Steel Dome Oven

[Frances]

...so far it looks just like everybody else's build......

Well, except my framing never looked that neat. Nice double form you've built there!

[berryst]

That thing is awsome. Should work very well.

[Wiley]

Thanks Berryst for the kind words.

Note to self in next life (and anyone else who might be interested): When making a form for pouring concrete that is a double form (pour one; inset 2nd form and pour it) pour all the concrete parts first. Pouring the slab and then pouring the vermicrete worked fine ...fine that is until I went to later pour the concrete surround. Oh, I did all the obvious things: stub rebar so the slabs would mechanically join and rough texture for same reason, but I didn't allow for the sponge characteristics of the vermicrete. When I went to pour the surround the vermicrete wanted to soak all the water out of the fresh concrete. Made it a pain to work and finish. Would have been alot easier to pour what would end up being a basin and then later pour the vermicrete into that.

Live and learn and forget by the time the lesson is needed again :-)
Wiley

[SpringJim]

soaking that vermic layer or using a layer of plastic could help too!

[Wiley]

SpringJim,
I tried soaking the vermicrete once the problem became obvious, and instantly realized the mistake in that as the vermicrete was a unit/mass only when dry and the cement holding it together was too new to actually hold anything together when wet again. When pouring the vermicrete a thin layer of cement rich water rises to the surface, as it dries/cures this thin layer of cement holds the surface together; sprinkling with water simply disolved that layer and made the vermicrete a loose mass of wet vermculite again. :-(

The whole problem would have been avoided by pouring all the concrete first and then the vermicrete.

As for plastic I would be wary of placing plastic anywhere that couldn't be removed. It may take a while for heat to get down to where it is in the structure and the fear of some point in the future having a pizza party and the oven ripping hot and all of a sudden the crinkled noses and the question, "What's that smell?" I've smelled plastic bags that have been blown under cars and caught by the catalytic coverter. Not a very nice smell and I would not be willing to take the chance in my WFO.

Wiley

[berryst]

I'm doing things a little different too. I'm using perlite. It does not absorb water at all as far as I can tell. I poured a 4" perlcrete insulation layer last night and today played with the first fire bricks . Yes, I did go to work a little bit late.

I'm sort of doing a cross between an igloo and a barrel. The operative word for me is barrel with tapered ends.

With the amount of steel you have it seems like you could just insulate the dome and skip the brick...just a thought Where did you get the dome?
berryst.

[berryst]

AAAAHHHH!!! End of propane tank....read the first post again!

[berryst]

did you get your crushed basalt at shine quary? Is it working yet? .....the basalt that is.

[Wiley]

G'Morning berryst, Yes, I purchased the 1/4 minus crushed basalt at Shine Quarry. Nice people to work with.

At present I am putting down my first layer of splits (1 1/4" thinckness firebricks). This is the surface that the dome itself will set upon. This is because I am concerned the expansion and contraction of the steel dome would other wise wear into the vermicrete over time. That would cause a separation between the steel dome and the basalt/fondu concrete and make for heating problems.

Upon the splits and only inside the dome itself will be a layer of full size (2 1/2") firebricks. This will make for a thicker bottom layer than is called for in the Pompeii Plans. That will increase the time needed to reach pizza temps, but on the plus side it should also increase the holding capacity once at temp.

Today is the Fourth and while my wife gets to go to Seattle and watch the fireworks at Gasworks Park with the kids and grandkids I get to stay home and watch the dogs and work on the WFO... Lucky Me :-)

Wiley

[berryst]

this is the same thickness I chose for my floor
I'd rather be here than gasworks any time!