is it possible to make the dome entirely of a concrete vermiculite mix?

[muckrunner]

is it possible to make the dome entirely of a concrete vermiculite mix?

i am a formwork carpenter and have formed up many different shapes and crazy designs for various things so im just wondering if i can make a pizza oven dome completly from some kind of concrete mix...

If not would it not be impossible to make a thin concrete/vermiculite outer shell and once cured simply lay bricks on the inside??? weight may be an issue but im after a way that can be built and transported...

cheers ben

[MK1]

Re: is it possible to make the dome entirely of a concrete vermiculite mix?

I think it would be more difficult to build the oven from the outside in.

Mark

[Mitchamus]

Re: is it possible to make the dome entirely of a concrete vermiculite mix?

Hi Ben,

You'd be much better off to use refractory mortar/concrete than vermi-crete

If you wanted to go down the cast route, most people make forms out of sand.

hope this helps,

cheers,
Mitch.

[pacoast]

Re: is it possible to make the dome entirely of a concrete vermiculite mix?

Just to clarify, it would probably be easier to cast the inner dome. It would be hard to lay bricks on the inside of a hard shell. But in this situation, you don't want to use an insulating product like vermicular concrete. You'd use a castable refractory such as Mizzou Plus (or the equivalent brand available to you locally). Something that has similar thermal properties to firebrick.

Ideally you'd want to cast it in several sections so that thermal expansion has less tendency to crack & pull apart the dome. Then mortar those sections together. That's not to say that you can't cast it in one piece if you really want to. Others have. A good starting point would be to search for and read the experiences of others on this forum who have already gone that route.

Once your castable dome has set, then you could insulate it with any number of products including vermicular concrete on top of the inner dome that you cast first.

You cannot make the entire dome from vermicular concrete. Well, you could. But it wouldn't work very well. The inside dome needs to hold and radiate heat for the oven to work properly. But it is possible to cast a shell within a shell and not use firebricks at all if you want to.

.