Lili Krakowski on wed 13 jul 11
Someone wrote me off list. In the glaze fire, bare spots had appeared =3D
on mugs. The glaze was Tried & True, and had never done this before.
Leaving aside that a new batch of Tried & True might have been mixed up =3D
wrong, or used a new batch of an old, but variable ingredient, here are =3D
possibilities.
Bare spots can have several causes:
1.Dust on bisque. Wash bisque thoroughly. With bowls, mugs and =3D
like that make sure nothing remains on bottom inside. Particles can get =
=3D
in during trimming.. Bisque that sits around for months, can pick up =3D
dust from studio. I wash the bisque the day before glazing, so it can =3D
dry overnight.=3D20
=3D20
2. Grease on bisque. All too easy to get grease on bisque--from hand =3D
lotion, from sunscreen, from not washing hands after eating. Yucky as =3D
it sounds one can get stuff on bisque by sneezing on it. Many people are =
=3D
careless when unloading bisque kilns, or moving bisque around. They do =3D
not pay attention to the cleanliness of their hands. Grease will =3D
reject water--so when you wash the bisque look out for "bare =3D
spots"--spots that repel water.
3. Burnishing: This is sneaky. For one, it depends on the clay body. =3D
A coarser, open body is less susceptible, but a tight, very smooth =3D
(hence dense) body can be burnished accidentally. With mugs it might be =
=3D
that when one puts handles on one rubs the mug itself working the handle =
=3D
in. One might over burnish in trimming...then one generally sees where =
=3D
one has trimmed being more shiny than rest of pot.
Lili Krakowski
Be of good courage
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