Michele Hoskin on fri 5 mar 99
Hi everyone!
I have been throwing large plates recently with very wide rims.
Occasionally these rims need propping during the drying stage but often
they rise and need to be pressed back down to horizontal.
In the bisque kiln, I have stacked them in twos rim to rim. The rims seem
to droop slightly after this and I wonder if it is due to the stacking?!
I have just begun to use cones with my kilnmaster kiln and the clay is cone
6 stoneware. The cone slumped right over and touched the kiln shelf so I
know it fired to cone 6 (maybe over?). This was a slower firing than I
normally do with a 2 hour soak at full temperature. My wide rimmed plates
came out slumped almost to the kiln shelf.
Can anyone fill me in? I won't fire so slow in future with this clay but I
think I will keep the soak as my glazes didn't pinhole as much with it and
the clay seems to seep less.
Thanks for the help in advance,
Michele Hoskin
Toronto
Wilkinson on fri 5 mar 99
Michelle, It has been my experience when it comes to slumping plate rims
the cause has been uneven drying or how the rims were formed.
If the top of the plate or rim is dried quicker than the under side, the
clay will pull and may even crack. Since clay has a memory, sometimes if a
rim is altered it will try to go back to its original shape or direction.
Drying slowly and evenly may help to avoid slumping.
Lori Wilkinson
>----------------------------Original message----------------------------
>
>Hi everyone!
>
>I have been throwing large plates recently with very wide rims.
> Occasionally these rims need propping during the drying stage but often
>they rise and need to be pressed back down to horizontal.
>
>In the bisque kiln, I have stacked them in twos rim to rim. The rims seem
>to droop slightly after this and I wonder if it is due to the stacking?!
>
>I have just begun to use cones with my kilnmaster kiln and the clay is cone
>6 stoneware. The cone slumped right over and touched the kiln shelf so I
>know it fired to cone 6 (maybe over?). This was a slower firing than I
>normally do with a 2 hour soak at full temperature. My wide rimmed plates
>came out slumped almost to the kiln shelf.
>
>Can anyone fill me in? I won't fire so slow in future with this clay but I
>think I will keep the soak as my glazes didn't pinhole as much with it and
>the clay seems to seep less.
>
>Thanks for the help in advance,
>Michele Hoskin
>Toronto
>
Linda Blossom on fri 5 mar 99
Hi Michelle,
I was wondering how wide those rims are. You said they slumped almost to
the shelf. I usually dry a piece with a wide rim upside down. I never have
a problem with them sagging and if I were you I would consider the
temperature the culprit. It does sound too hot.
Linda Blossom
2366 Slaterville Rd
Ithaca, NY 14850
607-539-7912
blossom@twcny.rr.com
-----Original Message-----
From: Michele Hoskin
To: CLAYART@LSV.UKY.EDU
Date: Friday, March 05, 1999 8:51 AM
Subject: slumping plate rims
>----------------------------Original message----------------------------
>
>Hi everyone!
>
>I have been throwing large plates recently with very wide rims.
> Occasionally these rims need propping during the drying stage but often
>they rise and need to be pressed back down to horizontal.
>
>In the bisque kiln, I have stacked them in twos rim to rim. The rims seem
>to droop slightly after this and I wonder if it is due to the stacking?!
>
>I have just begun to use cones with my kilnmaster kiln and the clay is cone
>6 stoneware. The cone slumped right over and touched the kiln shelf so I
>know it fired to cone 6 (maybe over?). This was a slower firing than I
>normally do with a 2 hour soak at full temperature. My wide rimmed plates
>came out slumped almost to the kiln shelf.
>
>Can anyone fill me in? I won't fire so slow in future with this clay but I
>think I will keep the soak as my glazes didn't pinhole as much with it and
>the clay seems to seep less.
>
>Thanks for the help in advance,
>Michele Hoskin
>Toronto
>
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