rocket mass in clay bath?

I'd like to put in a large clay bath on one of our mineral claims, which
contains considerable glacial clay from the most choice mountain complex in the
region.*

If anyone has built one I'd be interested to learn how you did it.

I'm thinking of three rounds of swedish-cope scribed logs bolted together.
Filled, it'll be about 14x9 feet and 30 inches deep.

I want to put a rocket mass heater in there, including the bell and a horizontal
chimney, to heat the mud mass with. A piece of well casing would be perfect for
the horizontal chimney. We'll have to waterproof and prevent slumping of the
cob, maybe with cement or layer of lime, to prevent re-suspension of the clay
covering the heater. Clay bath will be filled by hand and emptied by raising a
guillotine valve to let the mud out of the low side of the bath.

I'm not against a permenent cement bath and I can do one, but until we convert
the mineral claim to a more permanent mining lease, which confers the right of
occupation, all the works have to look temporary.

So, do you know of anyone who has built one from earth, logs, or cob?

* (Seriously, check out http://tinyurl.com/Bella-Coola-strain-geology figure
1.2, the most choice Mt. Saugstad area and our valley draining it in yellow, and
the red Bastille Peak cirque within it. "Post-tectonic" plutonic intrusions are
excellent host rocks for medical clay. As Jason points out, regional differences
are what make a clay unique, and our deposit is rather unlike other glacial
marine clays in that it originated practically right where it's bedded, while
marine clays from farther out on the west coast are a blend of the much larger
area of the outer coast ranges and ocean floor so contain much more clay made
from lava and volcanic ash and their specific minerals than the mountains of our
deposit do. Let's have a look at an analysis hopefully in July.)

all good,

Duncan Crow
Timbersmiths Log and Earth Works
Hagensborg BC