42" Corner Pompeii in Coastal Virginia

[Denamontini]

Russell,

Thanks for the info. In the ratio, the first number 5-8 is the perlite, correct? And secondly, about how much am I looking for to buy? Just a ballpark figure, if I copied your technique.

Also, do you have your pipe secured at any other spot besides the anchor plate? Did you mortar bricks over top of it? It looks like you did not???

Thanks again!

[UtahBeehiver]

[UtahBeehiver]

You can get construction grade perlite at any masonry supplies store, not your big box store but where the pros go to get concrete blocks (CMUs) the perlite is used to insulate block buildings by dry pouring into the cells of the block. This is probably the least expensive source for you. You can do up to a 10 to 1 ratio but at this it is a little hard to work with. With a CaSi blanket underneath, 5-8 to 1 will work fine. Attached is a chart showing the various K values at different ratios.

Actually, double wall insulated SS pipe is quite a bit lighter than a masonry/brick chimney. I have a four foot section on my oven and have not had any problems in 7 years.

Patience, grasshopper, is the wisdom of the day.

[Denamontini]

Thanks for the info! I will prob touch base again when I’m ready for that part. Dang, I’m rethinking this super expensive super heavy stainless steel chimney system...

Ok, the bad news... I jumped the gun taking the form off of my outer arch, yanked on it too hard 25 times and I cracked all of my work!?!

The good news... I was able to rebuild it all and fix the stuff I hated about it! My bricks were too far outward and I had over estimated how much room I needed for the chimney. So listen up, newbies, DON’T remove the arch forms too early with a sawing-like motion!!!! (Yes, I had it shimmed for the drop down method of removal, but got impatient ...)

[CoastalPizza]

...We are using a ceramic insulation blanket. Will that work the same as rockwool batting? What was your perlcrete mix/recipe? How long did it take to set up?

I chose rockwool over ceramic blanket due to cost. I think the ceramic blanket is actually easier to work with and is a better insulator. Most folks use 1-2" of ceramic blanket while I ended up using about 3-4" of rockwool. Since the perlcrete isn't under any load, I went with a 1:5 mix (cementerlite by volume). I mixed the cement first, pre-wet the perlite (using a bucket with holes in the bottom), then mixed the two. About 5-6" is the maximum height you can apply when going up the side of the dome, otherwise it slumps. I did a layer a day so it took 3-4 days to get up the sides of my dome. The perlite I used is the same stuff you get at a garden center. Try to find a place that sells it in 2 cu. ft. bags - the small bags at the home stores is pricy. See post #9 in this link for a good description of mixing perlcrete: https://community.fornobravo.com/for...2-build?t=7155

I went back to your builds and looked at how everyone attached the chimney. Did you have additional bricks covering the anchor plate one it was attached? My husband is convinced that the chimney system is too big and too heavy. Any thoughts? (it is 8" insulated, 36" tall stainless steel) Did anyone secure it beyond the anchor plate?

I went with a clay flue liner covered in 1.5" of perlcrete and then covered in stucco to match my dome.

[Denamontini]

What is the exact kind vermiculite/perlite that I need for over the ceramic blanket? It is not the garden variety, right? Can someone show me a pic of what they used and where they got it? I am very unsure of this part.

[Denamontini]

I also wanted to keep the dome shape so went with a stucco render coat followed by Seal-Crete waterproofing. If you isolate the outer dome from the inner oven with some sort of soft(ish) insulation, the inevitable thermal expansion of the oven's core is transmitted less to the stucco render. I went with about 3-4" of rockwool batting followed by 2-3" of perlcrete to act as a base for the stucco. Also, I used Quikwall rather than regular stucco for the base coat over the perlcrete since it is reinforced and fairly waterproof. I tinted the stucco finish coat with Ironoxx pigment. Since curing, I've done three full 900°F plus firings for pizza and no cracks so far.

Sorry for the delay! Thanks so much for the information! We are using a ceramic insulation blanket. Will that work the same as rockwool batting? What was your perlcrete mix/recipe? How long did it take to set up?

I went back to your builds and looked at how everyone attached the chimney. Did you have additional bricks covering the anchor plate one it was attached? My husband is convinced that the chimney system is too big and too heavy. Any thoughts? (it is 8" insulated, 36" tall stainless steel) Did anyone secure it beyond the anchor plate?

As always, THANKS for your time and wisdom!

Dena

[UtahBeehiver]

Congrats on plugging the dome. As far as curing, this is where a lot of builders get impatient and fire too hot, too fast. I would suggest you get the dome insulated before doing and firing, insulating the dome reduces the temperature difference between inside and outside the dome which reduces the chances of cracking your hard work. You could start some mild heating a halogen light, then briquettes for a few (you can cook some dutch oven stuff) then, then small kindling fires and so on. One extra log of the fire can really spike the temp. so again, be patient.

[Chach]

Great Job!

[CoastalPizza]

... We like the stucco look and we want to keep the oven looking like a dome. What’s best practice in using stucco or a stucco-like product? We live in a mild climate with plenty of rain and humidity. Any ideas?....

I also wanted to keep the dome shape so went with a stucco render coat followed by Seal-Crete waterproofing. If you isolate the outer dome from the inner oven with some sort of soft(ish) insulation, the inevitable thermal expansion of the oven's core is transmitted less to the stucco render. I went with about 3-4" of rockwool batting followed by 2-3" of perlcrete to act as a base for the stucco. Also, I used Quikwall rather than regular stucco for the base coat over the perlcrete since it is reinforced and fairly waterproof. I tinted the stucco finish coat with Ironoxx pigment. Since curing, I've done three full 900°F plus firings for pizza and no cracks so far.

[Denamontini]

Jewels of wisdom on the cure? How long do we let it sit before the first mini fire?

Now I need the brain trust to give me a few ideas...
How shall we finish it? We like the stucco look and we want to keep the oven looking like a dome. What’s best practice in using stucco or a stucco-like product? We live in a mild climate with plenty of rain and humidity.
Any ideas? (Personally, I’d like to tile it with the tiny 1” mosaic tiles, but the Mr. seems to think that would take a long time.) My main concerns are creating a water proofish outer shell that will not crack.
Has anyone been successful without putting a roof on it?

Thanks again!
Dena

[SableSprings]

As everybody says...we all need closure. And for those of us going through a WFO build...it's really a great rush to put the final keystone plug(s) into the dome! Next, on wards and upwards to the outer arch & chimney. Looks like you'll be doing the cure and starting to experiment with baking well before summer. Keep up the great work Dena (and company)!

[Denamontini]

We did it!!!

[JRPizza]

As Russel has been known to say - "Mortar is your friend"

[SableSprings]

Yes, Dena, perfection has a place in the world...it's just not as interesting a place as where we all live. I totally understand the drive to make things perfect, but I think older and wiser heads would lean towards "it's just a pizza oven...THAT WORKS!"

I've posted these pics before of an oven in Sorrento Italy that I got to use for a week. (I suspect it had been years since it was fired up and probably my fingerprints are the last ones on it...) Note the door in the second picture...rusted out along the outer rim. The oven was built into a hillside and I'm absolutely sure it had only dirt for insulation. When we arrived there was a large amount of dried grape (big, old trunk pieces) and olive wood. I had to clean out the oven area so I could work there and thought I'd need one or two fires to dry the oven...wrong! I struggled to get the oven up to pizza temps, sorta made it for short periods of time...but the heat sink of the hillside dirt really took away the bite of the fire from the bricks. I did manage to make several batches of bread, but at really low temps...barely seemed browned to me (but soak anything in olive oil or tomato sauce while you're in Italy and you can choke it down with a big smile ).

The only reason I'm yakking about this, is that whenever I see someone's oven that's better looking than mine and start thinking I should have done a better job, I simply recall my Sorrento experience where everyone there only focused on (and remembered) what came out of the oven--not the oven build quality. Soon you'll close, cure, put on a no doubt fabulous looking outer enclosure, and get on to the good part of using the beast. Don't beat yourself up over the things that make your oven uniquely yours.