Planning my 32" cast oven

[AndreasP]

It takes me about 2 - 2 1/2 hrs to heat up and have the dome completely cleared. I find that waiting another half hour hour or so makes for easier pizza baking and a more consistent heat. So typically I start 3 hrs before I want to make pizza.

As far as heat retention, I have an insulated door, but it doesn't have a gasket, so I think there may be some heat loss around the edges.
The temperature I get depends a lot on how hot the oven was when I started. It takes a lot of wood to keep the oven at 900F, and we often do desert pizza when we are done with the normal pizza.
I find that after 12 hrs. I am around 450 or so, a bit too cold for baking baguette. But not too difficult to heat it up again if I need to.
I am sure I could also improve the temperature by making another large fire when I am done with pizza, but then again, I might just as well make a fire the next day.
It would be nice to have the oven at 550 after 15 hrs or so, what would allow me to get up in the morning, finish the bread and bake it in the oven around noon).

Attached is a graph from 4 different firings. Of course the graphs are a bit offset based on the starting temp, but they provide a good idea of what is going on. I simply fit an exponential decay to the points.

[evo]

hey could you share please how long it takes to heat it up and how long it retains the heat for?

[UtahBeehiver]

Most autoparts store carry breather caps. You can use a 1/2" pvc bushing with 1/2" mpt plastic breather valve. See Gulfs build.

[AndreasP]

I bought it at Grainger, it's the only place I found a screw in vent. 3/4 I'm NPT, so it fits a copper screw fitting.
I feel it's a bit big so I'm looking for something smaller.

Maybe just close it up completely, since the vermicrete is exposed around the chimney below the flashing at the bottom.
Then again, probably not a ad idea to have an opening on the tallest point of the dome.

[gnwjr]

Excellent! It’s looking like I’ll be using your waterproofing technique as well. Do you have a source for the breather vents?

Thanks

[AndreasP]

gnwjr
We had some unexpected rain last week. 0.22 inches overnight, so actual rain, not just a sprinkle.
Made pizza yesterday and the oven worked just fine. Didn't notice a difference, so for now I think the waterproofing is working.

[gnwjr]

Ok, thanks. If you come across anything, please let me know.

[AndreasP]

Glen,
Not sure how to judge the effectiveness of the Red Guard.
It went on really easy and seems to be quite durable. A nice thick rubbery layer. I used 2 coats.

From the way it looked after I had applied it I think it will do the job of keeping water out very well.
I hope that the Red Guard together with the flashing I placed and sealed around the bottom as well as the tiles below the insulation will keep the oven from getting wet.

It doesn't rain much where I am, so it will probably not be until next fall that I find out if it is really waterproof.

[UtahBeehiver]

IMHO, I would not cure until you have the insulation on the dome but before you stucco. Insulating the dome reduces the temperature differential between the inside and outside of the dome during the cure thus reducing the potential of thermal shock cracking.

[gnwjr]

Very good looking pizza oven, my congratulations on the completion.

I’m getting close to completing the dome on mine, another 5-6 rows, then the curing fires. I’ll do those before 3 inches of ceramic insulation followed by a rendering stucco scratch coat and a brown coat. All that to ask about what results you’ve seen regarding the RedGuard? I’ve been thinking the same thing, but there seems to be a lack of information.

Take care and again thanks,
Glen

[MarkJerling]

Andreas, that looks so nice. Time for me to start shopping for mosaics! LOL

[AndreasP]

Thanks, yes, it took a lot of time and effort.
Luckily the back is against the wall, so you basically can't see it unless you climb up onto the counter and lean over.

The biggest challenge was that three was only about an inch between the oven and the back wall.

I just took a sheet, slid it down and tried to push it against the oven with a stick.
Same for the grout. Tried to squeeze it in with my hand, then a stick and scrape most of it off.

Here is a photo from as far from the back as you can see it.

[Kvanbael]

That is a beautiful penny tile finish! Wow! That must have been very unforegiving for irregularities. Curious to see how it aligns towards the back.

[AndreasP]

Thanks, if I did it again I would pay even more attention to the surface of the dome and make sure it's really smooth without any ridges or dips. It'll make tiling a bit easier.

Also, cutting the sheets into strips really helped.

Initially I tried using a while sheet for the bottom, then strips if three tiles wide, but i had to take them off again to go single tile strip. It's just too easy to see the seams.

[MarkJerling]

That looks really nice. I keep thinking I'd like to mosaic mine.