32 Inch Cape Build

[david s]

I would find your oven difficult to work because your entry is so deep. The smoke extraction can be improved if there is a much greater volume under the pipe. Ie an inverted funnel form so there’s plenty of volume for the smoke to collect.
Anchor plates are expensive and present problems if you drill into bricks to secure them, because drilling holes in brick and filling them with conductive steel fixings is inviting cracking of the bricks. If you do go this route at least make sure you use stainless steel anchors.

[Neil.B]

How comes you have different width bricks as you go higher and not straight on the outer arch/front, or is it the angle of the pictures?

[Ope-dog]

Hi CapePizza,
Your build continues to impress. I'll be eager to see how you progress on your chimney / flue construction. Do you plan to have insulation and brick surrounding your pipe all the way up, or at least for a few feet? If this is the case, does mounting it with bolts become necessary or would the anchor plate be overkill?

Also, where did you source the foamglass board under your CalSi board? I've seen this in other builds but haven't been able to find any available for purchase.

Thanks!

[mongota]

Question about installing the anchor plate for the flue pipe. I currently have one brick (each layer or row of bricks having just 1 brick in depth) to hold the anchor plate and I'm wondering if just having one brick
is going to provide enough support, considering the extra weight when the flue pipe gets installed and with high winds and all.

Would it be better to have 2 bricks so the "chimney" has a little more heft providing more support, or will the single brick be enough?

The other question is what is a good way to "fix" the anchor plate in place. Should it be somehow be bolted in place to the bricks it rests on.... or cemented in place. I currently was thinking of coring out a space
in the bricks it will rest on so it gets recessed into those bricks, and then the plate's flange get covered with mortar when the next row of bricks are installed.

Any help/suggestions would be appreciated. I've attached some CAD images of what I've currently got planned, but looking for thoughts about whether or not my plan is the best way to go.

Thank you!!

I have one layer of bricks (two rows of six bricks each on edge, for a total of twelve bricks) that provide the transition from my arched landing tunnel to a flat surface for the chimney anchor plate. My anchor plate is secured with four fairly small (1/4" if I remember correctly) expansion bolts secured in holes drilled in the bricks, and the plate as a whole is bedded in a heavy bead of RTV silicone. I've had a 4 foot length of 8" double walled chimney pipe on it for a few years now with no issues.

It's been through several good wind storms over the years, a few have lasted a couple of days and have taken down quite a few trees in the area. Last one was earlier this year. Nothing more than 60 knot winds. Roughly 69MPH. Enough wind where we lost power for 4 days.

[mongota]

The flared entry is coming along nicely! My oven originally had one, but I dropped it for a non-flared landing towards the end of the design process.

[CapePizza]

Thank you all very much for your comments.

mongota , thanks for your detailed explanation of what you did for your chimney/anchor plate set up. I do remember you saying (somewhere) you had originally planned for a flared tunnel. Now that I've got that underway, due to my oven opening being a bit small, I'm glad I opted for the flared tunnel. I can see the "flare" will make a difference when using the tools and for viewing what's cooking. The depth of the tunnel is sort of dictated by the dimensions of the mounting flange of the anchor plate. I'm using a 6 inch flue pipe so the anchor plate has a 10" square flange, so the length of my tunnel worked out to be 13.5 inches in depth. I suppose some folks opt for not using the anchor plate. I like having the option to secure the flue pipe in place, thus the name, "anchor". Those flue pipes are rather hefty (I purchased a Duravent stainless double wall 6 inch pipe, which actually works out to 8 inches OD. The one I have is 60 inches tall, as it will fit through the roof of a pergola type structure that overheads the oven. So I can sort of anchor the top of the flue pipe to the pergola structure. Anyway..... I've been looking at your photos, Karangi Dude photos and some other member's photos, and also photos of another builder who did create a flared entrance whose screen name is oasiscdm. He had a very nice outcome and great photos of his oven build.

Ope-dog the bricks go up the flue pipe only the thickness of 2 or maybe 3 layers of brick, thus my concern for making sure it's "secured" in place. I do plan on placing insulation blanket (maybe just one layer) and P-Crete up to the first brick in the chimney, but covering the exterior of the tunnel. As far as the source where I purchased the Foamglas, they are in Massachusetts. I found another distributor in New Jersey. I think if you just google around you can find a distributor near where you are.

Neil.B the bricks are shaped the way they are as that is what worked out in the CAD. I think if I had left the bricks the same width, as you alluded to, there would have been larger mortar joints than I was looking for. In the end the shape of the bricks did not reflect exactly what was in the CAD, but so far it seems to be working. Onwards and upwards.

Thanks again for the feedback.

[Neil.B]

Looking forward to seeing it complete.

[MarkJerling]

Sharing some photos of the start of the flared entrance. Hoping to start installing the flue gallery bricks tomorrow.

If anyone has any thoughts about the questions asked in my previous post above this (post #179), I'd appreciate hearing your thoughts.

Thanks.

Very impressive! I look forward to seeing it completed.

[Frank C]

Hi John,

Still studying your progress and very impressed!. It looks like you started with some tapers on L1 but less or none after that. After trying to model in SW and seeing the complication of the 'inverted V' - I get it. The 'inverted V' is the issue, not the taper as you to up. I know UtahBeehiver has covered this but it really didn't click for me until I tried to model it.

Wondering, did you try to model those bevels in SW? I can see the bevel is needed - the taper, not so much. I nailed it on one plane - level3, then realized that it tapers in another plane as well (of course it does). And then how far back to bevel? And what an awkward angle to cut! I keep thinking and wondering and googling about the heat retention of fire brick vs mortar and the depth of that bevel and taper or lack of taper.

As a side note - I'm pretty sure it's easier to just do it than analyze it. What was that - analysis - para? Ugh. I've been watching these builds almost obsessively for a few weeks now and I'm sure there's a lot more in the forum, but your build and mongota (also in CT) (particularly his post #60 on the arch) has helped clarify a LOT. Thank you guys. Still planning...

[Frank C]

I should have said 'bevels in another plane as well'.

[CapePizza]

Frank C Hello. I did model the bevels in SW. I kind of "built" the whole oven in SW using the CAD created IT. For me it was like building a model and the SW documentation was like the illustrated instructions. It gave me a place to start when I got to cutting the brick. That being said there is still a lot of changes that occur that differ from the CAD due to a number of factors the CAD doesn't take into account (mortar differences, cutting inaccuracies, error, etc.). So at some point you depart from the CAD and go by what the build needs, but the CAD is a good place to start and you use it as a guide.

I've attached a screen shot originally posted by Russel (Utahbeehiver) which refers to explaining the bevel/taper/angle. If I remember correctly I did not "bevel" the first and maybe the 2nd row. I did angle all dome
bricks. And to not wind up with the inverted V, I did bevel and taper all the bricks in all the remaining rows. I created a compound mitering jig of sorts and that came in very handy to cut the angles and bevels. And when you get to placing the bricks, if you do wind up with a slight inverted V you can take an angle grinder and shave a little off one of the butting bricks to make the fit flush and get rid of the inverted V. So a little bit of hand work.

As far as modeling the tapers and bevels in the CAD, the way I did it was to create one brick (the "seed" brick) and place it into position using the CAD created IT. Create a vertical axis that comes off the center point of the dome. Then do a circular pattern of that seed brick to create the row. This gives you an idea of what kind of angle you'll need to create to make it so there's no V. You create an angle and bevel on one side of the seed brick and mirror it to the other side of the brick. (or, better, after creating the bevel angle you can just do a surface cut to remove half the brick and then mirror the 1/2 brick remaining). So now when you tweak the angle/bevel, both sides of the seed brick will update. All your bricks in the circular pattern will update to reflect what's going on in the seed brick. You keep tweaking the seed brick until you get it so the butt edges are parallel (no "V"). I used the sweep cut feature to create the cuts creating the bevels /angles. I hope that helps.



I did find Mongo's post #60 very helpful to understand the arch.

Good luck.

[Frank C]

Thank you John!
Hoping to make some progress on my model this weekend.

[CapePizza]

Installed bricks that will shape the chimney flue today. If the weather holds out will try and install the front and back chimney bricks tomorrow. Hoping to at least get the chimney done before the winter cold weather sets in. I think if I can at least get the anchor plate installed I'll have reached my goal for now and will wrap it up for the winter. Wish I could keep working on it but need to heed Mother Nature.

[Baza]

CapePizza I'm absolutely blown away by your progress!!! WOW!
Love the thought going in to this.
You've taken on more cutting and detail than others may feel necessary - but you have made YOUR oven - and it's fantastic - I think we all agree!!

I feel your pain packing it in ... but something to look forward to in the Spring!!
This has been a fantastic run watching your build, mods and questions ... we've all benefited!!

Well done mate!
Much to be proud of!
Barry

[CapePizza]

Thanks for your nice words, Barry Baza. Tried to work on the front chimney bricks today. Got one brick installed, but cold weather got the better of me. The temps are supposed to rise on Wednesday into the 60's, so will pick it up back then.