Minne"snow"ta castable build....... I think?

[UtahBeehiver]

This will affect the performance of the oven. If you are spending the time and money to build a WFO do it correctly. It won't be "some" BTUs it could be significant. But I will let others chime in. We iterate often on the blog that the oven dome and floor need to be isolated from the concrete hearth. A possible option would be to pour a 5 to 1 p/vcrete ring around the base of the dome to insulate from the hearth.

[jakeanderton]

This will affect the performance of the oven. If you are spending the time and money to build a WFO do it correctly. It won't be "some" BTUs it could be significant. But I will let others chime in. We iterate often on the blog that the oven dome and floor need to be isolated from the concrete hearth. A possible option would be to pour a 5 to 1 p/vcrete ring around the base of the dome to insulate from the hearth.

Interesting. You are right, in that if i am spending all this time and money I want to do it right. A perlcrete ring wouldnt take too much effort. I just hate having to wait another 6/7mos to get back at it and start enjoying pizza. I need to see if someone has some form ideas that would allow me to construct in my house, then join together with refractory mortar.

[UtahBeehiver]

I does mean you need to take the pcrete ring all the way into the floor brick or there will be a gap between the floor and the inside of the dome. There have been a couple builds where they build the dome inside a garage for assembly later. Be aware it will be very heavy unless you segment the dome. Go search on Other Type of Builds for the projects. David S is our cast expert and he should give you some insight on doing this.

[jakeanderton]

Americana I sent you a message about your form material.

[jakeanderton]

I ended up being waylaid by a patio my wife wanted and built a mold in the basement. Casting the dome in 1/4 sections. Each mold is close to 200lbs and 3” thick, with mesh inside for reinforcement.

Me concern is that the weight of these would crush the perlcrete ring I would place under it. Thoughts?

[david s]

5:1 is ok, 10: is not.

[jakeanderton]

5:1 is ok, 10: is not.

I may go 4:1 for added strength. And the mix is straight Portland cement with perlite/vermicrete, or what else in the mix?

[david s]

The more cement you add, the less insulating the casting will be. (see attached table for explanation).
Adding a little (a handful for every litre of cement in the mix) powdered clay helps to get the cement to cover the grains. But this is usually only required for a lean (10:1) brew. Too much water will wash the cement off the grains so adding the correct amount is vital. add water and mix gently in a barrow (not a mixer) until the water pools a little in the bottom of the barrow.Allow plenty of time for it to dry out before building over it. (See attached experiment)


Vermicrete insulating slab PDF.pdf

[jakeanderton]

I’m working on my forms and plan to assemble outside in n a week or two. Regarding stove pipe and cap, anyone have good and cost effective recommendations? I’m guessing I need 7” or more in diameter and at least 36” high.

[UtahBeehiver]

Look at the FB Pompeii plans and recommended chimney size based on diameter is posted.

[jakeanderton]

UtahBeehiver Thanks. Seems my 38” is between an 8-10” ID. 10” just seems huge to me and will go with an 8”.

[jakeanderton]

Finally had the forms completed. However, with each piece weighing 180-200lbs, it was a pain bringing them upstairs.

once in place on the pad, I’ll be closing the joints with Sairset.

[jakeanderton]

Dry fit completed, filling the gaps with Sairset.