pompeii oven construction began today

[aikitarik]

Awesome!

This is an inspiring series of photos. I'll have to start posting my own.

I've been working on pouring my foundation. It's a bit odd since I'm straddling the hearth across the top of a 3 foot retaining wall, but almost done.

Thanks for the detailed posts, they will be a help to me and others I'm sure.

Tarik

[Keith Oertli]

Paul, loks great! I would not worry about the 2.5" vs 3" brick thing. Your oven will perform as designed.

I am curious as to how easy it was to dismantle the foam board template?

Also, how many days did it take to build the dome using the template?

K.O.

[paulages]

the dome went up over the course of 3 days i think (not sure, but the dates are posted on the posting times with the photos). i'd say a good 8 hours at least, but the only thing that kept it from going really fast was figuring out how to cut the bricks for the header. i'm stubborn and so i wanted to go with the arch style header, just to do it, but i can see the advantage to using jim's angle iron header or a solid piece (refractory suppliers have solid cast header lintels sometimes).
as for removing the styrofoam---it took about five minutes, including sweeping to floor out. it really did make keeping the dome shape very easy.three quarters of the way up, the bricks just layed where they needed to go. however, i can also see the advantage to jim's freestanding method for the first several courses, allowing for easier cleaning of the inside as the walls go up. the styrofoam templates were jim's idea though (actually i used 1" styrofoam board, sold for coolers instead of the 2" rigid insulalation he suggested, as it was significantly cheaper), and it worked great.
i mostly regret the 3" bricks for asthetic reasons, but that won't matter too much when i get back and start using it. can't wait!

[david]

Beautiful job Paul.I'm looking forward to the vent /chimmney installment as this was the area that i'm stiill wondering about?Though i've built mine,i'm still uncertain as to a few things and plan on possibly changing the design for my next one!I have yet to add a semi-circular steel plate in the doorway.(Does this improve the draw/airflow?)I 'm not sure if this is the reason I am getting some smoke escape from the oven doorway,or if it is just due to natural external breezes?I'm concerned about the smoke issue as the next one I build will probably be an Interior oven(Any thoughts James?)The low dome Neapolitan ovens use a centered chimmney (or even a rear I believe?) so that all the heat from the oven is utilised as it escapes up the vent and runs over the dome.What are your interior H & W dimensios BTW?Can you please post a detailed series of photos of how you did the Cedar Shakes as this is my next project !Regards,David

[paulages]

david,
i'll give you a proper reponse when i get home in a few days. i"ll have to double check the height (17.5" i think), but the floor is 42" in diameter. the opening in 11.5" X 18".
what exactly do you want to know about the cedar shakes?

[david]

Just joking about the details with the shakes Paul!I do like how they look though and will get around to it one of these days...........

[paulages]

ha ha. okay, gotcha. thought you were making a joke about all of the previous detail, but you know how these subtleties tend to get lost in cyberspace....

[paulages]

okay measurements in...

the oven dome is 42" in diameter with a 17.5" height. the opening is 12" tall at the peak of the arch, 10" tall at the shoulders of the arch, and 18" wide. it seems to be drawing and venting quite well without the vent/chimney in place yet.

[paulages]

final settling...

so after all was said and done, the bricks found their way into the places they prefered to sit for the rest of their existence (hopefully), which resulted in some minor cracking here and there, and a slight shift of the arch, where the horizontal thrust of the top of the dome pushes against the arch, before the arch transfers that thrust downward. the next course of arch brick that sit in front of the current ones should help anchor everything and prevent it from ever moving farther, though it seems to have settled where it is.



i applied some pumpable "insawool" refractory insulation at all of the cracks, and plan to apply an entire coat of the same product in bucket form over the entire dome to help insulate. my refractory mortar layer around all of the bricks is relatively thin; i had planned to put one more coat over the entire thing in the end, but now i'm wondering if there's any point? now the bricks have settled, it doesn't seem like it would do much structurally, and the extra thermal mass would just mean longer heat-up time.

does anyone see this plan to leave it as is and just insulate next being a problem?

[james]

I vote leave it as is, as the dome seems robust. I can't think what another coat would do, and your mass is already good.

Is your isawool insulation wet, or a blanket? Are you going to use a blanket before your loose vermiculite?

I tend to think that a 1" blanket and 4" vermiculite really does the trick.

James

[paulages]

i just came from my supplier, and they gave me 5 70# bags of castable insulation (good up to 2500deg F) for free. they were left over from some old order, and the bonding agent begins to deteriorate if it's not used, so they can't sell it. i'll probably go back for more to use around my vent and chimney if it works well.

at that price, i might as well put it on really thick. vermiculite is cheap enough that i'll probably still backfill it loose in the end, but this stuff oughta do the trick.

right now, the top of the outside of the oven gets about 250 deg. when the inside is 800-900 deg, so i have to believe i'm losing quite a bit of heat that way. this will hopefully increase my ability to keep the oven pizza hot.

BTW marcel, they told me you had emailed them from my reference, which they thought was funny. let me know if you use them for the arch brick, and i'll see if i can help hook you up with the castable insulation.

[ColonelCorn76]

okay measurements in...

the oven dome is 42" in diameter with a 17.5" height. the opening is 12" tall at the peak of the arch, 10" tall at the shoulders of the arch, and 18" wide. it seems to be drawing and venting quite well without the vent/chimney in place yet.

I'll be interested in hearing of your cooking results. Those dimensions are more like the Neopolitan pizza ovens then the Tuscan bread ovens. Theoretically there should be an effect on the crust of your bread. I can't wait to see if the theory & the reality match.

Keep up the good work & keep on posting.

Jim

[paulages]

pizza results in...

jim, i've made fantastic pizza in it already, though i haven't ironed out the fuel situation yet. something i'm burning (i have a mix of fir, cedar, apricot, and madrone---i shoot for the hard wood after the coals are hot) is popping and shooting embers quite a bit when the fire is roaring, and the oven is too uninsulated to hold pizza temps unless it is alsolutely roaring.

i'll let you know how bread turns out.

[james]

You can have too much thermal mass, but I don't think there is such thing as too much insulation.

Can you get us any details on your castable insulation. For example, how does it compare with Vermiculite and/or a ceramic insulating blanket for efficiency.

James

[paulages]

yeah, the problem right now is NO insulation, but i figure i can't go wrong coating the hell out of the thing when the material is free.
i'm not sure how the material would compare with vermiculite insulation, but i'm fairly certain it should far exceed it's capabilities. this stuff is similar to the blankets, in that it's rated for extremely high temperatures (2500 deg. F --obviously far beyond anything i'll ever approach).

the product name is :Insulcast 25, made by Pryor Goggey Co. if anyone wants to google it.