help with making a dome. Other Oven Types Discuss help with making a dome. in the Pizza Oven Design and Installation forums; i think moisture from the first layer should be cured out before applying the thicker second layer. Just a guess ...

[JoeyVelderrain]

i think moisture from the first layer should be cured out before applying the thicker second layer. Just a guess but I think moisture from the first layer may get trapped between the two.

[dmun]

I would discount any advice on the use of refractory concrete from anyone who hadn't already used it, myself included. That said, I think any plan to move a thin shell of castable is doomed to failure.

This thread may yield some answers:

http://www.fornobravo.com/forum/f43/...uild-7866.html (My Cast Refractory Oven Build)

[cannyfradock]

Originally Posted by aaron4osu

-i made a base for the oven:
cinder block, 3/4" steel plate top, then 3 inches concrete over that.
i have a layer of fire bricks for the oven floor.
i plan on making the first level of the oven with firebricks on ends(going verticle) with a homemade dome on top of that.

my question is with the dome. would anyone see any problems with making a dome out of refrax mix using a metal oven top as a form? I have a dome shaped oven top, similar to a basic weber type chargoal grill but not as high. I plan on coving that with newspaper, which can be removed, or burned off later. then just cover the dome with refrax mix and rebarb. I also plan on leaving a hole for the chimney on one side. i thought after i get a thin layer, i would place thin nails in the refrax to gage the thickness all around the dome.
does this sound feasible? has anyone else used this technique? finally how thick should it be? I haven't decided how I will finish the top yet. I'll either build a block base around and cover inside with vermiculite, or just cement over the entire thing. I'll worry about that later though. I'm just concerned with the dome top now.
Thanks, Aaron

Hello Aaron

It seems like you are causing yourself a lot of heartache in how to deal with the metal form you are using to create your dome. If you are going to take on the task of building a wood-oven, then, perhaps you should consider using some other type of form before commencing the dome. There are many types available which can be easaly burned off in the first gentle firing. Myself, I used 12 pieces of cardboard (bought from my local re-cycling agency for £3) cut into half-moon shapes measuring 1 meter in diameter by 50 cms in height. These were interlocked into each other making 24 ribs of cardboard held in place with strips of newspaper dipped in a flour and water mix. This sounds very primative but........it worked. The form was as strong as an ox and as light as a feather and just easaly burned away in the first gentle firing.......and cost £3.27p including the flour!!!!

Whichever method you choose, I wish you the best of luck with your project. Oh......and don't forget to take lots of pics along the way, I look forward to seeing them.

Regards Terry (C.F)

[ThisOldGarageNJ]

Hi Arron and welcome to the forum

the metal dome is just used for the shape

You could slice your dome into 3 or 4 pieces... Put it back together with duct tape, then pull out each section seperately after your refractory cement cures... You of course would have to build an outter ring of masonite or 1/4 plywood (well supported) to hold the cement around the dome,, Things to keep in mind, where is your door/chimney going etc,

Cheers
Mark

[Neil2]

"The differences in expansion rates will most certainly cause severe cracking. "

I agree with RT. I would avoid using rebar or mesh in the dome. Also, the dome should be cast monolithicly. Successive thin layers will not bond to each other with anywhere near the strength of a full depth pour.

Have you considered casting in segments (similar to the Forno Bravo precast units) ?