32 Inch Cape Build

[CapePizza]

After some months of reading and collecting information (mostly on the Forno Bravo forum site) I'm about ready to start gathering materials to start a 32 inch Pompeii style WFO.
First off, I'd like to thank the members of this site who've answered questions I've posted. Your help has be invaluable. There's a lot to learn and I assume there will be a lot of "on site" decision
making during the build. But thanks to the members who freely share their experiences and insights, I'm hoping to at least get off on the right foot.

I've been working out a design in CAD and I've posted some screen shots. I'd like to ask if anyone has any comments or sees anything that might be problematic to please let me know. Hopefully the flue is
winding up in the correct place. Even though I used the IT in the CAD to place and align most of the bricks, I'm sure there will be plenty of tweaking in the actual build. After some thought and research, I decided against including thermal breaks.

Thanks very much for taking a look!! I appreciate it.

John

[JRPizza]

Nice renders! Are you using Sketchup?

[CapePizza]

Hi JR.... thank you. I use Solidworks.

[CapePizza]

Today picked up 5 panels of 2 inch foamglas and placed an oder with FB for insulation blanket rolls and insulation board. Tomorrow picking up an angle grinder and 10 inch Diamondback wet saw from HF. So when the FB materials arrive next weekI should be starting. Geared up and ready to go.

A question I've been meaning to ask. I read somewhere on the forum (and can't find the topic or post) regarding placement of the insulation board and the 1st row of bricks. What I think I remember reading is that the insulation board should stick out a little from the brick (as opposed to cutting it flush with the brick). Am I remembering this correctly? And if so, what is the purpose of having panel stand out a bit (be proud of the brick) and how much should it stick out??

Thanks very much.
John

[Kvanbael]

I have my insulating floor stick out 2” beyond the dome because that is the thickness of the insulating blanket. So that the blanket can rest on that. And the edge of the calSil can be used to fix the chicken wire and hold the blanket.

[mongota]

Today picked up 5 panels of 2 inch foamglas and placed an oder with FB for insulation blanket rolls and insulation board. Tomorrow picking up an angle grinder and 10 inch Diamondback wet saw from HF. So when the FB materials arrive next weekI should be starting. Geared up and ready to go.

A question I've been meaning to ask. I read somewhere on the forum (and can't find the topic or post) regarding placement of the insulation board and the 1st row of bricks. What I think I remember reading is that the insulation board should stick out a little from the brick (as opposed to cutting it flush with the brick). Am I remembering this correctly? And if so, what is the purpose of having panel stand out a bit (be proud of the brick) and how much should it stick out??

Thanks very much.
John

I did the same as Kvanbael, I let my board insulation stick out a bit from under the floor brick. I don't know if there is an 'official' reason, but my thought was that not having the dome bricks right at the very edge of the 4" thickness of insulation board might help the insulation board resist compression from the weight of the dome bricks. It can also give you a little leeway in tweaking the overall size of the oven versus having to build it to the EXACT same footprint as the cut floor insulation.

I used four layers of 1" blanket over the dome. The first layers came down to sit on top of the protruding floor insulation, the subsequent layers covered the edge of the 4" thick floor insulation.

Regarding the possibility of altering the layout? Not a huge thing for me, but originally I was going to have a flared landing, narrower at the dome arch and wider at the vent arch. I decided somewhere during the layout phase to have a straight landing. To make it easier to install and remove the dome door with a non-flared landing, I simply increased the reveal of the dome arch bricks.

[CapePizza]

Thanks both for the insights. I like that idea of extending the board out from the brick. I'm planning on using 3 layers of the insulation however not sure if I'll have enough board(s) to extend it out another 6 inches (3 inches on each side for the 3 inches of insulation). And I also like the idea of keeping the insulation blanket from contacting the hearth surface as it might inhibit wicking up any moisture/water that might seep under the final render. Thanks again!

[CapePizza]

Some photos attached showing the start of my layout. I had tinkered with and revised the IT tool. I used the caster method but found there was a lot of play in the caster. So took it apart, removed the bearings and enlarged the hole where the harness mates with the base. Inserted a delrin bushing to make the tolerance a bit tighter and reassembled. That helped. Also lowered the hole where the arm mounts in the harness so it's more aligned with the center axis of rotation (not perfect, but closer to the center axis). I drilled a hole through the concrete hearth where the center line axis winds up and mounted a temporary dowel pin to the bottom of the IT plate to pencil in the layout using the IT. That concrete center hole can also serve as a weep hole.

[UtahBeehiver]

Remember that when you build the "L" bracket for the IT that line from the pivot point axis along the centerline of the IT rod intersects the midway point on the brick face, IE if the brick is 2.5" thick the intersect will be 1.25". Otherwise every this looks good. Make sure the pivot point is as close to the brick floor elevation as possible. I cannot tell if the IT rod is adjustable or not. Adjustable comes in handy to make subtle adjustments to brick courses.

[Ope-dog]

Hi Cape Pizza.. looks like you're off to a great start, IMO. I will be a bit behind you as I have my base up, however away on business for a month. So until I get back home in October, I get to sit in my hotel and live vicariously through you weekend warriors! UtahBeehiver and Mongota both have very nice ovens and I have been studying them religiously as of late. I have a question on your drawings maybe you could help me answer. I've been reading that the inner dome height should be 60-75% of the base ID. Did you factor this in to your equation and if so, what is the dome height you are working with? Your drawings are great. I've been a bit more old-fashioned with bar napkins and microsoft paint for when I'm feeling especially sporty. :-)

I look forward to seeing your progress!

[CapePizza]

Thanks for your comments, UtahBH.... I've read many times your comments in other posts about the benefits of making the IT adjustable. So I heeded you're advise. The bottom leg is square tube, the upper leg is square rod, so the upper telescopes into the lower. I think I'd be better with a treaded feature for adjustment, but what I have should work okay (hopefully). From the attached photo you can see I made a couple of interchangeable fixtures. One to hold the pencil, which has two fitting orientations, one holding pencil perpendicular to rod, the other in line with rod. This can be swapped out for the fixture that holds the brick with the centerline of rod in line with centerline of fixture and centerline of brick..so thanks for the direction with that.

Ope-Dog...... My base is 32 inches and the height of the oven should wind up around 16 inches. I am thinking of having it an inch or so lower (so maybe around 15 inches) by tweaking the IT as the dome comes together. In the Pompeii build literature put out by FB it references two styles of oven, Tuscan style and Neapolitan..... the Neapolitan having a lower dome. Maybe that is what you're referring to.

[mongota]

When I see a micrometer in the same pic as the IT, I know someone is working it hard, lol

It looks like you have the 1-1/4" offset that Russell wrote of. That really is key to keeping the inside faces of the dome bricks flush with their neighbors with no offsetting lippage. And having the IT adjustable will help as you go vertical. Again, exactly what Russell wrote...any vertical distance between the IT hinge's center-of-rotation for its vertical rotation and the actual floor height of the dome floor brick will cause the dome height to increase by that same distance as the brick courses approach the apex of the dome. The adjustments required, if any, are quite small per course.

I used a threaded rod inserted into a turnbuckle that was welded/fixed on one end. It was part of a screen door anti-sag thing I had laying around. Example, a threaded rod with 16 threads per inch will shorten the IT by 1/16th of an inch with each 360 degree rotation of the threaded rod. If you need to lose a half-inch as you go vertical, rotate the head of the IT once for each of eight courses. Worked well.

For me, it was the planning ahead that was difficult, especially the dome/arch interface. But once I started setting brick, it all became clear as my eyes saw the geometry of the build. And we do tend to make the builds more detailed or complicated than they have to be. Simply because we can. Because complicated means were trying harder and building better, right? lol

Congrats on the progress!

[CapePizza]

Question about the 1st row of brick (maybe referred to as "the soldier" row). I opted to configure this 1st row as shown in attached picture. I believe I've seen others who have used a similar layout. I can arrange these bricks so the tapered edges could be pretty close (maybe touching) to their neighbor's..... or I could leave a small space that could be filled with mortar as shown. Can anyone share any insights as to if it would be better to leave a space and mortar that space, or basically leave no space and butt the edges one up to the other? A side note, this image is just laying the bricks out. I do plan on putting foamglas and FB Insulating board down first. Thanks!

[UtahBeehiver]

Just so everyone is straight with the nomenclature of brick orientation, what you have laid out is what would be called a half header, soldiers are standing on end. Either way, this layout is fine, actually what is used as well.

[Ope-dog]

CapePizza , I really like how tight your first course looks. Question.. I've heard of an "angleizer" calculator somewhere on this site. Haven't found it yet. Did you use this to cut your first course or did you use a different method?

Thanks!