32 Inch Cape Build

[CapePizza]

Reworked the design for the thermal breaks and how the chimney bricks will be situated (images attached).
Still working on the exact size of the brick openings as they transition to the anchor plate.

Thank you again for all your comments.

[Baza]

LOVE this John!!
I do not have CAD or anything like it so appreciating your efforts and sharing here!

It looks like you have solved the heartbreak question you've had completely!
Your floor one seems like it will do a fantastic job - much better than my ribbon and slight gap!

QUESTION(S):
1. The bricks facing your oven opening (that you've notched for the rope) - will there be a gap at the bottom? I ask because I've read that the fibres of the rope are not welcome to fall out and potentially on food? are you putting high heat caulk below it to prevent this? Or just leave the slight gap between the dome entrance and first arch? If so - how much of a gap?
2. Are you using 5 panels in your arch mold design? Mongo has 2 and I'm thinking 3 - possibly 4? Is 5 a better option?
3. How large will you make your opening for the chimney in the vent assembly? I see you are thinking that next - I'm sure you'll share as you have been.

Sorry for all the questions - you are doing great work and we are all benefitting!
Take care
Barry

[CapePizza]

Hello Barry Baza. As you know, I'm certainly no expert with vast amounts of experience here :-) But just kind of going on my gut. Being able to work all this out in CAD has been very helpful, especially all the angles for the flared arch. In answer to your questions about how I think I'm going to handle things (and of course I'll also look to hear what others have to advise, as well):

1) Any gaps that are there facing the oven opening I'm planning on filling with P-Crete to hide the rope. If the P-Crete cracks, it cracks.... but it won't be like using mortar. I suppose using a high temp caulk is another solution, so I'd like to hear what others might say about that.

2). I just put 5 panels there when I was working on the CAD. The thing I'm trying to be cognizant of is since I'm using cut bricks (different sizes), I want to make sure they all get supported and don't start tipping due to there not being a support where one is needed. 5 panels might be overkill.

3). I'm using a 6inch flue pipe. I think I read on your thread you're using 8". As of now I was going to make an 8 inch opening brick opening and kind of either round off or chamfer the corners of the intake so the draw and smoke flow more efficiently. I've seen others do that, as well. But I have to do a bit more research on that.... not there yet.

Hope that all helps.... again this is all new to me, so I'm learning as I go... but, as you know, more than happy to share what I learn (successes and failures alike). Speaking of failures, the row 8 I did with the 3 bricks as anchors spaced 120 degrees from each other was a total boondoggle. Caused more problems than solutions. I don't recommend that.

[Baza]

WOW - THANK YOU JOHN!!!
This TOTALLY answers my questions and gives me a great deal to consider!
And, yes, I tried the anchors throughout the circle and they were a disaster for me too! HA!

Thank you again - this was really helpful!
Barry

[Kvanbael]

Based on these great illustrations, I'd like to share 2 comments on the design:

1. Your nice arch curve is already somewhat flat at the top. By fanning out the entry, you get an even flatter ceiling, which might be challenging to carry the weight of the chimney.
2. The chimney pipe ends in the arch ceiling, so there's not really a vent shape to guide the smoke upwards. You might want to sculpt the arch bricks to create some more space there and/or have the front-most arch bricks go lower to stop the smoke.

[CapePizza]

Thanks for your comments, Kvanbael. I know what you mean about the flared arch tunnel flattening out at the top, so... I am thinking about the weight of the chimney bricks. One thing is I'm not planning on building a massive chimney (at least one with a lot of bricks) so hopefully that may help having less weight. Thanks for your observation.... and I'll give that some thought.

The other issue you mention, that's not yet the final design for the chimney's interior. I'd like to taper the bricks (wider at the bottom and lessening as it reaches the flue pipe... but haven't finalized all that yet. But thanks for mentioning it.

I should be getting the flue pipe, anchor plate and chimney cap next week and the first thing is I have to make sure that I ordered the correct anchor plate. I ordered a 6 inch double wall stainless DuraVent pipe and a 6 inch anchor plate. I was just looking at the spec sheets and the ID of the anchor plate flange is 6 inches and the exterior of the pipe seems to be 8 inches. I can't tell from the drawing if there's a smaller flange on the bottom of the pipe that mates with the anchor plate. Will have to wait and see how that all works once I receive those pricy parts.

[Neil.B]

Hi John, these are my double walled 6" flue,
the anchor plate is also double walled.
I've taken a picture of the bottom of the flue so you can see how it slots together.

[CapePizza]

Thanks for showing me that, Neil.B. From what I can see from your photo the ID of the outer wall of the pipe slips over the OD of the flange on the anchor plate..... and the OD of the inner pipe, likewise, slips inside the ID of the flange on the anchor plate. Makes sense. Again, thanks for showing this....I appreciate it.

[CapePizza]

Kvanbael Thanks to Kvanbael for getting me to re-think the flatness on the vent arch. I think the previous design "may" have held up, but I was feeling uncomfortable enough to go and revise the layout. Made it more rounded on top which I think will do better under the weight of the chimney bricks. With this layout I may put some buttress bricks into the mix, as well.

One question maybe someone can help with their thoughts.... I'm thinking the flue pipe should be as close to the oven arch as possible, while still leaving enough meat on the bricks that are next to the opening arch to support the anchor plate and flue pipe. Right now I'm wondering if the flue pipe/anchor plate should be moved back towards the dome a bit. Appreciate hearing any thoughts. Thank you.

EDIT: I should have mentioned the reason for my thought about moving the flue pipe back (maybe obvious), I'm afraid of smoke/heat exiting the oven front rather than going up the flue. I suppose another thing I could do is bring the front arch tunnel out more, increase it's length a bit. Thanks in advance for any feedback.

[Neil.B]

Why are you angling your vent arch bricks and not laying flat? I personally think you are creating a lot of work and wastage for potentially no benefit.

[CapePizza]

Hello Neil.B. When you say "angling your vent arch bricks and not laying flat" I'm assuming you're referring to why is the vent arch flared out instead of just straight out from the dome. I mentioned in a previous post I'm planning on a flared tunnel mostly because the oven's opening is on the small side (only 16 inches wide by 10" tall. Having a flared tunnel will allow for more maneuvering of the tools and provide a wider view to see inside the oven. Plus I think it looks cool. I suppose there's been some debate on the forum through the years about whether it serves a benefit or not considering the extra work and planning involved.
I'm into making it work.

On another note, I'm hoping someone can chime in on placement of the flue pipe with regards to how close it should be to the dome (mentioned in post #159).. Thanks!!

[Kvanbael]

I would put the flue as far to the back as the construction will allow. Adding extra depth towards the front mainly helps against side winds, at the expense of making it harder to reach inside the oven.

I would only bother to taper sideways (not depth-wise) and at the same time try to create some kind of lip at the front to break the flow.

Here's a video of my oven. Note that this is exceptionally smokey (probably a damp piece of wood and the oven just getting started), but it shows the kind of airflow you want to get.

[CapePizza]

Kvanbael Thanks for sending that video. Yes, a bit smoky () but certainly draws well. Your oven looks really great.

I'm still fine tuning the front arch tunnel layout, including the flue gallery. Good point about just flaring the sides and no real need to taper the front and back brick.

You sure do have a beautiful landscape there. I've noticed that every time I see a photo of your oven. Nice.

Thanks again for your help.

[Neil.B]

Hi John,
Yes, I wondered why you were flaring up and out. it makes sense with a small opening.

[CapePizza]

In researching curved arches a lot of images came up to kind of marvel at.

And, yes..... I feel like my brickwork skills have improved an ever little bit.... ever so slightly,......since starting this WFO project.

I'll know I've reached the tipping point when I can make an oven like this.