[Cob] cleaner cob oven for the future - Joe's concept

[Joseph Kennedy]

Hi Guys,
 
I hope to make a cob oven/kitchen with some high school kids this spring.  My plan is to make a rocket stove feed tube and chimney (lined with vermiculite cob) that ends at the base of a thick (1/4" or thicker) round steel plate at 3 ft counter height (manhole cover? too thick?) which forms the floor of the oven (similar but not exactly like Ray's sketch).  Can cook directly on the plate, or stack bricks on it to raise cooking vessel so food doesn't burn on bottom (and also gets the food into the hotter part of the oven). I will drill holes around the edge of the plate to let the heat rise along the interior cob wall of the oven (Quebec style shape).  I will do a chimney  hole with removable tight plug, designed to fit a pan on top (use chimney heat for frying).  Will try to integrate the hot water tubing somehow.  
 
For me: welding?  Fuggettaboudit. (though I do love that little teardrop thingy - reminds me of a fifties spaceship - put some grooves on it and you could make the chimney output all swirly (like that German water guy from the 30's (Schlauberger?))). 
 
Lots of vermiculite cob on top.  Counters with wood storage underneath.  Designed to fit nicely under a premanufactured metal roof (anyone know where to buy a silo roof?).  I would form the cob oven the usual way: sand form on top of the metal plate, 4-5" cob over that, 4" (sides) - 12"(top) vermiculite cob over that.  Let it dry sloooowwwwly. Probably some metal mesh in there to help preclude cracking.  feed tube hole area = holes in plate area = chimney hole area (I think that's best - heating engineers?) 
 
It would let smoke into the cooking chamber, but that's ok with me.  I think it should work: can cook right away, but also have heat containment in the cob for baking.  This would be oven 8 or 9 for me.  Comments welcome.  I will try to sketch it if I can find an easy techno way to put it on line (I am still the luddite mudman at heart).
 
Best,
 
Joe Kennedy