My Oven/BBQ

[beammeup]

Re: My Oven/BBQ

OK thanks Marcel. Leepin what kind of clading is on the outside of your fire bricks? Concrete or some refractory material? That crack looks pretty substantial. How much time did you give it before your fires? I'm asking because I havent had any big fires in mine yet, so I'd like to try and avoid any cracks as I already applied the insulation layer (5"-6" vermicrete).

[Marcel]

Re: My Oven/BBQ & taller vent is good

(B)

Sorry to bud in here but I have a question for JC. You say more flue would give a better draw?

(M) I agree with a taller flue. Virtually every posting I've read also supports that view.

(B) I have almost finished my oven , I am using 8" stainless pipe 1m vertical 45 deg joint then 1m on the 45 diagonal then 45 deg joint then 1m back up at the vertical. This is to go around an outdoor porch roof rather than through it.

(M) I also had to jog, but for a different reason. I wanted to avoid contacting my ridge beam. Click below to see images of those flex elbows:

http://www.fornobravo.com/forum/f21/marcels-pompeii-oven-photos-part-6-a-413.html

(B) The pipe is fabricated but I havent put it up yet, do you think it will draw OK? My curing fires the smoke went up the vent (without the pipe) pretty good. I am a bit worried that with so much pipe and the diagonal it wouldnt draw well.

(M) Just the opposite. A taller chimney keeps a distance from your fire so that turbulence won't send smoke back down and smother your fire. Also, when the metal flue gets hot, it keeps the smoke rising.

(M) You may have some initial smoke out the front of your oven before the flue gets hot enough. Once you have a roaring fire you should have hardly any smoke, even out the vent!

(M) I will be attaching a metal shroud this spring to direct the smoke around the roof peak and when I do, I'll post pictures of it.

Ciao,

Marcel

[Leepinla]

Re: My Oven/BBQ

#3 curing fire went well.
One small crack on the outside of the vent, (not bad)
After all curing fires I will fix the crack
The dome looks great (no cracking at all)
Bricks will burn clean todayJ
Leepin

[beammeup]

Re: My Oven/BBQ

Sorry to bud in here but I have a question for JC. You say more flue would give a better draw? I have almost finished my oven , I am using 8" stainless pipe 1m vertical 45 deg joint then 1m on the 45 diagonal then 45 deg joint then 1m back up at the vertical. This is to go around an outdoor porch roof rather than through it. The pipe is fabricated but I havent put it up yet, do you think it will draw OK? My curing fires the smoke went up the vent (without the pipe) pretty good. I am a bit worried that with so much pipe and the diagonal it wouldnt draw well.

[jahysea]

Re: My Oven/BBQ

More flue would help the draw as well. Is the plan still to go upward from the center with more chimney?

[maver]

Re: My Oven/BBQ

That 3rd picture shows the smoke layered in the oven (before the temperature gets too hot for smoke as it will with your later fires) - I like it. Also, same picture, your oven entrance picture shows good work with the way you tapered up the vent, a good picture for other oven builders to look at. Now you are starting to have fun with fire! I bet as you get the oven hotter the chimney will heat up and draw more efficiently so you don't continue with the "leak" of smoke you have out the front opening as seen in the first picture.

[Leepinla]

Re: My Oven/BBQ

Well then Here we go.

[jwnorris]

Fire in the hole ... [was] My Oven/BBQ

Can I build a fire today???????????

But, of course. Follow the curing fire instructions and enjoy.

J W

[Leepinla]

Re: My Oven/BBQ

yes I am, Maver,
the run is only to the middle of the dome
it's all going up, and looks like it will draw (from the smoke from my cig)
but I plan on eatting before I insolate, so if its no good I will take it out and go strate up in the front like every other one.
can I build a fire today???????????

[maver]

Re: My Oven/BBQ

It appears you plan to apply a vertical chimney pipe at the rear end of that horizontal run. Will you temporarily apply the vertical pipe (perhaps with bracing wires or rods) and test the draw of your chimney prior to fully cementing in that horizontal run?

[Leepinla]

Re: My Oven/BBQ

Its Done.....
now I just sit and look at it
For how long???????????
heres some new pic's

Leepin.

[Leepinla]

Re: My Oven/BBQ

Yes I saw that, thank you, that?s what I was thinking about,
But then the cleaning part came in.
Looks like after some time,
I will just have to clean it with a sledgehammer.
AND THAT MEANS
The next home owner will have to clean it (hahahahaha)

I see that they sell a stainless steel flex pipe as a chimney liner.
What about that kind? Ridged or flex, once it?s covered in refractory mud, then it?s a cement pipe? Or are the gasses that hot?
I have looked at the oven and can settle on a more strait up designL
But it dose not fit the vision.
It?s raining here today, so I think I?m going to look into this chimney thing a little more. Any advice is as always most appreciated.
Thanks.
Leepin

[christo]

Re: My Oven/BBQ

Here's an alternate route about 3/4 of the way down the page. May not be what you want but may start some ideas....

MHA News - 2006 Meeting - Backyard Oven with Peter Moore Has an oven that vents from the front to the back via a brick channel on top of the dome.

This oven had a of the topics we've been talking about lately incorporated into it and then some.....

Christo

[maver]

Re: My Oven/BBQ

I wanted it to sweep back and up from the middle of the dome.
If I use metal flex vent pipe and cover it in mud,
Then I can use a round brush on like a flexible snake.
Do you think that will work? And how much cleaning do you have to do?
Is it as bad as or worse than a fireplace chimney?

I have a rectangular terra cotta chimney that I have so far not needed to clean, although I've only had my oven operational for about four months. I agree with JC that flex metal pipe is not ideal. The gases from the oven are quite hot with almost no particulate once it's up to temp, but as you are bringing it up to heat you do release soot and creosote, so not as bad as a fireplace chimney.

[jahysea]

Re: My Oven/BBQ

Hi, my thoughts having recently gone through this.

There is a helpful thread on curing here:

http://www.fornobravo.com/forum/f16/oven-curing-767.html

But in short, if you finished your dome on the 20th, cooking on Christmas day is out. You COULD light your first curing fire, but everything I've read recommends at least a week of curing before doing that. Low outdooor temperatures would extend that curing time. I waited a week in fairly moderate November northern California temperatures.

Don't insulate before your curing fires unless it's temporarily with an insulation blanket. Cracks are likely to develop in your cladding, and you want the opportunity to seal them before applying the insulation.

If you are going to insulate with perlcrete/vermiculite concrete, then either cure first, or apply the insulating layer(s) and wait 7 days minimum for them to cure as well. Perlite and Vermiculite soak up water, so that mix takes a long time to dry out.

Pizza for NY Eve is compelling, I know. If it were me, I'd not insulate, and starting about the 26th I'd run two curing fires a day till NY. You can light a curing fire in the AM, let it go out, let the dome cool, then light another in the late afternoon. Progressively hotter, like in the instructions.

Flex pipe doesn't sound like a great idea for chimney to me, seems like from the pics 1 straight piece to the dome tip, 1 angle and straight up would achieve nearly the same thing. Flex pipe would be harder to keep clean.

good luck!