Pdx 42" update

[david s]

The outer arch needs to have a bigger radius and the vertical bricks supporting it about an inch wider, creating a rebate so a door will fit against the inner arch.
Here's an example of a stainless fabricated transition.

[Macrinehart]

Well - I had to let the motar set up on my 11th course, so I jumped to the opening arch and just dove in I decided to put the 3.5" arch on the outside, with the throat to the chimney going back to the inner arch. I figure I can use the fiberglass rope gasket to help seal the inside arch, and I'll get some thinner rope gasket material to help get a good seal on the custom transition to the chimney. I think it looks pretty good.

[Macrinehart]

This might be the weekend that I close the dome...

I'm about to head out, but before I do - I have a few questions on the outer arch, flue and chimney. With a 42" oven, I'm planning on 8" chimney (stainless steel), which has an opening area of about 78 sq inches. My plan is to have a rectangle opening in the outer arch, about 5.5" x 12", and to fabricate a custom flue transition. That leaves 3.5" of brick to work with around the front and/or back of the throat/opening. This presumes the depth of my outer outer arch is 9".

I also have 7/8" fiberglass rope gasket that I planned to use to seal between the inner and outer arches to allow some space for the dome to move.

Before I start cutting bricks for the outer arch, I want to verify this approach to the chimney opening is sound. Also, I'd like to know if I should have these very shallow arches in front and behind the flue transition? Or perhaps I should extend the depth of the outer arch with an additional course of bricks? Or maybe go for a wider opening, such as 5" x 16"?

Thanks for the advice!

Mac

[UtahBeehiver]

That should work and luckily you do not really have that many to do. You really only need the do the conflicting area (inner dome area) say the first 1 1/2-2" and let mortar fill in the back side. IMHO, use the brick you bought.

[Macrinehart]

I decided to experiment with one piece. Not sure on the results. On the positive side it fits very tight to the place its intended for. But the angle cut on the inner face means the bottom depth is reduced which causes the outside bottom to be recessed about a quarter inch inside the outer curve of the dome. Not sure if that is an issue?

[Macrinehart]

Might even be more like 1.5" wide inside dome.

Well noted. I was busy marking up my bricks with a 2" outer bottom width, which results is a 1.7" inner bottom width. I got your point though. I will attempt the feathering as suggested. I wonder if I should take the angle grinder to the inside edge of the dome to round off some of my sharper angles on the 10th course for a tighter fit?

(It seems like a good idea, but I suppose I worry about messing things up. Maybe instead I should dry fit the next course and take off somw sharp edges for a tighter fit to the existing inside top edge of rank 10)

[UtahBeehiver]

Might even be more like 1.5" wide inside dome. This lessen to cord distance and I also slightly curve the brick as well by just feathering on the wet saw and only near the interior of the dome face.

[Macrinehart]

Thanks Russel. It also appears you've opted for narrower bricks at this point. Possible going to an outside bottome width of about 2 inches instead of 4. Is that about right?

cheers,

Mac

[UtahBeehiver]

IMHO, I would shoot for smaller internal joint size, the external joint size is not as critical. I found at this point in the build you have to customize the bricks to minimize internal joint size. This is the hottest part of the dome and mortar is more subject to break down. Notice how I had to curve the inner face of the bricks.

[Macrinehart]

Hi folks - I think I may be at the final course before the plug on my dome, on course 11. At this point the gaps for the mortar joints are getting a little triangular. I laid a si gle brick yesterday to start, but after dry fitting the next brick I feel like I need to do mor side tilt and side angle on the remaining bricks to get a good fit.

To assess, I went back to the dome calculator spreadsheet and adjusted the pivot point height and mortar width settings until I got about the right brick count for courses 7-10. This seems to confirm my assumption. The original side tilt was 16.6 degrees, but the revised is 19.8. And original side angle was 4.6 degrees, but revised is 5.3 degrees.

I'm wondering - If I trim this excess material off, should I get a better fit? Or just fill the wider gap with mortar and not worry about it? I'm taking a pause to wait for advice. Attached photos illustrate the point.

(Note that the mortared brick is cut with the original angles. The dry brick has a 20 degree tilt but the original 4.6 degree angle.)

[Macrinehart]

Thank you UtahBeehiver! I'm wrapping up today with a trip to the DYI heating and cooling center shop for stainless steel chimney materials. I've got to refresh my memory on the opening size for the chimney and hight recommendation. Ultumately I'm going to build a shelter over the oven but first thing is finish the oven.

I layed my first brick for course 10 but I'm headed back to work tomorrow so hope to wrap up closing the dome this weekend, as well as building the outside arch.

Cheers,

Mac

[UtahBeehiver]

Should not be an issue at this stage of the build. Droop typically start at the first course above the arch and you make tilt adjustments gradually and you go up. But you at almost to last course then a plug so onward you go.

[Macrinehart]

Let's see, my wife has been saving a 2022 Barbera de Monferrato for a special occasion. If it lasts that long then that could be it.

The 9th course is now complete! I believe I've started to get a little "droop" toward the front, as indicated in the photo below. It doesn't seem too significant, and I'm tempted to not worry too much about it. This has been developing over the past 3 courses but the bubble is still half in the level indicator, and with only 3 courses remaining I don't think it will impact me much.

If the pros disagree with my assessment, please let me know. Thanks!

[Frenchie]

Great progress, you can almost hear the first curing fire cracking away. Have you decided what wine you’ll drink to warm by the curing fire to celebrate?

Very nice inner arch, I have oven envy.

Not far to go now, keep it up

[Macrinehart]

I'm moving along now! The 8th course is finished and I've set a couple of bricks for the 9th course. The slope is now steep enough that wet mortar will not hold the bricks in place.

I found that each of my courses is using less bricks than projected in the excel template. I got through the 8th course with 20 bricks, about four less than planned. Four less than planned seems to be the case since the 7th course. Fortunately I haven't been cutting all the bricks called for the the plan in advance, so no material lost. However, I still think I could be short on my brick supply. I may need to do a 3rd run to the landscape supply yard to finish the dome.