it's been about three months now that I have been doing some occasional research on different types of pizza ovens. At this point I can safely say I have read just about every Fred I could find in this forum along with many of the great sides that people have linked to and of course watched tons of YouTube videos.
Because there are so many different ways of building is, the most important stage was defining what exactly I want.
Overview of my aspirations for the oven:
-decently higher temperatures from above and below to make excellent pizza 400°C would be ideal
-Heat retaining qualities to last me at least one round of the baking bread, circa one hour of 200°C
-Because I won't be having many parties catering for 50 people, I don't want to spend hours preheating the oven, maybe 45 minutes would be good. This is also a factor in fuel consumption, I'd like to be able to make a few pizzas and two breads without using tons of wood.
-I don't have welding experience although I could find a friend if necessary, But prefer without.
-I would like to reuse A large 200 L oil drum that I have for the shape and I am hoping to build primarily from cob, Stone and tile debris and rubble and get away with only having to buy the firebricks and some small things if necessary. i have a small amount of cement here aswell.
wisners double chamber:
i have studied the wisners double chamber cob oven in detail and for my purpose it might take too long to heat up and is more suited for frequent use. however it is on my list of possible solutions. they mention the possibility of reducing the outer shell for faster heating but thats coming down from an original 2h heat up time.
traditional pizza oven:
i have studied traditional ovens and their dimensions, which again is fantastic but takes long to heat and is not taking advantage of rocket/reduced fuel possibility.
hybrid rocket cob oven:
then there are the hybrid rocket cob ovens that often have the riser come up right at the center of the hearth, where it seems to me that of the hearth gets too hot, its too cool at the top and the hearth often doesnt withstand the brutal direct heat. they also seem like one of the more challenging builds.
fancy new tech portable pizza ovens like uni 3:
using part of the rocket principle to draft the flame along the top of the oven and over the pizza and the stone, resulting in high temps above and below in short heat up. downside: unsuited for baking, expensive and my garden doesnt grow pellets.
i'm wishing that you guys, who i can see have vast knowledge and experience with rockets might give me feedback on my plans. my idea is to use a rocket for fuel efficiency as a hybrid or the uni do, but combine it with a not too deep cob insulation to give me the ability to bake. i'm adding a chimney at the front like ernie and the uni to draw smoke out the top and am considering (not sketched) a 2nd bake door like ernies. the deflectors are an idea that came again from uni and from a sketch by satamac.
1 what do you think i can use to line the inside of the drum and even lower the height on the inside with. clearly it needs to be lowered for the design to work. the difficulty there is sctructural, so it doesnt just collapse. could cob work and how could i maybe suspend it?
2 what can i use a binding slur in the base together with rubble, stone, tile and glass debri? cob slurry, cement or a mix?
3 the heat riser will not be insulated with sawdust and ash as in the sketch. i read all about metal in heat risers and its obviously not the way to go for longevity and food safety, so i'm thinking on molding a cob riser or just fire bricking it up.
hugely appreciate your help and criticism, i'm just hoping to finally settle on a design and get started.