I aborted my firing last night after the kiln stalled for more than 3 hours at ^3/6 (side-to-side unevenness; that part was not unusual. It evens out later.) It hasn't done that for more than two years, since I corrected the height of the bag wall!
Needless to say I was grumpy but I am guessing weather conditions are the cause: Here in Central Maine we were experiencing sustained high winds almost steadily for the full duration of the firing. My thinking is that the wind created such a strong draw - on a kiln that is already inclined to draw too hard - that the hot gasses were just being sucked out of the kiln before they could heat things up. I will re-commence firing on Wednesday, and we shall see what we shall see.
While I was looking for some online confirmation - someone else who had had a similar experience - I discovered this really great discussion by Vince Pitelka on firing. It seems to be about a specific kiln at the Appalachian Center for Craft, but much of it is applicable to firing any reduction kiln. If anyone is curious about reduction or any other gas firing, I just wanted to direct them to this great resource - and to say again thank you to the giants among us who are willing to share.
I know how you feel, even though I'm just using a little electric kiln, I had to shut it off during the last glaze fire, since the top ring elements died. Which sorta sucks cause I just replaced them last fall.
ReplyDeleteGreat resource. If I were to return to reduction firing--and I think about it every day--I'd need a refresher course like that.
ReplyDeleteLike Michelle, I find the firing an electric kiln reliably, (no computerized set up here) is very challenging. My kiln is very small and since the variety of things I fire range significantly in size, I can't seem to work out patterns that would help me to have predictable results. I also just replaced the elements, so the timing is way faster and I haven't NOT over-fired since then.
But I agree with you Lori, the wind and firing do not make a good combination.
Michelle -If BOTH elements have died, check your relay for that ring. The relay may have quit; it is easy to replace. You might want to replace both or all three (depending on yer kiln), since they tend to fail within months of each other.
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