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How to fix these problems

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  • How to fix these problems

    Greetings. It is getting warmer here on the East Coast. I pulled the tarp off my almost finished oven and am starting a slow warming process.

    I finished the oven itself, but the chimney area was rushed because of the approaching cold weather. We are all very inexperienced, and it was a team effort. Three obvious problems came up with our chimney build.

    1. As you can see from the first photo, the outer arch is very high and large. My limited experience with firing the oven so far suggests that there is a vast amount of heat loss out the front. There is some smoke, but not an overwhelming amount.

    Should I build a second arch below the first to make the outside entrance lower, thereby enclosing more of the chimney area? Most of the ovens I've seen have a relatively low outside opening, though it does tend to be wider than the inside one.

    2. Secondly, I tried in my inexpert way to build some kind of insulation into the break between the chimney area and the oven. Unfortunately I used bricks but out of cal-sil board, and now they are flaking into the oven entry. I assume I need to remove them, or cover them up in some way to prevent flakes from getting into my baked goods.

    What would you suggest?

    3. Last, my chimney seems a bit small for the oven (inside dimensions are 36" x 48"), and I'm wondering if that is why I'm getting smoke out the front. The ceramic flue is an 8 inch square one. I was thinking of adding another length to add area, or perhaps figuring out a way to put a stainless chimney on top of what I have. I will need some kind of cap too. Any suggestions about that problem?

    Given these three problems with the chimney area, perhaps you would recommend that I just cut off the top and start from scratch?

    Thanks in advance for your expert advice.

  • #2
    Re: How to fix these problems

    It appears that you have room to build an arch inside the existing, I would do that and it will probably take care of the smoking, too. For the flaking bricks, I would worry about it until it became a real problem, maybe parge it with refractory.


    • #3
      Re: How to fix these problems

      Originally posted by chickade View Post
      Unfortunately I used bricks but out of cal-sil board, and now they are flaking into the oven entry.
      I'm not sure I understand this. You cut cal-sil into blocks?
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      • #4
        Re: How to fix these problems

        Looking at that last picture, I wonder if you might be able to improve your draw by beveling the edge of the brick supporting your flue pipe to provide an easier transition for the smoke to flow upwards to the pipe. If you have a rotary saw with a diamond blade (e.g. Rotozip or Bosch makes one) or a disc grinder you should be able to do it without too much trouble. Remember it doesn't have to look too pretty because it will be difficult to see and it will get covered in soot anyway.

        If you decide to rebuild (unnecessary IMHO), here's a photograph of what I did by splitting a brick length wise on a diagonal and then putting the two halves together (rotating the top 180 degrees from the other). - Easy to do, almost impossible to describe.