Lajos Kamocsay on sun 2 feb 03
I have a small home built ~6.5 cu ft downdraft propane kiln. I'm having
problems with too much reduction and uneven firings. I'm thinking about
rebuilding it, as I've vasted many lbs of clay and glaze.
One big question I have: is it possible to build an updraft kiln that would
fire evenly? With an updraft, I wouldn't need to have a 20 ft chimney stack in
my back yard, and probably construction would be easier as well.
Or should I stay with the downdraft design, and try to debug my current kiln?
I'll probably also replace the burner I currently have, I think part of my
problems is that I can't get a nice blue flame for my small kiln because it's
too large (somewhere around 500k btus). Maybe because of this I spend about 10
gallons of propane for a ^6 firing... isn't that too much?
So I'm thinking about investing into a forced air burner. That way I could
probably get away with a lower chimney, have better control over the kiln
atmosphere and save on gas.
Or should I stay with a venturi burner, like one of the Ransome burners from
I always have too many questions.
Any comments welcome,
Dannon Rhudy on mon 3 feb 03
> I have a small home built ~6.5 cu ft downdraft propane ....
: is it possible to build an updraft kiln that would
> fire evenly......
Of course it is possible to build an updraft that fires
evenly. Many commercial kilns, including ones made
by Fred Olsen, are updrafts. It takes a little practice,
but you can do it. If the kiln is really, really, small it
may be harder, since early heat might be uneven. Go
slowly, take notes, and it will work. Look at some
commercial updrafts, just to see what they've done.
Most have multiple burners, however. One giant
burner is not likely to get you where you want to be.