debkaplan3 on fri 22 jun 01
-----Original Message-----
From: debkaplan3 [mailto:debkaplan3@email.msn.com]
Sent: Friday, June 22, 2001 8:27 AM
To: Ceramic Arts Discussion List
Subject: RE: warping woes
Hi all
Plates warping is a problem that I have had & still do, however, I am
increasing my perfect plates from 1 good out of 3 to 2 out of 3 for my large
platters ( 13-14 sq. inches) & 8 out of 10 for my medium ones (10-11 sq")by
doing the following;
1. Let them dry more slowly ! There is so much surface tension in large
flat pieces that any uneven drying can cause warping (lifting up of the
areas drying too quickly). The goal is to create a an enviroment where the
whole piece can dry at the same rate. So dry over the mold with plastic
under it & over the plate over night. The plate should firm up due to
absorption of water by the mold. Remove the plate & place it on a ware board
covered with plastic under, then cover the plate with plasic & tuck under
the board. I then let it dry several days loosening the plastic alittle
each day. This process takes about a week.
2. Make the plates thicker. My thicker plates warp less however the
platters take a couple of weeks to dry.
3. Don't use plate setters. They just increase the tension. A flat kiln
shelf, or one supported with pieces of flat bisque (I use little tiles) &/or
what Logan suggested a little grog sprinkled on the shelve work wonders.
I sold a platter recently for $125, but no one would touch the slightly
warped one. So to me it is worth the TLC
Fondly
Debbie Kaplan
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of Nancy Galland
Sent: Thursday, June 21, 2001 1:57 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: warping woes
I am getting discouraged and I wonder if anyone out there can help figure
out what is happening to my oblong shaped plates. They warp a lot. If you
have the attention for it, here are the details:
I am working with cone 6 porcelain. I had been using stoneware, which
hardly ever warped, but since the dioxin news, I have not been able to find
a stoneware that has no ball clay.
I slab roll it ( a Bailey, with 2 rollers), cut it to size, smooth off the
canvas marks with a plastic rib, put a cloth over it, flip it, smooth that
side; then I place a bisqued mold over it and flip the sandwich over so the
slab rests in the mold. I then smooth out the bottom, pressing around the
flat area with a damp sponge. I let that set for several hours and then
remove the plate from the mold by holding a flat piece of styrofoam under
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