Vince Pitelka on sat 8 nov 97
>While I was firing my gas kiln to Cone 5 my cone pack exploded and I was
>unable to read the temp. My pyrometer is not reliable. Anyway, most of
>the load has not matured and I'm wondering how successful a re-fire will
>be. I'm also wondering how successful a new dip of glaze would be if
>it's added to the pots and re-fired.
Allison -
The degree of success in refiring depends on what temperature you fired to
the first time. If you shut off the kiln very early, or if you fired up
close to the normal maturing temperature, then you will be OK. If you
stopped somewhere inbetween, you might have some trouble. But you can tell
from examining the pots. Is there any sign of the glaze cracking away from
the surface? If not, you are probably OK, and can refire the load. Why
would you want to add more glaze?? Just refire the pots as they are. It
should work out fine.
Now, regarding the exploding conepacks - this is going to sound cocky, but
I'll risk it. My cone packs are perfect. In almost thirty years in clay I
have never had one of my own conepacks blow up, and I fire them green, and I
often fire them fast. Roll out a coil of clay no thicker than 1/2" in
diameter. Flatten it slightly. Set a cone on a flat surface and observe
the angle at which it stands. This is the angle at which it should be
placed in the cone pack. Press each cone into the coil until it won't go in
any more. In other words, press it in until it displaces almost ALL of the
clay beneath it. Put the next cone DIRECTLY adjacent to the previous one.
Place the rest of the cones similarly. Pinch the clay between each cone to
help lock them in place. Poke about a zillion holes into the clay with a
needle tool, especially in the larger masses of clay between the cones and
at the ends of the cone packs. Don't mess with wedging vermiculite into the
clay for cone packs. It makes the clay less plastic, and they can still
blow up. Put the cone packs in a warm place to dry thoroughly before using
them. Good luck.
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
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