Hi! Thinking about building a cast refractory dome oven.

[apachebrew]

I'm thinking of building a wood fired oven in my backyard. I really like the idea of a precast segmented dome. I modeled one in my design software and am contemplating 3d printing molds from PETG so that I can at some point cast them from refractory. I think I'll make a DIY vibratory table when doing this. I'm about 100 miles from the nearest HWI distribution center. I emailed them about my project and they suggested KS-4V Plus for the castable. I'm thinking of installing the dome on 4" thick calcium silicate board, then 12x12x2.5" fire bricks for the floor. Refractory mortar the dome to the fire brick floor. (2) 2" layers of ceramic fiber insulation, 2" perlite render, and then a layer of finish stucco over that. The ID of the cooking surface would be 40". The shape of the dome wouldn't be perfectly hemispherical, rather someone elliptical with a 17" internal height at the center. 8" flue. I dont know if there's a lot of cost savings in this approach. I was kind of just wanting to see if I could do it, and then be able to cast a few domes for some friends too. Does the design/material selection look ok?

[david s]

Your plan looks pretty sound. What thickness are you planning on making the castings?
Because there is a huge temperature difference difference in the base and top of the dome during heat up and the corresponding difference in thermal expansion, relief from this stress can be achieved by making the top circular section much larger so it will receive the early heat first. If it is designed as a conical fit it can then expand a little and pop out at the top without stressing the side castings. Also,you should think about fibre reinforcing and burnout fibres. if you make your own castable you need to include burn out fibres. If you buy a proprietary castable, check to make sure the product contains them, if not add them.