OctoForno

[Mistertoy]

Re: OctoForno

Thanks for the instructions John...

I had done some of the steps before but it was not working out or clicking with me.

I have got it now ... I spent a bit of spare time on the weekend after your post working it out and marking out. Then I thought about it that night and I still had it wrong !
Had a re-look the next day and made up a few IT attachments to help marking out, did quite a bit of measuring against my plywoord template and decided tapered the outer bricks facing into the oven (rather have the whole inner surface of the arch straight) and I was now happy that I had it right.

Appreciate the advice... I am pretty confident it will work out nicely... time will tel, anyway too late now I have done the major cuts !

Picture attached - only the outer bricks to go which will be straight forward.

Brett

[GianniFocaccia]

Re: OctoForno

Brett,

I know right where you are in trying to visualize your arch config. Here's how I did it.

Make a (36"?) template out of plywood to match the curvature of your dome. If you're using an IT it will be easy. Then measure the distance from your floor center to the inside of your inner arch. Cut your dome template (vertically) this same distance so it will fit flush up against the inside of your inner arch form. (see photo below).

Start your arch by cutting the center-top brick. Use your indispensible tool (or a piece of string) to figure out the upper angle. Use the profile of your dome template to figure out the lower angle. (OctoForno post #34). Once you have these angles figured out go ahead and cut the rest of your arch bricks, but only the tapers, not the inside radius. If your bricks are tapered this is one less step for you.

Once all your bricks are tapered and held in place with shims, scribe a line using your IT/string from the back of your center-top brick to the back of your last brick on either side where it meets the dome. This will give you the cut line for the inside of your arch.
Match the top and bottom angles from the center-top brick for each adjoining brick and you're there.

If this sounds confusing let me know and I'll sketch something up. Hope this helps.

John

[Mistertoy]

Re: OctoForno

Hi John

I have been reading the posts by yourself and ggoose (Gene) about the arch transition.... I am aiming to do a that sort of transition to avoid the upsidedown "v" with my nearly 36" pompeii oven.

I have 3 bricks high (75mm bricks) straight sides on the entry with a arch of tapered bricks. I am struggling to work out the downward and upward tapers on the inside of the dome. I have done some work with the indispensable tools but it is not clicking with me.

The way I am thinking at the moment, as a point of reference I need to extend the arch bricks into the dome so the highest centre brick lines up with bottom edge of the row of brick that join above the arch otherwise I will have a v gap... If I have this point maybe I can work back from this point. Not sure if that makes sense. am on on the right track ?

Any additional help or hints would be appreciated.

Thanks
Brett

[garch]

Re: OctoForno

Thanks John and Dmun.

Your input really helps, I really thought that this gentleman was wrong, but I feel much better with both of your input. Bought my HF saw yesterday, a week of vacation and on to the dome. Thanks again,

Gregg

[GianniFocaccia]

Re: OctoForno

Gregg,
The oven floor and dome rest directly upon your insulation layer regardless of whether the first course has been built on top of or around the floor. Like dmun says, any direct contact of the dome with the structural layer will leak continuous heat through conductivity, requiring an inordinate amount of fuel to reach and maintain pizza temps, not to mention greatly shortening your retained heat curve.

John

[dmun]

Re: OctoForno

This gentleman was telling me that the outside of the dome would need to be anchored to the structural hearth, otherwise the dome will collapse over time.

Over time? Like in thousands of years? It's quite possible. For our lifetimes? Unless your dome in on a trailer on the public roadways all the forces are down. As the riggers say, gravity always wins.

Any method of anchoring the dome to the structural slab will create thermal bridging that will be a lot more of a threat to pizza than imaginary sideways forces.

Insblock19 is pretty water resistant. My build was partly open for the better part of a year, and I didn't notice any degradation of the block.

[garch]

Re: OctoForno

Thanks John, I picked up some board yesterday after reading your input. I found a local dealer who carried the product.

This gentleman was telling me that the outside of the dome would need to be anchored to the structural hearth, otherwise the dome will collapse over time. I dont remember anybody with that complaint, your thoughts?

Thanks again

Gregg

[GianniFocaccia]

Re: OctoForno

Thanks, Garch. My insulation does get wet from time to time whenever I forget to cover the oven with a tarp. It always dries out though. There is a slight indentation in the exposed part of the Insblock where it has abraded, but that is from my shoes stepping on it, not water. (I'm too lazy at this point to cover it with plywood). I figure this section will get covered with ceramic blanket anyway.

John

[garch]

Re: OctoForno

John

I have been watching and admiring your build for a long time, you really set a forum standard.

I read that you used ins block 19 underneath your floor. My build will be a while to completion and i was wondering how the insulation will hold up to the weather, mostly getting wet from the rain. Will it breakdown after wetting than drying?

Thanks,

Gregg

[gmchm]

Re: OctoForno

It looks like your giving a "school" on dome building. gmchm

[GianniFocaccia]

Re: OctoForno

Chip,

The vertical indents go down directly on top of the course below. I make the same shallow indents on the bottom course of bricks - only they are perpendicular to the vertical indents that go on top of them. In fact, the bottom course indents are two complete circles I grind once the prior course is set.

The 'D-shaped' scallops go on the sides of the bricks. For a brick that I've just mortared in, the exposed side has the D scallops with the the flat side closer to the front of the oven. This way, when I press the next brick into place, the flat side of the scallop acts as a 'stop' for the mortar attached to the new brick. The new brick has a set of scallops in the opposite direction - the flat side is closer to the exterior of the oven. This way when I press the brick into place the rearward flat side acts as a stop.

I know that may sound confusing, and if it does let me know and I can draw it out so it makes sense more easily. All I know is that once I tap the buttered brick into place I can let go immediately and the (vertical) brick is firmly glued to it's adjoining brick.

John

[GianniFocaccia]

Re: OctoForno

Dino,

Please excuse me for using the 'all-too-familar' transition pics! BTW - Have I ever told you you have a great-looking hand? It's just that the triangles kind of emphasized the construction challenges inherent in the FB plans. Hope you don't mind.

The dome has half of the 11th course to go and then two more and then the plug. There are 13" spanning the remaining open space. I'm getting antsy to get it closed up and start work on the entryway arch(es).

Any advice you can share on building the entry and flue gallery will be humbly accepted.

John

[mrchipster]

Re: OctoForno

I have a question as to the orientation of your little moon cuts. One side appears to be vertical and the other a shallow scallop. Which side faces down whwn you place the brick?

The arch design is great I am glad I found these posts before I start cutting brick in a couple of weeks.

Chip

[Dino_Pizza]

Re: OctoForno

Doug,
I got the idea after looking at the inside transition pics of builders making the crazy cuts to merge the converging circular dome walls with the linear inner arch plane.

HEY, I resemble that remark! I thought my hand looked familiar.

I actually ended up not mortaring those silly triangular pieces in after someone talked some sense in to me (dmun or Les perhaps?). They said little pieces like that may end up chipping off anyway.

Your method, John of angling the inside of the arch to accept the ring-rows is probably the new standard. Is your dome still open or do you still have a few more rings and the 'cork' to do?

Good job with your cuts, you've got a nice tight dome.

-Dino

[GianniFocaccia]

Re: OctoForno

Well, I was about to say: Oz - 2, Yanks - 1, but I forgot about Gene (ggoose) in Spokane WA. He's made a real first-rate mockup on Post #22 here:

http://www.fornobravo.com/forum/8/28...tml#post114621