I was lucky enough to get second-hand bricks from the old
coke ovens at Union Bay on Vancouver Island most of which
have a slight taper (ideal for building a shallow arch) the
coke ovens being of the bee-hive type. We used over 3000
fire bricks in the construction of the kiln plus stack.

Cost of kiln incl.stack: less than $1,000.
Cost of Propane Installation incl. burners: over $400.

Firing:

Cost per

I use 6 venturi type bumers on the glost chamber and 1 on
the bisque chamber with a maximum capacity of over 2 mill-
ion B.T,U, 4 burners fire against a 24" baffle wall made of
carborundum shelves about 5" from the wall at one end of the
glost chamber, 2 more are facing each other at the other end
close to the entry into the bisque chamber.

The flue extends into the first chamber so that it can be fired
independently. The entry into the flue can be opened during
the firing in order to draw the heat down to the bottom of the
kiln which tends to be cooler in downdraft kins. This way
the temperature evens out beautifully and a variation of more
than one cone is unusual.

I light up at 8.00 in the morning and reach a good cone 9
between 10.00 - 12.00 p.m. depending on the weather,
stacking, etc. I used to reduce slightly by introducing ex-
tra gas through pilots from about cone 1 almost to the end
finishing up with oxidation. I now seem to achieve the same
result by reducing heavily for 2 or 3 periods of 15 minutes
each during that same time by putting on pilots, closing down
primary air intake completely and damper slightly - this way
using much less gas which is an important factor to consider
as the transportation cost of propane makes it rather expen-
sive (almost 10% of product).

Firing: $20 - $25. I fire every two weeks. - I use mostly
wood ash glazes and I am quite happy with the results.
Don't feel I could improve much on my kiln.

Heinz Laffin