Janet H Walker on thu 23 oct 97
...However when I did my first bisque firing using the
04 self-supporting cone in the slow 12 hour mode,which took all day
yeaterday,opened it this morning,finally,the cone had not gone
over...
There are a few things to work on as part of learning to fire with
a controller! First off, your load of bisque is probably just fine
to glaze, assuming that you are going to fire it higher than 04. It
more than likely got hot enough for your purposes even if the cone
didn't go over.
A few loading tricks:
- Until you get used to it, put self supporting cones on several
shelves throughout, not just near the peep holes so you'll convince
yourself that things are pretty even throughout. (And by the way,
those things have quite an arc to them so put them so that they will
be well away from a pot when they go down. Guess who learned the
hard way...)
- It matters a whole lot where the shelves go relative to the
pyrometer for the controller. I try for at least two inches above
and below, going with more space above the pyrometer if I don't have
a choice. If you crowd the pyrometer, it is going to register
higher than the cones think it is.
And a firing trick:
Never hurts to add a soak period at the end of a bisque. In fact, it
can help quite a bit to get the last vestiges of nasty stuff burnt
out of the pots. Some older texts (Norton) recommend one or two hour
soak for a bisque. They were undoubtedly working with bigger slower
kilns so it is probably even more important for a kiln with a high
ramp at the end like these little electric guys on the controllers.
Have fun with it. And don't be afraid of the programmable mode
either when you get to glaze firing. I have gotten my best results
by using a controlled cooling period after a soak instead of just
letting it turn off.
Jan Walker
Cambridge MA USA
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