David G Brown on sun 6 oct 96
I received an inquirie on sawdust firing in an old gas kiln. Perhaps some
of you would be interested in my response. Also please give me feed back
on the ideas that follow:
I was actually refering to a regular natural gas kiln; but, there is no
reason propane would not work as well. It sounds like your budget is tight.
Since the temperature is fairly low you might try scavenging burners from
propane appliances such as stoves, heaters and water heaters. I am going to
try using the burner from a forced air furnace. It is a manifold with 3
venturi burners rated at 100,00 BTUs. Whereas kiln venturi burners are cast
iron, these are stamped steel. Instead of one central flame at the end of
each burner they are extended and have a row of holes along the top. I plan
to cut off the end with the holes to create one large flame from each. Of
coure they will not stand up to high heat for long but hopefully they will
make a free raku burner.
Be advised that propane burns much hotter than natural gas at equal
volumes. This means the oriface size for propane is smaller. Propane
suppliers may sell conversion parts for changing a natural gas appliance to
I have also seen plans for making a kiln fueled with used automotive oil.
The burners were made from inexpensive plumbing parts and a fan.
You may be able to get firebrick from commercial potteries that have to
occasionally replace the brick in their kilns. They either sell it
inexpensively or have to dump it.
To get back to your non-kiln firing, it is only neccessary to maintain
enough heat to keep the sawdust burning. That means 500 degrees or so
should work. If you can build a "kiln"( container) that enclosed the
sawdust sagars, had a port/openning through which the flame entered and
there were enough ports to allow combustion air in and an openning at the
top it should work.
Without knowing your knowledge and circumstances better I am not sure what
more to say. Let me know what happens and feel free to discuss whatever
Redwood City, CA