Cob: bench heater

[kajchr]

Hi, I am new to this list but I have been on the SB-list for a couple of
years.
I want to build a rocket/bench heater. I have no problem in the principles
or the work itself. My question here is: I would like to try building the
combustion chamber itself in cob - if it can take the heat it´s very
low-cost, and I like that. I wonder if anyone else has tried that? How much
heat can cob take before it goes to pieces? I would like to hear about
other people´s experiences but I am going to test my idea no matter what. I
already made a small model that I´m going to put in the hottest part of my
Finnish Mass Oven to see what happens.
(I am aware of other heaters and ovens being built of cob, but they don´t
reach quite the same high temp.s)

Regards and lots of Merry Christmass´es

Kaj Lauritzen
Denmark