The great thing is I've been able to get my feet wet with castable cement in the building of a backyard cook center for my mom. We've built a catenary arch kiln style oven with a small arched firebox in the bottom and a level cook top in the oven chamber. I'm pretty excited to finish the piece off this weekend. I'm going over there to build the final frames for the big catenary arch which is going to be the top, sides and back of the oven.
To build this thing we've used lincoln 60 fireclay, pine shavings, fine and course mulcoa grog, and Ciment Fondu which is a 40% alumina refractory cement. This was used in a 2,2,2,1 parts formula.
2 Fireclay
2 Pine Shavings
2 Grog
1 Ciment Fondu
We had to substitute some sand to complete the cook top because we were running out of aggregates at the time. We also had to substitute some Portland Type II cement into the cook top because we ran out of Ciment Fondu. So the top of the firebox itself has about 2 inches of good refractory cement, and the top of the firebox layer or cooktop has about 2 inches of Portland Cement. For this application it should be just fine, although I did have the idea that I would burn this thing to red/orange one time to cure it and I don't see that happening with Portland Cement. We'll see how it goes, but I certainly don't want to push the cook top the the point that it fails.
The tall arch we're about to build is going to be a 2" layer of medium density castable just like the firebox pieces were, followed by a 3 inch layer of light castable made with perlite. In the big arch we're going to put holes which will later hold spring mounted bolts for a flange which will hold the doors. There will be two doors on the oven one small one down below for the firebox and one up top for the oven which will be quite large.
