flue and vent opening

[briot]

I'm trying to draw up plans for our oven I know this is a dumb question, but is the flue different than the vent opening between the two arches? If it is, how do they come together, how do they transition?

[Mitchamus]

Re: flue and vent opening

the easiest way to explain it is - have a look at the vent & chimney gallery...

there are some great pics in there that should explain everything...

The flue sits on top of the vent, they're not really the same thing.

On this site - a chimney and flue are talked about as the same thing, but a flue (by definition) is the area inside a chimney.

so to some up:
Vent - the hole in the oven where the smoke comes out
Flue - the passage created by the chimney that's moves the smoke away

In the following pics, the stainless tube is the flue (chimney).

this shows the vent:


This shows the 'vent transition'


This shows the flue (chimney) ready to be mortared


And this shows the flue (chimney) in place



Thanks go to RodneyF for the example pics - great job.

[briot]

Re: flue and vent opening

Thanks, that helps a lot.

[Annie Baker]

Re: flue and vent opening

Thank you VERY much for the explanations; I was very confused and now I feel more confident to go about building the front of my oven.

[leckig]

Re: flue and vent opening

how do you seal the gap between the metal flue and the bricks? Just a regular high temp mortar or something else?

[Mitchamus]

Re: flue and vent opening

the short answer (and in the example above) - Yes. (with brick work and mortar)

the long answer is - it depends upon what chimney you have purchased - some chimneys come with a 'base plate' (or adapter) which can be bolted to the vent transition using dyna-bolts or "Tap Cons" I think they are called in the US - either way they are masonry anchors.

you can see this in the pic below:

[leckig]

Re: flue and vent opening

Thanks but I should be more specific with my question, I posted it here:
http://www.fornobravo.com/forum/f9/a...html#post95816

[Tscarborough]

Re: flue and vent opening

I would mortar in firebrick around the flue with refractory cement at least one course, then give it a good coating all over.

[leckig]

Re: flue and vent opening

thanks! Good coating of what - the cement?

After much consideration I think I will scratch the idea of igloo finish and do the home enclosure, so I dont need to worry about the look of the flue, just need to make sure it stays where it should

[Dino_Pizza]

Re: flue and vent opening

Here's a pic of how I did mine:


And a shot of the finished product from underneath, before I put the mortar in the 8" circle area at the top:


And this my picassa link to about 8 pictures of how I did my vent.
Picasa Web Albums - Dino - vent trans

I did not use any screws for the anchor plate, but just mortared in that "L" shaped brick I cut to hold it in. I also saw no need for any insulation material between the plate and bricks. I kinda like this taller "transition" that angles the smoke up as it narrows. It draws really well. I would think you can do a similar transition to a clay pipe if you went that rout.

There are lots of good ways to do this and having a thread that shows people the various methods we did it is great. This transition (well the idea of, and how to go about it) was the toughest part of the build. So lots of pictures help

-Dino

[leckig]

Re: flue and vent opening

thanks! you too, Dino, used the duratech stuff. I am using el cheapo clay flue. I just mortared it in last night, we will see what happens. I surrounded it with just one course of bricks.

[Dino_Pizza]

Re: flue and vent opening

Checked out your pics leckig: your clay flue pipe looks good. Your arch rises a nice amount to the bottom of the clay pipe, so I bet it's going to draw air nicely. Good job.

[leckig]

Re: flue and vent opening

Thanks! The one thing I can say this oven sucks air like a shop-vac. I am at 600 degrees fires now, some small cracks, nothing major. Getting insulating blanket today.