Alisa and Claus Clausen on thu 21 sep 00
Cindy has some good points, and I have some of the same experiences with =
a super body that ranged from cone 04 to 8.
NOT:
The person who is no. one responsible for the community studio where I =
volunteer described one of the clay bodies=20
as "German White Clay", which could both be fired as earthernware or as =
stoneware.=20
I fired it as earthernware, with slips and transparent glazes and spend =
2 months trying to figure out why the glazes=20
were shattering off of the lips immeadiatly, and ultimately crazing over =
the entire pot a day or so later.
I changed every variable I could think of, pestered clayart with more =
and finally changed my claybody.
The moral to this months of PITB clay, is that I took someone's word for =
it, and even though I tested it and tested it,
I still believed that it had this fantastic, flexible firing range, =
because "she said so." Who am I to doubt the person in charge who has =
used this clay for "20 years" with no problems"?
Months and many clay type tries later, I recently read up on "German =
White Clay". It is listed as an earthernware, however the versions with =
either 0.2mm or 0.5mm grogg/25% CAN be fired up to 1220c, because of the =
grog. The groggless version has a max. firing temp. 1100c.
So, I am thinking, why could I not get it to fire as earthernware with =
an earthernware glaze that fit?
IF the clay at the studio had been "German White Body" I may have had =
some success firing it cone 05.
HOWever, upon a recent check in the studio clay bin, I saw a plastic bag =
from the white clay. It is not even that clay!!!
This person has been ordering a completely different white body, =
albeight from Germany, that is called KM and it has
the same grogg/25% but has a min/max. firing temp. of 1220c-1280c.
I will spare all of you my reaction. But I did try to rectify the =
problem by showing the studio in charge person the error,
and you know what, she just cannot understand how the clay factory made =
that mistake. She still insists that clay we
have in the bin is German White and the bags are wrong. I am =
mystifyied. I better understand how sometimes working in a communal =
studio can drive one batty. But not so much that I will instruct my =
students to use it for stoneware, because, it is stoneware.
The clay I have now is a cone 6-8 range and is very nice and behaves and =
I am happy.
Just a side note. My supplier fired every clay type they offer to cone =
6. They all stood up except for the common red clay.
This does not say that there will be a good glaze fit and all that, but =
it was interesting that none of the low fire bodies (1020-1040c)
melted into puddles at 1220c.
Life is good.
Best regards,
Alisa in Denmark
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