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Steady good heat without the large flames. How?

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  • #31
    Re: Steady good heat without the large flames. How?

    I don't. I figure the airflow is better sweeping around then straight in.

    Cyclonic is what I imagine..

    Chris

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    • #32
      Re: Steady good heat without the large flames. How?

      Originally posted by SCChris View Post
      I don't. I figure the airflow is better sweeping around then straight in.

      Cyclonic is what I imagine..

      Chris

      Got it. Thanks man. However that stiff is the same point i was trying to make, or ask, you are centralizing your heat mostly to that one side, then moving the heat over, or adding it over to the rest of the sides. So since you have your heat focused in that one area doesnt this stress the dome? Having one area 700F VS the other areas being 450F. For example.
      Matthew 19:26. With God all things are possible.

      My Build: http://www.fornobravo.com/forum/f21/...les-18741.html

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      • #33
        Re: Steady good heat without the large flames. How?

        I feel the heat stress problem is amplified by the presence of moisture in the oven structure. This isn't to say that differences can't be an issue but that where you have water holding the temperatures in one area down and a dry area where the temperature is free to rise you have a greater potential for stress cracks. If you have concerns about uneven heating, take your time to get to temp. Rather than 2 - 3 hours build a smaller fire and take 4 hours. Right now your oven is still in curing mode and it will continue to dry certainly through 10 solid burns and maybe more. Part of this breaking in period is also the drying of the supporting concrete slab and this drying doesn't relate to stress in the oven but it does relate to how long your oven holds the heat.

        On a separate note, are you related to the LA bread baking group? I see they are bringing a group member's oven live this weekend.

        Chris

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        • #34
          Re: Steady good heat without the large flames. How?

          V, relax, man.

          A fire raging off to the side is the same as one in the center. I thought SC gave some good advice and went with all the prior recommendations. That is, it will take a little time to bring the oven to even temps ( read: slow and steady) and move your fire around. 700*-900* is the same whether the fire starts in the middle or the side.

          Have a beer and cook something...you are ahead of me with the curing process.....I'm only two days in
          Old World Stone & Garden

          Current WFO build - Dry Stone Base & Gothic Vault

          When we build, let us think that we build for ever.
          John Ruskin

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          • #35
            Re: Steady good heat without the large flames. How?

            Thanks for the help guys, really appreciate the feed back, i was able to hit 700f today, but no too long, once it hit that mark i let it go down by itself, by not adding more wood, when it got to 700 i was up by the dome, and heard it crack some more, the cracks running from the bottom to 2/3 up. No smoke coming out, i feel like every firing or every 100f up the oven expand even more, which in return causes cracks.


            The next step is 800f , is 800 still considered curing? Or is that the scary fire? You guys speak of. As soon as im done curing ill insulate and stucco the dome.
            Matthew 19:26. With God all things are possible.

            My Build: http://www.fornobravo.com/forum/f21/...les-18741.html

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            • #36
              Re: Steady good heat without the large flames. How?

              I think at 800 you're there. Time at temperature is a plus, remember that just because the interior temp is X degrees the dome is far from saturated. My feeling is holding the temps for extended periods keeps the water moving out of the oven much better than going to temp and backing off.

              JMO

              Enjoy your oven!

              Sincerly

              Chris

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              • #37
                Re: Steady good heat without the large flames. How?

                Thanks Chris, im pretty sure the oven is dry, it was sitting under our Socal heat for a whole month before putting fire inside. But i will get to 800f and try to keep it longer. I hope the oven doesnt crack anymore.
                Matthew 19:26. With God all things are possible.

                My Build: http://www.fornobravo.com/forum/f21/...les-18741.html

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                • #38
                  Re: Steady good heat without the large flames. How?

                  Remember that cracks are to be expected even when you try to avoid them. At 800 most of your curing is finished and you can enjoy your first pizzas with friends.

                  Regarding curing as a point of reference, when I started looking into a WFO the methodology for curing was to build a small fire and get to temp and stop.. The following days increasing temps by 100F every fire until 800 or so and at this point the formal curing was finished. What I don't like about this method is that there is a lot more to the oven than the interior surface temp. It's my opinion that more effective curing can be done with less cracking if the oven can be brought to a temp and held at this temp for an extended time. I feel that these extended periods of controlled heating minimize the heat stress on the oven.

                  Ideally, in my mind, the heat during curing would build at a slow rate to expose the exterior side of the bricks to higher temps that facilitate drying. Substantially extending curing fires isn't fully realistic in most cases. The problem is the control of the heat source over the extended time.
                  • Firstly when you use wood to cure each branch is a bit different so the caloric content is different.
                  • Secondly the ability to focus on a fire and maintain a fire for extended periods is tough.
                  • Third the reaction of the oven to the heat changes, continually, throughout the curing.

                  Examples of the temperatures running well past the target are more than common because the oven becomes more dynamic, more alive, as it cures.

                  Enjoy your oven!!

                  Chris
                  Last edited by SCChris; 04-24-2013, 08:46 AM.

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                  • #39
                    Re: Steady good heat without the large flames. How?

                    Good info Chris thank you.
                    Matthew 19:26. With God all things are possible.

                    My Build: http://www.fornobravo.com/forum/f21/...les-18741.html

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                    • #40
                      Re: Steady good heat without the large flames. How?

                      Originally posted by SCChris View Post
                      Remember that cracks are to be expected even when you try to avoid them. At 800 most of your curing is finished and you can enjoy your first pizzas with friends.

                      Regarding curing as a point of reference, when I started looking into a WFO the methodology for curing was to build a small fire and get to temp and stop.. The following days increasing temps by 100F every fire until 800 or so and at this point the formal curing was finished. What I don't like about this method is that there is a lot more to the oven than the interior surface temp. It's my opinion that more effective curing can be done with less cracking if the oven can be brought to a temp and held at this temp for an extended time. I feel that these extended periods of controlled heating minimize the heat stress on the oven.

                      Ideally, in my mind, the heat during curing would build at a slow rate to expose the exterior side of the bricks to higher temps that facilitate drying. Substantially extending curing fires isn't fully realistic in most cases. The problem is the control of the heat source over the extended time.
                      • Firstly when you use wood to cure each branch is a bit different so the caloric content is different.
                      • Secondly the ability to focus on a fire and maintain a fire for extended periods is tough.
                      • Third the reaction of the oven to the heat changes, continually, throughout the curing.

                      Examples of the temperatures running well past the target are more than common because the oven becomes more dynamic, more alive, as it cures.

                      Enjoy your oven!!

                      Chris
                      I agree with you Chris. The recommended method for driving the water out of new kilns and castable refractory is a slow continual rise in temp. However the problem of doing this in a WFO is that if using wood fire the direct impingement particularly on the top of the dome creates uneven temperatures and to exacerbate this, as you mentioned previously, the water lower down holds the temperature back. Allowing the oven to cool down brings all the refractory back to the same temperature so the heating can begin again allowing the temperature difference to be much closer. There may also be some migration of water from the wet parts of the oven to the dry parts as the oven is allowed to cool, although in 24hrs I'd guess this would be fairly minimal. It could however be of an advantage if it were left longer, say two or three days between firings.trouble is at this stage you are so excited to get the oven dry and cooking, who can bear to wait more time.
                      Kindled with zeal and fired with passion.

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                      • #41
                        Re: Steady good heat without the large flames. How?

                        I did my last cure fire today, got up to 750-770F. Cracks appeared to have gotten wider, and now i can see through the crack at one area. I can see the fire ever so slightly, Structurally i guess it will be okay and i know it will still function as it should. My question is how do i repair it and what is the best way? Heat it up, have the cracks open up, grind out the cracks, widen the cracks and fill the cracks back in?. Now what do i use? Heatstop50? Rutland cement? Rutland gasket cement?. I have a bottle of the Rutland gasket cement which is good for 2000F, however i dont think that will be safe for food. I would really appreciate the help guys.


                        Here is the widest cracks



                        Here is the area of the largest crack going down to the floor.



                        Opposite side of the dome.



                        Matthew 19:26. With God all things are possible.

                        My Build: http://www.fornobravo.com/forum/f21/...les-18741.html

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                        • #42
                          Re: Steady good heat without the large flames. How?

                          And the crack where you can see through

                          Matthew 19:26. With God all things are possible.

                          My Build: http://www.fornobravo.com/forum/f21/...les-18741.html

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                          • #43
                            Re: Steady good heat without the large flames. How?

                            May i add that ive been heating it up gradually, not very slow but fairly slow, i had fire in there for about 4 hours.
                            Matthew 19:26. With God all things are possible.

                            My Build: http://www.fornobravo.com/forum/f21/...les-18741.html

                            Comment


                            • #44
                              Re: Steady good heat without the large flames. How?

                              V-wiz, have you insulated?
                              Here is where I'm headed.. Whatever you do to patch the cracks will not be structural or at least not very. I think I'd mix a small batch of render, just enough to fill these cracks. Insulate the dome with your blanketing start working on the finishing of the igloo or house. The insulation will not burn and it will stop these cracks from venting. The other thing it will do for you is to even out the dome temps and so minimize the stresses that promote cracking.

                              My opinion is that once you start curing above 250F there are advantages for loosely covering the dome with insulation. One of these advantages is promoting a more even heating of the dome and so minimizing cracking. This is my opinion and it's just theory... and you're far past 250F and your dome is ready to cook, so no matter what you need to insulate and weatherize..



                              Thanks

                              Chris
                              Last edited by SCChris; 04-30-2013, 08:36 AM.

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                              • #45
                                Re: Steady good heat without the large flames. How?

                                Thanks Chris, i will fix the cracks this weekend and insulate permanently, any special mortar i should use to fill the cracks?
                                Matthew 19:26. With God all things are possible.

                                My Build: http://www.fornobravo.com/forum/f21/...les-18741.html

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