Nikos Papadopoulos

what I can say is that the plan so far is to put approx 10cm of cob (common proportions 3:1-sand:clay) without straw (as it would burn?) around it

how long the heat is "on" I think its down to a lot of factors, so you cant really take it as a general outcome. As you said, the logic is that clay and sand act as a thermal storage mass, so gradually release the heat stored. If it lasts until the morning..

So Eric, have you done anything with this ? I'm also in the same position and wondering how much cob is useful, if the mixture should have more sand than clay (compared to normal cob proportions), if it should be built right on the stove or not...

I am sure that heating will take more time to be transferred to the surrounding since it will have more thermal mass around it, but it will also be retained more time and gradually released.

Any info or idea, greatly appreciated.