Thanks for the info, Thomas. The bus is stationary. I don't live in it at present. I Still have to gather more materials and cobbing in winter up here is not practical anyway. I might remove that section of wall and go against the actual bus wall which is steel with a thin rock wool insulation. I like the idea of salvaging ceramic blankets.
thomas rubino wrote: Is it permanently, or at least sort of stationary ? I hope so, as no clay construction will last long driving down a gravel road. ...
isolating the bell/bench from your floor is easily done with spaced clay bricks, laid horizontal, with at least 1/2" or more cement board on top. Some folks have put a foil layer down on the cement board to be sure.
Your wall would use the cement board as well though 1/4" would work. You could use ceramic blanket or loose perlite for insulating at the wall. The wheel well hump would be best covered with ceramic blanket too. (glass top ovens have a ceramic blanket that can be salvaged)
Floor temp under the bell or bench should be no more than 200F max, most likely more like 125F or less. Under the core your looking at 500+F or more. (note) the floor in a bell is not counted against ISA.
Your core should be built on a perlite or ceramic board base.
Yes, regular brick is fine as long as the riser is under a barrel.
You may find that unlike your inadequate wood stove, the barrel of a rmh may run you rite out the bus! They do get hot. 3/4 covering the barrel with cob helps control radiated heat.
One nice thing about a bell over a bench with pipes is ash buildup! Pipes must be checked and cleaned at least every season for sure. I'm thinking you could go several years if needed with a bell.
Why wait any longer ??? (other than its winter..) Try your hand at this , I'm sure there is nothing else needing doing on your homestead in the middle of winter :) Being warm … its overrated anyway... Right ?