heating rocks

[603doug]

In my wood doc converter the flame exhaust etc is pulled down through the coals to burn the gases, their version of a gasifier, and I love it. Now I am building a sweat lodge and stingy as hell on burning wood in an open pit. I am wondering if I put soft ball size rocks below the firebrick where it is the hottest would it heat my rocks plus not waste any wood

 

[Nofossil]

You run the risk of exploding rocks (good name for a band, by the way). Rocks often contain moisture, and the secondary chamber reaches over 2000 degrees. I've reduce a wide variety of high temperature refractory parts to gravel.

 

[603doug]

I was kidding just do not want to waste heat, we have built lodges before and you are so right on moisture content in a rock. We found out the hard way once, I would be the collector of rocks but I was out of town and a friend collected some fired them up and all you heard was rocks coming apart like welding on concrete, he had gather nice round stones from near a brook and they were like a sponge luckily the problem was in the firing pit not shrapnel inside the lodge

 

[Chris S]

That's an interesting reply nofossil, are you also a Dave Barry fan?

 

[Nofossil]

That's an interesting reply nofossil, are you also a Dave Barry fan?

I am a fan of a great many things.....

 

[homebrewz]

Use igneous rocks for sweat lodge fires, such as granites. Never use sedimentary rocks, sandstones, limestones,
and especially don't use shales. I know some people use limestone, but there can still be pockets of air and or
moisture trapped in the rocks.