Jonathan Kaplan on wed 11 oct 00
In my humble experience, and most ceramic engineers/technicians, and those
working in industry will concur that probably 99.9% of cracking problems
are the result of improperly dried ceramics.
Potters often pay too little attention to proper and thorough drying in an
attempt to move the work though the studio in a timely basis. Most clay
bodies are not designed for fast drying and then with the additional
variable of adding knobs, handles, spouts, etc. all these set of a moisture
differential throughout the piece. Of course ther are always going to be
clay bodies that are problematic..........
Drying a piece correctly implies the total removal of the mineral water at
a constant rate so that no stress occurs in the ware. Perhaps if we all
took another look at how we dry our wares there would be fewer seconds.
We bisque all our ware (with the exception of low temperature white
earthenware bodies) to cone 06. Our rate of climb is 250 degrees per hour
in the electric and gas kilns. We soak all our bisque firings for 30
minutes at the end to even up the temperature in the kilns. Our white
earthenware is fired to cone 04 with the same rate of climb and the same
soak at the end.
Jonathan
Jonathan Kaplan, president
Ceramic Design Group
PO Box 775112
Steamboat Springs CO 80477
voice and fax 970 879-9139
jonathan@csn,net
http://www.sni.net/ceramicdesigin
Plant Location:
1280 13th Street Unit 13
Steamboat Springs CO 80487
(please use this address for all deliveries via UPS, comman carrier, FEd
Ex, etc.)
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