Undetermined origin c/o LISTSERV administrator on thu 22 jan 04
Dear Lou Roess,
You will need glove if the pyrometer is reading 212=BA F.
People who like to crack the kiln early seem to forget that the =
pyrometer is reading the temperature of the air in the kiln, not the =
ware. So the ware is always hotter at the surface than the air which =
surrounds it. and it follows that the interior of the clay is hotter =
than the surface.
Pinging can be due to the sudden contraction of the skin of the pot as =
it is chilled when cold air invades the kiln space. Stress imposed is =
greater than the tensile strength of the glaze coating.
If you chill your bisque the cracks remain in the fabric of the clay and =
can be a source of future failure. Many of us have found hairline =
fissures open up during glazing.
Try to be patient.
Best regards,
Ivor Lewis. Redhill, South Australia
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