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wood kiln firing problems

updated fri 30 apr 99


William Brouillard on thu 29 apr 99

Excessive build up of coals in the fire box can be the result of more
than one factor. It might be wet wood, wood that is to large, too fast
or too heavy a stoking style, or insufficient air or draft.

I do have a little device that comes in handy for this problem. I call
it a mechanical mouse hole. It functions like the the mouse hole on a
Boury-Box style kiln in that it introduces air to the coals.

There are two versions, the cheap and the expensive. The basic design
is: a length of pipe, iron or stainless, the length of the firebox plus
a foot or two and a small blower, electric or hand driven. The blower is
attached to the pipe and the pipe is drilled with 40 or 50 small holes
down the length and around the circumference. The hole should be drilled
into the part of the pipe that fits inside the fire-box. The pipe should
be capped on the end opposite the blower. The blower should have an air
adjustment or speed adjustment device. Stainless steel pipe holds up
better than regular pipe.

When the coals build up push the pipe into the middle of the coal pile
and turn on the blower. Adjust the blower to put out a small amount of
air. Be careful not to use too much or the heat of the coals will melt
the pipe.

By watching the coals you should be able to regulate the burn so that
the ash pit does not overfill with coals. I have used this on many
stubborn kilns and with a little attention it has solved most of my coal
build up problems.