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5c ft. natural draft, wood-fired kiln... oh yeah

updated thu 5 nov 09


Mike Arnold on wed 4 nov 09

If you follow the link below to my blog you will see a rough sketch of
my five cubic foot kiln and a video of the firing. It is a wood-fired,
natural-draft, chamber kiln designed primarily off of a noborigama.

*disclaimer* I am about to say this was successful despite not quite
hitting my desired temperature because I expect with a few more hours
and a clear head it would have hit at least cone 9... excitement got
the best of me and I started the firing too late in the afternoon.

This is the smallest successful, natural-draft, wood-fired kiln that I
am aware of but maybe someone can point me in the direction of
another. It was constructed out of 1"+ thick clay slabs and covered in
2.5=3D94 to 5=3D94 of fiber blanket, using a brick firebox/base.

It was fired for approximately 11 hours and reached cone 7 on the
bottom and soft 8 on top. It definitely did not withstand the heat and
cracked significantly, yet I am happy with the results and it will
influence the design of a later kiln I plan on making out of homemade
insulating castable with a slightly larger ware chamber and more
control features=3D85 a damper perhaps?

I am aware that I broke a lot of rules as far as design, firing
schedule, and firing in general, which may have hindered the kilns
ability to reach temperature (besides not firing long enough) and
definitely played a part in its near structural failure, but it was a
learning experience and welcome any suggestions, recommendations, and

Michael Arnold

douglas fur on wed 4 nov 09

Mike Arnold
"'"+ thick clay slabs and covered in"
You look at all the 2x4's used to build a wall in a house and there's way
more wood used to hold up the drywall than is needed for the structural
loads on the wall.
In a similar way clay like gypsum dosen't bend so a 1" wall that 's thick
enough thermally isn't thick enough to keep the wall from bending.
It needs more support from thicker bricks, cement block, or castable

"I am aware that I broke a lot of rules as far as design,"
The chimney looks small. but the smaller you get the less the rules work.