36' low dome neapolitan style

[david s]

It is recommended that no more than 45 degree bend should be used as the draw becomes severely compromised. A horizontal flue pipe is likely to create smoke issues, which in your case, being indoors could become a big problem. once your flue is heated the draw won't be an issue, but at light up it's likely to be a problem. Some folk install an electric fan in the flue to overcome this problem.

[MarvinG]

I have been working again a bit! I'm pretty satisfied with the result, but it was a lot of work to make every stone fit. Inside where the air flows it's pretty clean and aerodynamic :-)

Now i'ts only about mounting the pipe. I think I have found a good solution. Since I have a double wall "home-made" pipe the inner pipe will go into the whole which you see. The outer wall will be on the bricks. Additionally the outer Pipe will be held by a slightly bigger pipe which I will (somehow) attach to the bricks.
Shall I use fireproof silicone for that? or drill into the stones?
I would not like to put any additional bricks to be honest.

cheers, Marvin

[MarkJerling]

Hi there

Today I spent a few hours cutting the final bricks for the chimney. Yeah - if I had bigger tiles I would go for them. But since I dont have and its not easy to find I made a little puzzle.

I'm not 100% sure how to make the transition to the pipe yet (pic #4). I would like to have a really solid mount since the pipes itself are very heavy, so there is quite a bit of force applied to this part. Any thoughts?

Thanks alot as always!

I think the shape of your squirrel tail looks good.

To answer your query: With mine, I cut a neat round hole in the tile under the metal flue and I cut it only slightly smaller than the metal flue diameter. That way, the metal flue (in my case, stainless steel) rests neatly on top of that tile. I then built up four courses of bricks around the pipe and filled the gaps at the corners between the round pipe and square brickwork. That supports the pipe nicely.

[NCMan]

Hi NCMan, I did not quite understood what you ment, where you'd suggest to grind. thx!
I'll make it all a bit more precise and hope to be able to have a big enough channel so i stay within 225 cm2 of my cross-section.

I wasn't suggesting to grind, only wondering if you were going to taper the opening the other way. Instead of the opening getting wider, perhaps make it angle the other way to begin to decrease as it goes into the tail?

[MarvinG]

Hi there

Today I spent a few hours cutting the final bricks for the chimney. Yeah - if I had bigger tiles I would go for them. But since I dont have and its not easy to find I made a little puzzle.

I'm not 100% sure how to make the transition to the pipe yet (pic #4). I would like to have a really solid mount since the pipes itself are very heavy, so there is quite a bit of force applied to this part. Any thoughts?

Thanks alot as always!

[MarvinG]

Are you planning to angle the edges of the vent to start a taper? It probably would help w/the draw a bit.

Hi NCMan, I did not quite understood what you ment, where you'd suggest to grind. thx!
I'll make it all a bit more precise and hope to be able to have a big enough channel so i stay within 225 cm2 of my cross-section.

[NCMan]

Are you planning to angle the edges of the vent to start a taper? It probably would help w/the draw a bit.

[MarkJerling]

That's looking very similar to mine. Just make sure your flue area, as you curve up over the dome, is no smaller than the actual vertical metal flue. With mine, I did not need any central support as my large fire bricks could span all the way across.

[MarvinG]

Good evening!

Today I have put back the bricks in the oven where the it-tool was. Super easy, but without a vacuum cleaner it could get difficult.
I have also finished the front arch, which I have cut again 1". So we have 8cm gap for the vent, and 8cm thickness of the front arch. I gained alot of space in front of the oven, thats great. Also the angles to work with it will be super easy.
I have also made up my mind how the chimney should look. Does this make sense to you how I arranged the stones. Will this hold?

The front arch I glued again with the store bought fire mortar. But I tend to use homebrew for the chimney because there will be big gaps.

Question:
- How Does this vent style look to your professional eyes?
- Shall I cut some notches into the "old" homebrew which covers the dome, or can i apply new homebrew right on top?
- How does one classically design the situation where the round metal chimney comes in?
As discussed, as long as the cross section of my chimney-channel is more than 6"^2, then i should be fine.



Thanks & have a good evening!

[MarvinG]

Thanks a lot for these helpful comments.

Yesterday I only has a few hours. so here a short update.
I have shortened the inner arch 2", and I have also shortened the outer arch 2". Therefore gained some space in front of the oven which will be very helpful I guess!!!
Tomorrow I plan to build it all up and then finally follow the squirrel tail chimney.

I think the arches are probably still more than big enough (if I did it again I would get rid of 3" more) - but not too big for a good performance.
Slowly but surely I want the dusty environment to finish.

[MarkJerling]

Just to double check:

- Is it correct that my door will be "behind" the exhaus exit. So it can only be used when the fire is completely switched off?!
.

Yes, the door seats against the inner arch, so your chimney will not draw air from inside the oven when the door is shut. You really don't want it any other way.

[MarkJerling]

Thanks MarkJerling

Today I manufactured the template for the front arch.

Just to double check:

- Is it correct that my door will be "behind" the exhaus exit. So it can only be used when the fire is completely switched off?!
- I was wondering if it would not be helpful to be able to regulate the fresh air coming in, like in a stove...does anybody do that or is this not necessary? Otherwise it's just luck if the chimney sucks too much or too little, right?

thanks!


Front arch - just tight with the ending of the stand




Vent opening with indications of the future squirrel tail - where the airflow will follow. Hope the dimensions are about right - it's pretty freestyle based on gut feelings. I was thinking of making it slighty more narrow and to exchange the two specially cut bricks with normal long ones - so it will end up where the marks are. Like this it seems a bit too big for me - all will go into a 6" pipe in the end.

As long as the part going up over the dome is not smaller in area than the flue itself, you'll be fine. In my case, I opted to make it slightly larger on the basis that it will be almost impossible to sweep, so I wanted to ensure I had enough volume should there be some sooting up. What seems to happen though, is that it gets so hot in there that any soot simply burns off.

[MarvinG]

A deep entry makes working the oven more difficult, requiring longer handled tools. It also makes the thermal mass of the gallery much higher and as it can act as a heat sink, it can draw heat away from the oven. So making the gallery shallower and lighter is advantageous. Unfortunately, building with brick units makes this quite difficult. It is a good idea to place wedges under the form to allow it to drop for easier removal. Many builders have damaged their brickwork because they omitted this important step. Removing jammed formwork is a problem.
The door can be left partially open to prevent some heat loss as well as providing enough oxygen to keep a fire going, although I usually find I either have the door completely out or completely closed. Jamie Oliver often roasts with the door off and a live fire in the oven.

Thank you david s
This is very helpful!! For me that means I'll redo the front arch and make it as shallow as possible (probably half as deep). I think a depth of the vent opening of 3" x 12" will be enough. I will therefore also grind half of the vent out on the existing arch, because I have the depth already. Quite a bit of work, but I read in your lines that it will be worth it.

[david s]

A deep entry makes working the oven more difficult, requiring longer handled tools. It also makes the thermal mass of the gallery much higher and as it can act as a heat sink, it can draw heat away from the oven. So making the gallery shallower and lighter is advantageous. Unfortunately, building with brick units makes this quite difficult. It is a good idea to place wedges under the form to allow it to drop for easier removal. Many builders have damaged their brickwork because they omitted this important step. Removing jammed formwork is a problem.
The door can be left partially open to prevent some heat loss as well as providing enough oxygen to keep a fire going, although I usually find I either have the door completely out or completely closed. Jamie Oliver often roasts with the door off and a live fire in the oven.

[MarvinG]

Thanks MarkJerling

Today I manufactured the template for the front arch.

Just to double check:

- Is it correct that my door will be "behind" the exhaus exit. So it can only be used when the fire is completely switched off?!
- I was wondering if it would not be helpful to be able to regulate the fresh air coming in, like in a stove...does anybody do that or is this not necessary? Otherwise it's just luck if the chimney sucks too much or too little, right?

thanks!


Front arch - just tight with the ending of the stand




Vent opening with indications of the future squirrel tail - where the airflow will follow. Hope the dimensions are about right - it's pretty freestyle based on gut feelings. I was thinking of making it slighty more narrow and to exchange the two specially cut bricks with normal long ones - so it will end up where the marks are. Like this it seems a bit too big for me - all will go into a 6" pipe in the end.