentic in this case.
An easy way to find the firing temperature is to make a cone of the
Bar type from the clay and put it in the kiln sitter of a small
electric kiln. Fire it up and when the sitter drops note the
temperature on the controller or thermocouple or lacking those you
could make up a cone pack with a series of Orton cones. When the
kiln cools off the last cone down will show your firing temperature.
--
From Fred Paget,
Marin County, CA, USA
fredrick@well.com
Charter Member Potters Council
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