This is my second post...the first one I screwed up!
Anyway...I'm really glad I found this place and the RMH.
1. I would like to ask them about some of the different clay materials they've used over the years and how some clays measure up against others and what to look for in the materials used for making cob, fire cement etc? Are all clays created equal? I sure have lots of it here where I am.
2. Are there any refractory concrete mixes that they've used successfully? I've been thinking about pouring a small pad of refractory concrete, over perlite, to build the stove upon......or.....
3. Can an exisiting concrete floor serve as the floor of the burn tunnel? My intuiton tells me that it too would be subjected to too much thermal shock but I'll ask anyway...
4. Is there a better burn tunnel design? ie - Square or rectangular? I was planning a 6 x 6 burn tunnel in 7" system.