No announcement yet.

Metal dome: what thermal mass to use?

  • Filter
  • Time
  • Show
Clear All
new posts

  • Metal dome: what thermal mass to use?


    I've done some research and read through many pages of posts on the forum. I'm not the handiest with brickwork, and was hoping to use a metal half-sphere as the interior dome structure for the simplicitiness and "fool-proof" aspect, then lay my thermal mass on top of it. I know some have posted that this is what they have - my question is: is this format able to transfer the heat as necessary to cook a pizza fairly adequately (like a 2-3 minute pizza)? Or does the metal make it difficult to really transfer the heat back from the thermal mass to the pizza? My main use of the WFO is for pizzas/immediate cooking, but it would be nice to have at least some secondary ability to cook something for another 3-4 hours with a slow roast after the fire goes out.

    I have a few sketches attached. Any feedback from the veterans on what thickness steel to go for, and what thickness/layering of thermal mass to use? Do I cut fire bricks into 2 or 3 pieces and lay those directly on the metal sphere as much as possible, and fill in with the refractory mortar (because the fire bricks are a better thermal mass than the refractory mortar)? Or do a base of refractory mortar (say, 1" thick), then set the fire bricks slightly into that?

    For the interior metal dome, I know that there is a benefit to having a spherical shape to facilitate the heat distributing evenly...but I know you also want a thin metal shell for this concept. Is it possible to use something like a 30" diameter wok like this for the interior dome?

    The wok is 16 gauge carbon steel, with a 30" diameter and 9" depth. Would you have concerns about this 9" depth might not allow the heat to circulate? Or would the thin 16 gauge allow enough heat to transfer from the thermal mass to cook the contents in the oven?

    Thanks for your collective wisdom!

  • #2
    I probably donít know enough to make an accurate comment but I suspect the steel will expand and contract too much and will fail over time.
    i think the repetitive hight temp in the top of the dome will break down even stainless steel?
    The more standard way of building over a form made from damp sand might work better for you but I can see the appeal of your idea.
    Last edited by fox; 08-20-2018, 10:16 AM.