web analytics
Good day from South Oz - Forno Bravo Forum: The Wood-Fired Oven Community

Announcement

Collapse

Forum Issues Update

Things are progressing in getting things back in order on the Forum! User avatars should be showing up. Attachment and inline images are in the process of being uploaded. We are still looking for a migration path for the Photoplog gallery. Thank you for your patience!
See more
See less

Good day from South Oz

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

  • Good day from South Oz

    Hi, my name
    Last edited by wotavidone; 03-31-2013, 12:23 AM.

  • #2
    Re: Good day from South Oz

    hi
    the pot idea sound interesting but the idea of an 8 inch 200 mm door doesn't same with the 26 in oven hearth. I built a forno brick dome 42 inch which is great plenty of room for pizza and dishes to fit through the door. ive seen the oven at bunnings and it looked a little 'dinky' to small for both a fire and a pizza. Try for something about 32 to 36 inches maybe. sorry not a home at the moment uther would figure out the door size for these and yes consider a sqaure door shape you can fit bigger dishes in.
    Hebel can be an exceptable base insulation but being cement will break down over time in higher temps think of protecting it from heat with fb board or pealite layer on top. Yes I have Hebel as heath insulation in my oven no probs to date
    The thinnes of the pot will not give you a good enough amount of thermal; mass to an oven. Pherrhaps use the pot as a base for covering of 1/2 brick commons and home brew heat mortar.
    Again insulate the dome you got the mass you need now to keep the heat from escaping insulate the cheapest is probaly pearlite cement. dont be tempted to use house insulation unless you protect it from the hot bricks first so you may as well just use pealite
    keep up a progresss report
    this sound interesting sorry don't no much about pots

    regards cobblerdave
    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: Good day from South Oz

      Hi Mick,
      Read Russell Javons' book, "Your brick oven, building it & baking in it",
      ISBN 1 904943 25 X.
      He has build numerous brick ovens and uses 2 of them commercially in his wood fired oven pizza restaurant down at Willunga. He uses only common red bricks for the dome and 2 layers orn2" fired clay pavers for the hearth,msee for an indepth look:

      http://www.fornobravo.com/forum/f27/...alia-1930.html

      cheers.

      Neill
      Prevention is better than cure, - do it right the first time!

      The more I learn, the more I realise how little I know


      Neillís Pompeiii #1
      http://www.fornobravo.com/forum/f8/n...-1-a-2005.html
      Neillís kitchen underway
      http://www.fornobravo.com/forum/f35/...rway-4591.html

      Comment


      • #4
        Re: Good day from South Oz

        Dear Mick
        Sorry about the quality of that last post, did it on an I Phone waiting around a hospital...don't worry everythings alright and It gave me something to do.

        Pearlite... is like syrofoam beads light and full of air exept there volcanic rock
        the cement is only used to hold them together till there covered by someother layer. So when the cement burns away it doesn't matter. Yes my oven has a Hebel layer under the hearth but if you go this way at least give it protection of a layer of pearlite on top

        That pot price is a bit hexy you could buy a lot of brick commons for that. Cutting the hole would be a little nerve racking. If you find youself using one first experiment on a small cheap pot first. A square entrance would be better ..straight unfancy cuts. Mark out the entrance on the pot then drill largist hole in the corners ( not a hammerdrill ). Then use an angle grinder to cut up to the holes Not past them. the round corners will make it less likely to crack.

        Why increase your thermal mass with fire proof cement? Why not use clay on the outside. The pots clay as well so less chance of cracking due to 2 different materials reacting differntly with heat. Checkout the local road cuttings when you see a layer that is below the topsoil take some home smash it down with a hammer soak overnight. Roll in into a finger size piece and bend it backwards over itself over your finger. if it breaks straight away...no good . If it bends most of the way and doesn't break great you found the right stuff. No I havent built an oven of clay I have made bricks for a house from it though. The mass of the oven can still be covered in pearlite and finally cement rendered to protect from the elements.

        Its a great idea your making a steel stand as any failures can be scapped off and buried in the garden away from the brides prying eyes...

        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: Good day from South Oz

          Dear Mick

          Going brick great! whats with SA and pavers? Go commons (not House bricks full of holes)
          If you havn't got a set of formo plans go to the forno shop and download a set for FREE. its all in there the bloody things massive and its all in there bricks, Mortar mixes, the lot

          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


          • #6
            Re: Good day from South Oz

            hi Mick,
            If you use clay to clad the terra-cotta dome it will crack as it dries and shrinks, which is not a major problem because it is just adding thermal mass not strength. I think you would be better to use standard concrete 3:1:1 agg. sand, cement with half the quantity of cement replaced with lime. This can be reinforced with fibres, but do't use the plastic ones, they'll melt. Also don't use normal fiberglass as it reacts with the cement. You need a special alkaline resistant fiberglass for concrete.If the cement in this layer fails then the lime takes over just like the poor mans mortar.
            I agree with everything else you posted. but I can't see drilling a hole through that ceramic pot without using a hammer drill, you'll be there for three weeks. An angle grinder with a diamond blade is my first choice.
            Kindled with zeal and fired with passion.

            Comment


            • #7
              Re: Good day from South Oz

              "An observation I've made on my own, which I have not directly come across yet while reading the forum - fire bricks while not doubt being more robust than clay pavers, are nowhere near as heavy size for size - at least not the ones I've been handling "

              Maybe you are looking at insulating firebricks which are full of air and way lighter than a solid red. My firebricks are a little less dense than a solid red,because they are less vitrified, but you have to measure their density to tell. Insulating firebricks are not what you need for the inner parts of the oven.
              Kindled with zeal and fired with passion.

              Comment


              • #8
                Re: Good day from South Oz

                The materials used for dense and insulating firebricks are the same, but sawdust is mixed with the clay for the insulating bricks. The sawdust burns away leaving lots of good insulating air pockets. This fairly dramatically reduces the strength of the brick
                Last edited by david s; 06-04-2011, 11:39 PM.
                Kindled with zeal and fired with passion.

                Comment


                • #9
                  Re: Good day from South Oz

                  Dear Mick
                  The ideas are running thick and fast now. I just want to revisite a point that made earlier by DavidS it doesn't matter if the thermal mass layer cracks at all because it has your pot supporting it and that pot basically a dome. And if that cracks its still strong because the weight of itself and any other thing on it keeps it together. A dome is basically self supporting. Most ovens have a crack in them anyway but don't fall down and still cook the same.
                  Pearlite you can get it from hydroponic suppliers check the web and get some sent to you. The stuff full of air so it weighs nothing.... think of a bean bag full of strofoam beds and you'll get the picture. The local bloke sells a 100 Ltr bag for $36. ( a ltr is 10cm2) so you got about 1m2 to play with.
                  Interesting mix with the lime replacing 1/2 the cement.. they used lime in old brick chimneys cause it don't burn away like portland cement. Id use this myself and chicken wire as the remaining cement content will prevent the wire from rusting.
                  If its pavers you got its pavers you use dont worry about the round corners they will fill up with ash anyway I would recommend however lay them in a herringbone pattern so you oven tools don't catch on any stray edge.
                  With drilling holes in clay pots I should have explained myself better. I have drilled more drainage holes in most of the pots we have as they only come with 1 in the middle I use a masonary drill not in the hammer mode though other wise they break. Yep I'm afraid it slow... but safe


                  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


                  • #10
                    Re: Good day from South Oz

                    Lime in the outside render/stucco for an igloo style is also good because it has some elasticity, which is helpful with the heat wanting to expand things. I use a 4:1:1 sand, cement, lime mix about 15mm thick.
                    Kindled with zeal and fired with passion.

                    Comment


                    • #11
                      Re: Good day from South Oz

                      Mick,
                      One little problem that could cause trouble is that a large clay pot will probably have a flat bottom. If this area creates cracks then those pieces won't be self supporting and could fall off the roof of the dome.
                      There is little difference in price and insulating value between Perlite and vermiculite. Perlite is a slightly better insulator, but for me is slightly more expensive. although they are light materials they still cost ally in freight because they are high in volume. I prefer to use vermiculite because it has less fine dust which is annoying.They are both used in the hydroponic and nursery trade.
                      Brickies lime is what you want.
                      Dave
                      Kindled with zeal and fired with passion.

                      Comment


                      • #12
                        Re: Good day from South Oz

                        Mick
                        Just a quick though you seen the precast primavera ovens right....made in pieces for transporting. You talked early that you knew a local that had cast an oven....what did he use? is it avaliable local? is it a heatproof casting material.
                        From what I've read to cast an oven...styro-foam fruit box upside down. mold of damp sand over the top ,shape to suit, cover with thin plastic sheet (cheap plastic painting sheet) to stop sand from sticking. First thin layer of fire proof castable on. Use stainless steel wire (old welding wire) cut to lenghts thickness of castable req and poak into first layer so they give an idea of the thickness. More castable untill the ends of wire disapear. cut out entrance? make on precst entrance? whatever. when castable starts to go off reach the entrance remove first bit of sand and uncover the upturned box.
                        Break the box and remaining sand falls down and is removed with plastic sheet.
                        Should produce a shell of even thickness ready for insulating... if you can get some fire proof castable cement that is...
                        Regards
                        Cobblerdave
                        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


                        • #13
                          Re: Good day from South Oz

                          If you use the correct amount of water added to the castable mix there will not be any shrinkage, unlike a clay, cob oven which shrinks substantially, so you can simply cover it for 24 hrs and it's cured, then remove the sand, unlike standard concrete it does not need extended wet curing.
                          Kindled with zeal and fired with passion.

                          Comment


                          • #14
                            Re: Good day from South Oz

                            DavidS
                            Do you think this method would work? Sorry I know only a little of this and have not investigated it at great depth. I mainly posted to keep the ideas flowing and open up all option....
                            By the way weres a link to your build? Id love to know how you built an oven in "the Nth" it was hard enough here in the Sth East

                            Regards Cobblerdave
                            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


                            • #15
                              Re: Good day from South Oz

                              Yes this method will definitely work. If casting a dome in one piece you will get some fine cracks because the dome heats up unevenly ie hotter atvthe top cooler at the base. Something's got to give because of the rapid heat up and resulting expansion. A multiple piece dome is better, but even with some fine cracks the dome won't collapse. I made my mobile oven dome in one piece because I thinkmit's less likelybto shake to bits on the road.I did not create a thread fo my build only bits and pieces. The nth is great fo oven building now because it's the dry season. The wet season is lousy.
                              Kindled with zeal and fired with passion.

                              Comment

                              Working...
                              X