Perlite equal to Vermiculite?

[Derkp]

Can I interchange perlite with vermiculite in oven applications?

Does Perlite work as well for the insulation slab under the firebricks?

Any tricks for mixing with concrete?
Thanks

[Neil2]

"Can I interchange perlite with vermiculite in oven applications?"

Yes. Go for the "course" grained perlite.

[kebwi]

Mix perlite more gently than you would vermiculite. It is prone to breaking down to smaller and smaller particles during mixing. Other than that, they're basically equivalent.

[dmun]

I used perlite and like the fact that the white color lets you know when it's fully mixed with the portland. But yes, they both work. You can either mix the dry ingredients and carefully trowel in the water, or mix the water and portland into a slurry and mix in the light stuff. This technique needs a mixing paddle in a power drill to mix the slurry.

[Derkp]

Great! We have already bought 3- 4cu/ft bags, hoping it would work.

How thick of layer do you think would be appropriate for a oven floor of 4 1/2 firebrick, the brick are 4 1/2 X 3-6 in X18 long, and overall oven dimensions (inside) of 28 X 36?

Thanks,

Derk

[Neil2]

four inches

[Mitchamus]

If you're mixing in a wheel barrow - add the water slowly.

If you just dump half a bucket of water in - the Perlite will fly out of the barrow and go everywhere!!

(don't ask me how I know...)

[Neil2]

Mix gently. Try to avoid breaking down the perlite particles.