web analytics
Oven cast in sections - cure before mortaring? - Forno Bravo Forum: The Wood-Fired Oven Community

Announcement

Collapse

I'm Peter Reinhart! Ask Me Anything! Monday, February 15, 2016 7:00-8:00 pm EST

To kick off our AMA feature, we have invited author, chef and master bread maker and host of Pizza Quest, Peter Reinhart, to be our first host! Peter will be in the Forum on Monday, February 15th, from 7:00 - 8:00 pm EST. If you are unable to be online during the live session, you can post your questions in the sticky post. Peter will answer those questions during the live session on February 15th. You can view Peter's answers to your questions as well as what happened during the live session in the session thread.

Ask Me Anything New Forum Feature

You will notice a new forum at the top of the main page called, "Ask Me Anything". This forum will be used for live one hour "Ask Me Anything" (AMA) sessions hosted by people who are knowledgeable in different areas pertaining to wood fired ovens. How it works:
- Each AMA will have a "sticky" thread where the community can post questions they would like answered during the live session. This will allow everyone to participate even if you can't be online for the live session. These questions will not be answered by the host until the live AMA; if you need an answer quickly, you should post it in the appropriate Forum area for the community to respond.
- Another thread will be posted for the live AMA. Registered users who are logged in during the live session can interact with the host by asking questions and receiving responses.
- The live thread will remain in the AMA forum to view after the session.

We hope you enjoy this new feature! Please let us know if there is a topic that you'd like to have as an AMA and we'll look for a host!

Forno Bravo
See more
See less

Oven cast in sections - cure before mortaring?

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Oven cast in sections - cure before mortaring?

    Hi folks,

    I've cast my dome in 4 sections and it's been drying nicely for the past number of days in the sun. Having cast it in sections, I was able to expose the internal surface of the dome to the sun to help drying. I've used a ciment/fondu/grog/sand mixture for my casting. I cut up some polypropylene rope and added it to the mixture to serve as burnout fibres.

    It has a 26" interior diameter and wall thickness of 2.5 - 3".

    My question is this - should I light some or all of the curing/drying out fires before I mortar the sections together and before I add the insulation layers? It seems to me that it would be good to light at least some fires before mortarting the sections together as this would allow any moisture to escape more easily and reduce the risk of cracking?
    My oven on a pallet build thread

  • #2
    Re: Oven cast in sections - cure before mortaring?

    G'day
    Cant see any problems mortaring it together? why would you not?
    If you using Pearle-crete as insulation you introducing moisture back in the build and your back to square one with the drying

    Regards Dave
    Measure twice
    Cut once
    Fit in position with largest hammer

    My Build
    http://www.fornobravo.com/forum/f51/...ild-14444.html
    My Door
    http://www.fornobravo.com/forum/f28/...ock-17190.html

    Comment


    • #3
      Re: Oven cast in sections - cure before mortaring?

      Originally posted by cobblerdave View Post
      G'day
      Cant see any problems mortaring it together? why would you not?
      If you using Pearle-crete as insulation you introducing moisture back in the build and your back to square one with the drying

      Regards Dave
      Thanks Dave,

      I thought the point of the burn-out fibres and going very slowly with the fires is that the difficult bit was getting the moisture out of the cast dome itself and giving it some time before mortaring it would allow some of this moisture to escape more easily. But it doesn't sound like it's much of an issue.

      In any case, the dome has had a week in the sun already so I guess it's time to mortar :-)
      My oven on a pallet build thread

      Comment


      • #4
        Re: Oven cast in sections - cure before mortaring?

        G'day
        You still have not said what insulation your using?
        If you use pearlcrete / v-Crete even over dry insulation it's still going to introduce water back into the structure. Its simple. The wet migrates to the dry.
        You can't change that. You can slow it down 1 inch of V-Crete at a time a week between each coat . Let the sun and the wind do it for you. Then a low and slow burn you don't have to crack your oven!
        Regards dave
        Measure twice
        Cut once
        Fit in position with largest hammer

        My Build
        http://www.fornobravo.com/forum/f51/...ild-14444.html
        My Door
        http://www.fornobravo.com/forum/f28/...ock-17190.html

        Comment


        • #5
          Re: Oven cast in sections - cure before mortaring?

          Originally posted by cobblerdave View Post
          G'day
          You still have not said what insulation your using?
          If you use pearlcrete / v-Crete even over dry insulation it's still going to introduce water back into the structure. Its simple. The wet migrates to the dry.
          You can't change that. You can slow it down 1 inch of V-Crete at a time a week between each coat . Let the sun and the wind do it for you. Then a low and slow burn you don't have to crack your oven!
          Regards dave
          Ah sorry - I'm using 1" of ceramic blanket, then chicken wire and a layer of vermicrete over that.

          Edit: I've just mortared the sections together. I've mortared generously over and around the joints. The Panyol 66 instructions say to mortar all around... do I need to do this? And if so, why is it necessary?
          Last edited by di11on; 06-09-2014, 04:53 AM.
          My oven on a pallet build thread

          Comment


          • #6
            Re: Oven cast in sections - cure before mortaring?

            It's to hold the thing together a bit more and fill in any gaps that heat can escape from.
            Kindled with zeal and fired with passion.

            Comment


            • #7
              Re: Oven cast in sections - cure before mortaring?

              Originally posted by david s View Post
              It's to hold the thing together a bit more and fill in any gaps that heat can escape from.
              Thanks David. She's all mortared up now. I'll let it dry for a few days and then put on the blanket and vermicrete outer layer.
              My oven on a pallet build thread

              Comment


              • #8
                Re: Oven cast in sections - cure before mortaring?

                Yes, I'm assuming you are doing an igloo in which case I think the best procedure, or at least that's the way I've found it best, is to insulate with blanket, then the vermicrete in layers of about 32 mm (inch and a half) and let each layer dry for a week, two should be plenty to get a nice even form. Then do some drying out fires (i don't like the term "curing" as it gets confusing with curing concrete or refractory when you are doing the opposite and trying to hold the moisture in).Then finally do your outer rendered shell. If you are doing a dog kennel style then you don't need to add wet vermicrete you can just fill the space with loose/dry perlite, vermiculite or fibreglass ceiling insulation.
                Kindled with zeal and fired with passion.

                Comment


                • #9
                  Re: Oven cast in sections - cure before mortaring?

                  Originally posted by david s View Post
                  Yes, I'm assuming you are doing an igloo in which case I think the best procedure, or at least that's the way I've found it best, is to insulate with blanket, then the vermicrete in layers of about 32 mm (inch and a half) and let each layer dry for a week, two should be plenty to get a nice even form. Then do some drying out fires (i don't like the term "curing" as it gets confusing with curing concrete or refractory when you are doing the opposite and trying to hold the moisture in).Then finally do your outer rendered shell. If you are doing a dog kennel style then you don't need to add wet vermicrete you can just fill the space with loose/dry perlite, vermiculite or fibreglass ceiling insulation.
                  Thanks Dave - appreciate that.

                  Thinking a little ahead, what mix do people generally use for the outer render?
                  My oven on a pallet build thread

                  Comment

                  Working...
                  X