Carrie or Peter Jacobson on fri 14 apr 00
Hi Andie: What might be happening is that the expansion and contraction of
the porcelain in the firing process is not going smoothly. The material is
catching and grabbing the kiln shelf in some spots.
I have had success making little beds of alumina hydrate on the kiln shelf,
then placing the foot of the piece on the beds. After the firing, brush the
alumina into a container, and you can reuse it (the alumina).
Something I've found that works equally well, and which I like much better
(it's neater), is to mix alumina hydrate with some wax resist, in a little
bowl, and paint it on the foot before you fire. It is fine to do this before
you bisque, just paint it on greenware. Make sure to remove all the
remaining alumina off the foot before you glaze. Then put it on again, to
protect during the glaze fire.
The alumina acts as a bed of little rollers, allowing the porcelain to slide
smoothly while it is expanding and contracting.
Here is a question. Do you fire to cone 04 and then do a soak during the
bisque at cone 5? I don't understand what you are saying here. Must be the
aluminum, taking my brain cells away.
Carrie
In Mooseville
| |
|
