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west coast kiln firing problems

updated tue 20 apr 99

 

Mason Batchelder on mon 19 apr 99


My friend, Peggy forwarded your message from the CLAYART group. I no longer
do pottery but I fired a West Coast Kiln here for 20 years. When I quit
pottery (went back to painting) I gave the kiln to Steve and Mario at
Tropical Clay and I believe they are still firing it. As to your problem, it
could be several things.
1) The kiln is built for reduction and reduces easily using only the top
damper. As you slide the top damper closed for reduction it probably
deflects some heat back down as flames start coming out of the peep holes at
that point. Soaking at the end always evened out the cones for me.
2)Although I specified which kind of gas I would use (propane) when I
ordered the kiln, our propane here seemed to be different and I eventually
switched to Venturi burners. My kiln had 8 burners around the outside and 2
in the middle. I always turned the middle burners down low for candling and
when I lit the outside burners, I left the middle ones on low. At any point
if I needed to even out the cones I could turn up the middle burners. My
kiln was always hotter on the top.
3)I had a hood built to West Coast's specifications and the chimney also, so
I think that had a lot to do with it. My friend who had the same kiln
without the hood and chimney did (and still does) beautiful reduction. Both
of our kilns were outside, but I had a roof over mine 11 feet up with the
proper hood and chimney. She put 2 coffee cans with the tops and bottoms
removed for her chimney.

Don't know if any of this is helpful, but I would be willing to bet it has
something to do with your chimney situation and the amount of draft . The
heat is not moving up as it should. Let me know if any of this
helps....Barbara Burger donbarb@aloha.net