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firing time and load

updated wed 29 sep 10


mel jacobson on tue 28 sep 10

having just finished the third set of dishes, i have good evidence
about load and firing time. feriz delkic has always been very firm
about knowing load vs. firing time...nils has written about it at length
in both of his books.

you do not fire just pots, you fire kiln shelves, posts, the inside surface
of the kiln and then the pots, and you even have to heat the air inside
bottles. the more you have in the kiln, the longer it takes. when all is
heated the same, the cones go over.

my normal stoneware firing, with large and small pieces takes about
9 plus hours...a full load of dishes, 15 plates, big and small 15 bowls
big and small, 15 mugs and then all the serving plates bowls etc takes
13 hours. all three firing have been 13+. i have almost all of my kiln
shelves in one firing. about 30 big shelves.

this last firing was with the three temmoku glazes layered, with a
wash of mel's orange added with an ear syringe. i try and keep the
kiln in neutral. i opened the burner ports a bit more for this firing
and it seemed to work better...all three sets of cones dropped at the
same time...11 half way over.

i will post the results on my website later this week.
i hope this project is done. it has been daunting, but
really a great project. it does test your professional
place in things. the first two firings have been perfect.
not a waste pot in the bunch.

from: minnetonka, mn
clayart link:
new book: