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knobs /glaze scratching/crazing

updated tue 31 dec 96 on fri 6 dec 96

First the knobs:
If you haven't been having cracking showing up as the knobs dry, then you're
starting your bisk firing too fast. Make sure the pots are REALLY dry before
heating them. Use a mirror next to the spy to detect moisture still lurking
in the pots before turning the kiln up from low. Try putting a fan on them
before loading them into the kiln, or storing them in a really warm place.

Now the glaze marking:
Try Temple white, the work horse of all glazes. It doesn't mark at all. It
fires semi matt to semi gloss, cone 10 soft to down
Temple White
Potash Feldspar 35
Dolomite 19.7
Whiting 2.6
EPK 22.7
Flint 20
Add Bentonite 2 percent or use borax for suspension.

Marking is something customers shouldn't have to deal with, especially at
stoneware temps. And this glaze DOESN'T craze on my clay body:t-3 from
Sheffield. I have pie plates I've used for over 10 years without one craze.
Good luck!
Jennifer in Vermont
Thistle Hill Pottery
Montpelier, VT