clay oven

[GFW]

The more I read the more confused I become. My initial project was to build an "earth oven" using natural clay and sand, more research, no acceptable clay in the wild so a potter/oven builder recommended mix of Hawthorne fireclay sand and portland cement, 2:1:1. More info on portland cement and because of low temp break down and only advantage it seems is quicker setting, which I really do not need not sure I want to use cement in mix?? Now enters masonry lime into the mix, seems in some locations this has been mixed with clay sand mix to decrease shrinkage thus less craking and increase the longevity of this type oven. Any ideas?

Thanks
GFW

[dmun]

If you start buying potter's clay, the cost advantage of earth ovens disappears quickly in the land of cheap firebrick. As far as I can tell, the only advantage of clay ovens is cheapness. As far as mixing various amounts of portland and lime with the clay, well, you're pretty much on your own.

I'm not sure you're correct about North Carolina being devoid of proper clay deposits. After all, Josiah Wedgewood went to N.C. because of their supplies of high grade kaolin.