insulation question?

[tommy5]

i want to keep a low profile on my oven, i have a forno bravo casa 100, insulated with 1 inch of refrax on the entire dome and the 2x4 over the seams. then i put the entire roll of insulfax and there is about 4 inches of dry vermiculite around the dome. my question is the top would be hard to cover entirely with dry vermiculite, and keep the lines i would like. is there anything anyone can suggest, like maybe can i cover the top with a vermiculite/portland mix on top of the dry?

[arevalo53anos]

Do not need to be dry vermiculite.
To maintain the shape that you like, you could use a mixture of vermiculite and cement (most in this site like 6 parts of vermiculite for each of cement).
In my dome I use 8:1 with great results.
There is a thread of mine where there are explanations about the mixture work.
It is easy, and funny IMHO.

Luis

[james]

Luis,

As always, a very nice description and excellent photos. Thanks.

There are two cases where you can use dry vermiculite without mixing it with Portland cement. If you want to build a walled/gabled enclosure, you can pour loose vermiculite into the air gap between the insulfrax and the upper enclosure walls. Loose vermiculite is more efficient than vermiculite concrete, as there isn't any portland cement to clog up the air holes.

The second option is to build an Igloo enclosure using rebar and stucco lathe, where you "pour" the loose vermiculite into the air gap between the insulated dome and the exterior Igloo shell.

Tommy, if you can stick to the 1" Insulfrax blanket and 4" loose or mixed vermiculite layer above the dome, before you build your finished enclosure, you are in good shape. Does that work with your design?
James

[tommy5]

james,

it works with the front back and sides, 1 inch blanket, 4 inches dry vermiculite, my problem would come with the top, the position i would like my roof at would leave the top with maybe 1-2 inches,
tommy

[maver]

Double or triple up the insulfrax on top? As far as insulating value, 3 inches of insulfrax should be as efficient an insulator as 1 inch insulfrax and 4 inches loose vermiculite.

[james]

I agree with than. If you can find space for 3"-4" Insulfrax, you won't feel any heat on the top of the outer enclosure. I am becoming increasingly attracted to more solid-state ovens in general. SuperIsol below and Insulfrax above. Less mess and good cooking performance.
James