pizza oven becomes a kiln

[david s]

I am building a stoneware kiln using my cast oven design.I have cast a cylinder in three interlocking pieces atop a two piece floor. There is 50mm of calcium silicate board and one inch of perllite/fireclay under the floor. I had difficulty obtaining a lightweight castable so decided to make my own using a dense castable with an aggregate that would burn out. My initial tests using 50/50 dense castable (with ss needles) and sawdust proved way too weak, so tried 50/50 rice, castable(with ss needles) which was just as bad. ended up using 50/50 crushed firebrick, castable, with ss needle reinforcing, which worked really well. The walls are only 35mm thick as the objective is high temp (1200 C plus) and economical fuel use. A dome in the same brew will sit on top. This is a downdraft design with the exit at floor level. The burner entry is from under the floor. I will cast three lightweight castable pieces for the door, to be placed each time the kiln is loaded, gaps sealed with a 50/50 sand, clay mix. I plan on a 5" diam. ss flue with damper.The kiln size will be 4 ft3 fired with a single LPG burner.

[david s]

Have mortared the walls and dome in position and one layer of blanket. Having trouble finding the time there is so much else to do.

[cobblerdave]

Davids
Will the oven be insulated like a pizza oven? And the heat source? fired by gas? Know nothing about kilns...so I'm watching with interest. The position of the chimney is an eye opener.

Regards Dave

[david s]

Originally Posted by cobblerdave

Davids
Will the oven be insulated like a pizza oven? And the heat source? fired by gas? Know nothing about kilns...so I'm watching with interest. The position of the chimney is an eye opener.

Regards Dave

Yes, it will be insulated. A few more layers of blanket, then perl/vermicrete and a rendered concrete outer shell. It is a downdraft design so the flue entry is at the bottom. And yes LPG fired with a single burner.

[david s]

Blanket and first layer of vermicrete started. My fingertips are a bit raw so I'll leave it for a few days. Actually that's a bit of an excuse, it's really because it's 34 C here now and the aircon is a more attractive option. After two weeks in sub zero temps in Japan the tropical summer heat is a shock to my old body.

[Sananguero]

Very interesting build! Mahaloz for sharing... what will you be using the kiln for? I wonder if anyone on the site has built a kiln for drying wood...

Karl

[david s]

I will be using the kiln for firing reduced stoneware pottery.

[david s]

Got a little more done on the kiln. Have now finished the first layer of vermicrete. It is so wet here ATM. Some rain every day and constantly , hot, overcast and humid, not good conditions for trying to dry vermicrete.