Upside down?

[dmun]

Has anyone considered building at least the top half, the difficult half, of the oven upside down, in a form, maybe a cut-into-the-ground depression in advance of digging your footings? I don't think the traditional fireclay-sand-portland mix would be strong enough to hold it together while being flipped, but for anyone considering at least a semi cut-to-fit dome would let you play with the fit and finish of the visible, inside part, of the dome where it was clearly visible, and accessable.

I was looking at a professional brick oven in a pizzaria the other night, and was thinking that the finish is so good on these that they must do something like that.

[maver]

Maybe the "cap" - the last 3 rings or so could be done that way, but that really isn't the tough part (at least it wasn't for me). The challenge was about rings 5-7 (roughly, this is from memory) where the ring was big enough that you could not support it with just one support. Once you get to the last few rings they are small enough that they are easier to manage and they tend to wedge together a bit better. I think if you made the cap upside down you would have a final fit issue also - as you saw with your dome the multiple seams proliferate variance from the plan. I think if I did it over again and wanted a more professional result I'd just be sure I had an assistant and maybe a better saw like you used rather than my circular saw with a masonry blade - then it would have been pretty easy to get better fits.

I still think the ease with which your dome went together really argues for your method - I don't really think the standing seams will be an issue - lots of refractory domes are built from components with standing seams where there are 4 or more wedges that come together to form the dome. With tight seams and refractory mortar it should perform well. Your standing seams are not vertical either so there is a force pushing them together. Shame you don't plan to cure it until the spring. If it cracks at all you should be able to patch the cracks like anyone else has with their brick ovens. Janprimus has been using his oven plenty without any chimney or vent.