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pompeii oven construction began today

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  • james
    replied
    I definitely think there should be a single set of core plans on www.fornobravo.com, that reflect the basic state-of-the-art. I can update the plan set on the net to reflect the internal foam forms, which I think is the best method.

    Right?

    James

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  • paulages
    replied
    Do you think there is enough content for its own Forum section?
    i don't know...maybe that's a question for everyone, or maybe for jim. perhaps there haven't been too many applicable posts yet, but i'm just thinking that in the future it might help someone wade through the different ideas and discussions if they are just shooting for jim's original plans.

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  • james
    replied
    Paul,

    I like the Advanced Pizza Oven concepts idea -- brick ovens for the hardcore builder. Let me think about how to do that. One idea would be to include all the real technical information there on arch design, insulation efficiency, concrete compression, etc. Issues that fall outside the range of the standard installation techniques. It could apply to both Forno Bravo refractory ovens and Pompeii ovens.

    Do you think there is enough content for its own Forum section?

    James

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  • paulages
    replied
    i coudn't find any product specs on the supplier's website, but the product you found is probably very similar. the 25 in the name denotes the temperature rating (2500 deg.).
    most refractory products are named this way, but with some the number refers to the alumina content.

    i would wager that any manufactured refractory product will outperform any anything you make yourself, but i believe much of the original point of the pompeii plans was to provide plans for an oven for which supplies can can be easily found.

    perhaps there could be an 'advanced building section' in the forum for posts like jim's arch specs, discussions about more professional products, and other techiques that go a bit beyond the 'possible for anyone' point.

    Leave a comment:


  • Alan
    replied
    First link from Google, though maybe not the same manufacturer because they don't list 70 lb bags:

    http://www.ablerefractory.com/datash...%2025%20LW.PDF

    THERMAL CONDUCTIVITY
    BTU/SQ.FT./HR./IN./oF

    Mean Temp. "K"
    400 F 1.91
    800 F 2.10
    1200 F 2.46
    1600 F 2.97
    2000 F ` 3.31

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  • paulages
    replied
    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.

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  • james
    replied
    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

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  • paulages
    replied
    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.

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  • ColonelCorn76
    replied
    Originally posted by 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.
    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

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  • paulages
    replied
    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.

    Leave a comment:


  • james
    replied
    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

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  • paulages
    replied
    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?
    Last edited by paulages; 08-10-2005, 09:12 PM.

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  • paulages
    replied
    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.

    Leave a comment:


  • paulages
    replied
    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....

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  • david
    replied
    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...........

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