Stephani Stephenson on thu 23 aug 01
Pat wrote
"I'm pressing 6x6 tiles with relief decoration.
Whats happening is certain designs get a crack in the
same spot on each tile.i'm drying them very slowly(2
to 3 wks).
My clay body is heavily grogged (25%)here is the
What i dont understand is that on some designs not one
tile cracks.while on another my loss is 1/3."
Pat, this is always kind of like the game 'Pin the Tail on the Donkey'
with blindfolds....
Hoping, without seeing the designs, to hit the right spot, and identify
the problem!
Is it possible there is a problem with one of the designs with regard to
the relief?
i.e. is the area where the cracking occurs near an area where there is a
sudden
change from deep to shallow relief? an area where there is a change from
thick to thin that might be more extreme than on the other designs? Or
an area that is very thick or very thin?
this would create a drying differential, also a 'weak spot' where a
crack might occur to relieve stresses which occurs during shrinking.
(i apologize, I am fumbling for words here...)
Anyway examine the design and the mold and look for these clues.
Look for ways other ways this design , this tile, differs from the
others where you have no cracking. Is there a size difference?
I hope you have successful sleuthing here!
sincerely
Stephani Stephenson
Carlsbad CA
steph@alchemiestudio.com
mudmistress@earthlink.net
http://www.alchemiestudio.com
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