Helvi Abatiell on sun 28 nov 99
Hello All! =0) I've been making wine goblets for gifts. I'm using a
#20 Laguna terracotta ^04 lowfire body, firing electric in my Paragon digital
kiln, using GL 612D 'Dip 'n Done' Dipping glaze which I've been brushing on,
and coloring with Concept underglazes. (I know how you clayarters like
precision in the details.)
My problem is that they seem to be crazing after about 3 weeks of sitting
on the shelf or after about 2 uses (so far, I've personally noticed it
happens immediately with a nice merlot). Am I posioning myself, my friends,
and my family? Is there some way to fix this problem in the future with my
current glazing routine? Or must I ferviously learn glaze chemistry
techniques and throw away (take the almighty hammer to) all those nasty
goblets before I fire my kiln again?
Any thoughts on this one?
Helvi
p.s. by the way, my stems don't bend on me.
Cindy Strnad on mon 29 nov 99
Helvi,
The stems probably wouldn't bend in low-fire if they didn't bend during
drying. As for the glaze, it's harder to get a good glaze fit in low-fire
clay. I'm not familiar with the glaze you mention, but many commercial
low-fire glazes do contain lead or other dangerous chemicals. All the same,
your goblets are probably at least as safe as lead crystal, whatever amount
of lead may be in the glaze. (In other words, not all that safe.)
To solve the problem, you can learn to formulate your own glazes and
experiment until you come up with one that doesn't craze, or you can
experiment with different commercial glazes. A freeze/boil test will cause
crazing sooner, as will early removal from the kiln. This will help you
figure out more accurately whether the glaze will craze with time and use.
Alternately pour ice water (or place ware in freezer for a time) and boiling
water into your test piece. Repeat, say, ten or fifteen times, and see if it
crazes.
Hope this is of some help,
Cindy Strnad
Earthen Vessels Pottery
Custer, SD
| |
|
