Lava rock kiln

[kapohokent]

I would like to make a kiln for pottery and was wondering how it would do using lava rock instead of firebrick, etc.? Anybody know of any made that way?

[TomK]

Not an expert in the area at all, but lava rock also contains minerals which might melt at lower temperatures than firebrick. What sort of temperatures are you talking about?

[Carey]

even more dangerous is that some lava rock tends to explode at higher temperatures. Rocks selected for an Imu are mot just random rock because for the tendency for the rocks to explode &/or break apart....neither would be good for kiln...

[Peter Epperson]

I used lava rock to make my brick oven http://pacificgunite.com/wood_fired_lava_brick_oven.htm
Whether you use rocks or fire bricks, you will need to slowly cure a new oven, or kiln, over a weeks time with increasingly hotter temperatures to avoid damage. My oven regularly gets up to 1000 degrees with no problem. I don't see why it couldn't go much hotter when you consider the temperature of lava flows.

[Guest]

Peter, that is soooooo cool !

What process with did you make the lava bricks ?

[Guest]

Some of this lava is mailed and shipped back here to the big island, hundreds of rocks a year. WHY?. Profit minded may be good, yet education may be better?. Here is another tip for those who may care?. Please do not stand or touch or even rub or piss against our precious coral reefs. They are sensitive and die easily, They can take hundreds of years to grow and can die in a matter of one year if the un-educated decide to swim.

[Rob Tucker]

Beautiful oven Peter. I have always respected the quality of your work and expertise.