Round shape

[Dino_Pizza]

Re: Round shape

I would agree with everyone here. I know for SURE that 1 and half bricks deep and a tall "flu-box" suck the air up and out beautifully. Pizza_Bob just posted 2 good pics here of his vent and the brick angles at post 231:
http://www.fornobravo.com/forum/8/pi...d-7155-24.html

I'm actually (after looking at MY oven pic below) just a little over 1 brick deep but I've got a tall flu-box and like david said, having a funnel shape will greatly aid the draft.



I wish I would have followed more closely other builds to verify how shallow an entry you can go and not get smoke out the front. Maybe others have had good luck with less than a brick and tall funneling but I'm not sure.

I've also seen how others have used the rectangular clay pipe, cut at a diagonal and re-mortared to make a nice funnel shape that works.

-Dino

[Sharkey]

Re: Round shape

I think you could get away with less than a full brick, but I think a half brick might be too narrow. Anyway, you would need at least the same size as your flue.

In this photo of one of my early fires you can see exactly where the smoke goes. Most of it stays close to the back wall of the vent.

[GianniFocaccia]

Re: Round shape

Great shot, Sharkey. I think the curved slope to the sides of your vent work well with your hemispherical oven arch. Given this configuration, since the soot on the vent sides are an indicator of how far forward the smoke actually goes, a full brick depth appears to be more than adequate.

John

[Mike D]

Re: Round shape

Wow thanks for the help. Let me be more specific, I was thinking of having the whole entry one brick length deep (9"). The vent opening would be half that (4.5). The with would be as wide as I could make it. If you look at the modular ovens their entries as really short, the vents are not that deep,but are wide. I guess it would depend on how I do the flew to make the transition smooth.

-Kweb had a entry/vent I was thinking about. I don't know how to post one of his pictures.

Mike

[Lburou]

Our vent and heat brake.....

We just finished an oven entry inspired by Karangi Dude's entry. The flu opening is about 5 X 9, (entry is 11 inches deep), and it draws nicely. The clay flu is 8 inches on the outside and closer to 6 inside.



Was worried that our opening would not be up to the task, but the small fires I've done release a bit of smoke (15-25 mph wind at the time) on start only, then it draws well.

Mike, I want to encourage you that a modest sized flu will work well enough. The clay flu is cheap and easy in incorporate in to planning.

[Mike D]

Re: Round shape

Yes Karangi, that is what I was thinking. I need to figure out what/how I am going to use for the flew.

Mike

[Mike D]

Re: Round shape

As I am thinking about my vent, I think I need to pour a/the concrete counter around the oven first. The front of the arch/vent is not supported yet underneath. I think it should be solid below to give it a good foundation. As well as I think it will be easier to build the round brick enclosure on top of the counter, than build the round brick enclosure and then try to pour/build a counter to fit.

-I have never done a concrete counter before (as well as an oven), so I have been reading through the builds for advice. I have a few books (chang) and this is what I am thinking.

-2 1/2 thick counter with a continuous piece of rebar on the perimeter tied to wire grid 6x6". I was going to pour in place obviously because of the strange shape (and grind/polish a bit).

-How does this sound? I saw Nic the Landscapers mix advice http://www.fornobravo.com/forum/2/fi...d-15373-4.html and hope to use that as a guide. I was going to make a dark gray color with Iron oxide. How does one know how much to use?

Here are some picks with the surrounding area all cleaned up and a couple with what the bricks would do for the enclosure.

[brickie in oz]

Re: Round shape

and a couple with what the bricks would do for the enclosure.

If you knock the back of the bricks off with just a hammer you will end up with tighter joints on the front of the brickwork.

[Mike D]

Re: Round shape

Yea Brickie, I might end up doing just that depending on how it looks. But I will get there when I get there. I don't know if I like how a full brick looks in a round shape, if I cut them all in half I would get a rounder form.

-But I first need to do the counter and entry/vent.

Mike

[Mike D]

Re: Round shape

OK,

So I poured my counter around the oven and I finally finished the outer arch and the vent transition. I am in the process of cutting the ceramic flew pieces to fit on top of the arch (kind of like Less'). Here are a few pics.

I have to say that this outer arch/vent transition really make my brain hurt.

Mike

[lwood]

Re: Round shape

Nice job Mike.

[Mike D]

Re: Round shape

Ok- so it has been a wile sense my last post. I have been unable to get much farther in the build, but I did manage to put together the flue. This might have been the hardest thing so far. It took me all day to figure out the angles to cut that flue pipe to make the transition the way I wanted. I hope it works out.

- Here are a few Pictures of the flue and a unmortered look of the brick going on the outside (again, I know, I love to dry-fit everything)

I had a light inside the oven for a wile - with progressive watts to get the thing to slowly dry out. I have been reluctant to start any fires until I do the outer brick cylinder.

-Should I use a high temp mortar for where the red bricks connect to the arch?

-Anyone see any issues with this design?

Mike

[GianniFocaccia]

Re: Round shape

Great-looking entry, Mike! Your flue is quite impressive given the geometry and fit.

I'm wondering, though how much residual heat is going to conduct away from your oven through the entryway and into the brick enclosure. Will you be installing insulation where the entryway arch meets the brick enclosure?
John

[Mike D]

Re: Round shape

Thanks John,

I have been wondering the same thing about the heat transfer. But isn't that how all the oven work? You have to have some connection to the entry, right? I will be putting tons of insulating blanket over the dome and around the bottom part of the flue, but I don't know how one would make a heat gap around the outer arch.

Mike

[Aegis]

Re: Round shape

Thanks John,

I have been wondering the same thing about the heat transfer. But isn't that how all the oven work? You have to have some connection to the entry, right? I will be putting tons of insulating blanket over the dome and around the bottom part of the flue, but I don't know how one would make a heat gap around the outer arch.

Mike

Hi Mike,
I am at that same point for the outer arch and would love to make it thermaly isolated from the oven. How to do it without having the Pizza get insulation on it from the gap is the tricky part!
John