Castable Oven Floor?

[phippsj]

I was wondering if anyone has thought about having castable oven floor? I thought it would have been pretty neat to be able to buy a 41" floor from FB, and then just build my dome around it. That way I get the satisfaction of the build plus a solid piece floor. However, I have also seen castable cement sold in various places that supposedly tolerate 2200 degrees. Perhaps add some crushed lavarock and then polish off the cast floor like the cement countertops? Is this feasible, or is my ignorance showing through?

Thanks!
-jared

[david s]

The material may be designed to withstand 2200 F but what it doesn't like is rapid heating and cooling. The resulting rapid expansion and contraction creates cracking.The larger the piece the more likely it is to crack. This doesn't really matter because a brick floor with many unmortared bricks is also a series of cracks but is free to expand and contract. Many commercial ovens have cast floors but are usually done in a few pieces to reduce the tendency to crack.

[dmun]

I'd avoid a castable refractory concrete floor, even if it wouldn't crack. It is, after all, concrete, and you're scraping your peels over it, no doubt scraping some loose. I'd stick with firebrick. It's cheap, and it works extremely well, as hundreds of ovens have shown.

If you want bigger pieces on the floor, you can get refractory tiles (really big firebricks) from a refractory supplier, but you pay a big premium over firebrick.

[drogers]

You could use soapstone.

[phippsj]

Originally Posted by dmun

I'd avoid a castable refractory concrete floor, even if it wouldn't crack. It is, after all, concrete, and you're scraping your peels over it, no doubt scraping some loose. I'd stick with firebrick. It's cheap, and it works extremely well, as hundreds of ovens have shown.

If you want bigger pieces on the floor, you can get refractory tiles (really big firebricks) from a refractory supplier, but you pay a big premium over firebrick.

I did use the firebrick, just finished that part today. I had thought about Soapstone, but was worried about the effects on bread. Like you say, tried and true.

[ggoose]

Though fire bricks are tried and true from a heating/cooling point of view, I am curious as to the effect of repeatedly scraping a metal peel over a brick containing aluminum...it seems that aluminum will wind up on the bottom of the crust, which is then eaten. Though the amount on each crust would be small, metals tend to accumulate in the body. Any thoughts? Perhaps a soapstone cap over the firebricks?

gene

[brickie in oz]

Sounds like one of them urban myffs where by you get Al symers from consuming Al uminium that is consumed from pots and pans that contain Al uminium.

Al being the symbol for Aluminium of course, which is probably where this miff originated. .

[david s]

The cement used is calcium aliminate, not the metal. Similarly there is a large content of alumina in fire bricks, but not aluminum. Or as you Americans like to abbreviate it, aluminum.

[ggoose]

The compound Alumina is Al2O3...the Al is aluminum for the abbreviation impaired Not rying to start a ruckus, just wondering...

gene

[david s]

It would be similar to ingesting some rust (iron oxide) you're not eating iron. I read somewhere that Alumina is the most abundant material on the planet, present in both soil and rock. I think it is quite safe in this form unlike the refined pure metal aluminum.