Dale Neese on sat 15 oct 05
In all the years that I have been throwing pots I have yet to encounter "S"
cracking. I pay attention to the bottom of the pot on every pull. Even on
pots thrown off the hump, small or large. I theorize that compressing and
removing excess water from the bottom on each pass in the forming process
eliminates "S" cracks. With some of the throwers once the form is opened be
it for a bowl or cylinder, not much attention is revisited to the bottom
center of the pot. Compress center out as well as wall to center in the
bottom. Then pressure is applied into the foot on the outside at the wheel
head, pushing clay IN and UP into the wall thereby eliminating the need to
trim excess clay from the base later. The result of this neglect are pots
with "S" cracks in the bottom that feel like a boat anchor.
The tendency for some clay throwers is to continue at the inside wall after
opening and the first pull, neglecting the bottom thereby leaving excess
water and a bottom that has only been compressed once since opening.
With pots off the hump they may need to be trimmed if one doesn't press in
or remove excess clay from the outside before cutting it off the hump. Even
with doing this I will turn the hump pots over and compress across the
bottom with my fingers after trimming so that the bottoms are compressed
inside and outside preventing the "S' crack curse.
Then drying those bottoms...cut the pot off as soon as possible from the
wheel head or bat. Trim and place on layers of newspaper to dry slowly cover
loosely with plastic. I never dry pots on their rims which can bring about
other possible problems. ( cone 10 bowls warping in the firing).
See ya'll at the Texas Clay Festival next weekend!
Dale Tex
"across the alley from the Alamo"
San Antonio, Texas USA
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