Movable not quite mobile cast oven

[jersey bob souvlaki]

I thought I owed you guys a look at what I did with the info I found here. This morning I took the forms out of the oven I cast yesterday. I have just one question about it now that if anyone could tell me I'd appreciate it. I'll call the refractory lady back tomorrow if I don't hear back here before then. I used the Mat 42 refractory cement from Mathios Refractories. When I bought it they advised me to heat the oven to 100C for 12 hours a day for 2 days to drive the water out. I just didn't ask if I should do that before or after I put the insulation. Doing it after seems counter-intuitive to me. Wouldn't think you'd want that moisture to go into the insulation. Anyway here it is.

[jersey bob souvlaki]

Up closer it doesn't look too bad to me. Structurally, I mean. Aesthetically I think it's kind of a monster. I see two cracks on the outside that I can't see from the inside. There was some crumbling at the transition from the dome to flue gallery and the sleeve for the flue pipe became dislodged when I removed the forms.

[fox]

I think the logic is that if you don't insulate then the dome will not obtain a very even heat and the areas directly hit by the flames will spot heat.

[david s]

It is a good idea to allow the casting to dry for a week before lighting any fires. Don't worry too much, most ovens have cracks. While the cast still contains moisture try filling the crack with some castable, but sieve it to remove the aggregate and mix it to a peanut butter consistency. Then leave the cast to dry for a further week, weather permitting, before insulating and lighting more fires.

The location of the crack is indicative of the top 1/3 of the dome drying and heating/expanding rapidly. The insulation will help even out the heat.

[jersey bob souvlaki]

Thanks for the replies, guys. But, david s, I'm a little confused by what you mean by a further week and more fires.

[david s]

I think you've dried the top half of the oven but it still contains water in the bottom half. If you fill the crack with more castable it will set in 24 hrs but it won't be dry. If you wait another week and let sun and wind remove more of the water it's much safer than firing. The oven is not completely dry until the whole of the inside surface turns white.

[jersey bob souvlaki]

Got her finished up today. Not a lot went according to my plan but I'm happy to report pizza with no explosions.
Thanks for all the help!