SS Flue Design Styles, Chimneys and Finish Discuss SS Flue in the Pizza Oven Design and Installation forums; Hello all - I had posted this in my Brick Oven Photos thread but didn't get any feedback, so I ...

[leemc]

Hello all - I had posted this in my Brick Oven Photos thread but didn't get any feedback, so I thought I would post it here also. I plan a chimney mounted center dome with the vent in the traditional front location. You can read more about that in this thread.

http://www.fornobravo.com/forum/f9/t...mney-5809.html (Thoughts on a Centered Chimney)

I have a quick question. I had planned on doing a clay liner all the way from the vent, across the dome and up the chimney. Since I am having to keep the transition flue in the insulated space between the inner and outer dome, I would like to keep it as thin as possible without messing up my draft. I was thinking something like a 6"X10" but when I look at the clay liners that is not one of the standard sizes - I would probably have to buy a larger size and cut it to narrow it. As I searched I found this product which looks like it would work well for me since it can be ordered thin and wide, is thinner walled than ceramic, is flexible and I can get in a 6"x11.35" size.

Oval chimney liner, stainless steel oval chimney liners, oval flue liner

Has anyone used this product here? I was worried about stainless steel - will that last pretty much forever in a humid environment like Florida's? Also will the fact that it is corrugated be a problem with the draft or keeping clean?

Thanks

Lee

[glennb]

The SS flue should be ok, however it may show signs of surface rust if there is enough moisture in the air, particularly under the soot. Realistically, there is nothing better in the steel flues, and it will still last 10-20 years at least I would imagine.

[asudavew]

I'm sure Dmun will let you know.
He's the man when it comes to flu liners!

[dmun]

I'm sure Dmun will let you know.
He's the man when it comes to flu liners!

I'm afraid I don't know how the oval flex flue liner is going to work for you. I mostly don't understand your plan. Are you planning to support your centered flue above your oven, and run the oval flue liner in the side? It's hard to comment on something I don't understand. Perhaps a sketch?

[leemc]

Hey Dmun

Hopefully the attached drawing helps. The oven is a 36" igloo with brick outer shell. Basically this is a section cut through the center of the oven. I just think the center chimney looks much more natural and symmetrical, but it complicates things quite a bit.

Lee

[james]

I have looked at the flexible stainless chimney pipe in the past, but I have never used it. My memory is that it is pretty expensive, so the times I have wanted to angle back over the oven, I ended up using straight lengths and angle offsets.

I would also make sure the pipe is rated to the very high temperatures it is going to see right above the vent. That said, it would be easy to wrap back over the dome, and then straight up in the center of the dome.

Keep us in the loop and let us know what you decide -- and how it works out.
James

[dmun]

That flex liner is made for lining obsolete or unlined older chimneys, it may not be rated for direct flame contact, like you get when you build the big fires in a brick oven. It also has no particular compressive strength, and it looks like you are putting the heavy flue tile right on top of the squishy flex tube.

Here's what I'd do to make this plan work: I'd make the transition above the door out of firebrick, with a flue liner shaped hole in the back. I'd make a flue tile sized flat on the top of your dome with refractory mortar, and put a piece of your two inch thick refractory board insulation on top. This would give support to your run of flue tile. I'd cut a flue liner shaped hole in the bottom of your first piece of flue tile(easier said than done), and have the flex run just between the two, with the spaces around it filled with vermiculite concrete or whatever.

Some Naples style low dome ovens have the vent built right on top of the brick dome with whatever passes for firebrick splits (thin bricks) in Europe. The flue is supported by the structure of the dome. That leaves an important stripe of your dome uninsulated
which is less of a problem when you have a fire-in-the-oven pizza bake, because that part of the dome is heated by exiting flue gases. It leaves a cooling flow of air next to the top of your dome when you are trying to do retained heat baking: It may limit the ability to cook things like turkeys which need hours of heat.

The other problem with this semi squirrel-tail plan is that your nearly horizontal flue run won't comply with the 2 30-degree angle allowance in building code, if you are running this past an inspector.

[leemc]

Thanks for the advice. I think I am going to skip the flexible flue liner and try to fashion something out of thin brick, refractory mortar and modified ceramic flue liners. I will post pictures of this contraption as I progress and let you all know how it works out.