I just built a oven using a rocket stove for heat. All materials were rubish nothing purchased. This build uses 2 old air compressor tanks. One tank is the oven completely sealed from the outer tank so no smoke in the cooking chamber. This isnt going to cook 90 sec pizzzas but will hold a good temp with little wood. The first fire up took 25 min to get to 400degrees. Maybe some insulation on the top of the oven will help with pre heat time. There is a lot of steel in this thing probally weighs 50 or 60 pounds. Had a fire going for 2 hours and used a hand full of wood. Cooking surface is 10 x 16
Mike Gee : Great Rocket Stove,modified to make a baking oven, with a little support from below a little structural /insulating Cob with straw should give you all the insulation to
get you into the ' 90 sec pizza zone ' Whats your next project / pictures ? Big AL !
Success has a Thousand Fathers , Failure is an Orphan