Lili Krakowski on wed 25 aug 10
I think most "ideas" have been given.
However.
In a small kiln there often is just one shelf. In a big kiln there =3D
often are four or five "floors" That can affect heat circulation as =3D
well as heating and cooling.
Some glazes blister because they have not had time to heal. Suggesting =3D
too quick cooling. Others blister because they are "in fact" =3D
"overcooked. Slow cooling is great for some glazes--magnificent if you =3D
see some of Carol Marians's results. But I have had glazes that want =3D
rapid cooling.
Also: And this the Big Guys will have to figure out...I am not sure how =3D
wall thickness translates in cooling time. I intuit, but no more, that =3D
a 20" diameter
"drum" surrounded by 2" of brick cools differently for a 36" diameter =3D
"drum" surrounded by 2" of brick. (But then the only reason I did not =3D
flunk college geometry is that the teacher was the only one who taught =3D
it, and she could not stand the idea of having me as a student =3D
again....I always got the right answers, but never the proper =3D
explanations. "Just looks right!" did not wash.
Question: Do you fire same type pieces in big and little kiln? If you =3D
fire demi-tasse cups and bud vases in the small kiln, but Sauerkraut =3D
crocks and butter churn in the big one, then the clay thickness of =3D
little pots differ (be thinner) than that of humongous ones. In which =3D
case you may need to give the churns and crocks a longer slower higher =3D
bisque...esp slow at start. There just may be carbonaceous matter left =3D
in the clay body which then disturb the glaze.
Lili Krakowski
Be of good courage
| |
|
