Cement ? Newbie Forum Discuss Cement ? in the Good Background Information forums; Ok I searched an did not see an answer for this. Can cement be used too make a clay like ...

[johnism]

Ok I searched an did not see an answer for this.
Can cement be used too make a clay like style oven or maybe even using a large drain pipe cut off ?
Would one reason be because of the insulation or can a certain cement mixed with perlight(sp) be used .
Thanks for the info and educating the newbie,
john

[dmun]

Ordinary concretes, made with portland cement, sand, and gravel, do not withstand the heat of an oven. They will crack and break apart.

Whatever you make your oven from, brick, castible refractory, clay, you will need insulation completely surrounding the oven. This is where the perlite (or vermiculite) concrete comes in. It's never in direct contact with flames or oven heat.

[johnism]

Cool that answers the cement one.. I see that you can purchase clay flu pipe in 36 Dia and was thinking that could be cut in half and used as a dome and then insulate it after the fact.
Any thoughts?

[dmun]

I see that you can purchase clay flu pipe in 36 Dia

We'd sure like a link on that one! Who says there's nothing new in the world? Is it round or "square"?

I just did some googling to answer my own question. The reliable Superior Clay has round ones in 36. Remember, that's a flue tile, and probably not much more than an inch thick. You would probably want some additional mass to bring it up to the thickness of whatever you do on the ends (or the top, I don't know which orientation you're planning).

Just a couple of notes on flue tiles. We've heard repeated reports of them cracking. You probably don't want to fire it up until it's finished and insulated, to reduce thermal shock. Also, it can be cut with a diamond blade in an angle grinder, but it's NOT a fun job. Wear lung, ear, and eye protection.

[timo]

Yes, the flue tile is very hard and heavy. It is loud on the ears when cutting and you don't want the orange dust in your lungs. Diamond blade in angle grinder will do it like dmun said.