31"/800mm in Eindhoven, the Netherlands: Design critique and build topic

[Toiletman]

Thanks for the support gents!

RandyJ The curing fires are going to be in spring. It's getting pretty wet here now in Autumn and I don't see much sense in trying to keep half-fitting blankets dry in that weather. I'll use the winter to cast a gallery-->chimney connection and then be ready to fit it and insulate the oven in spring... and then finally pizza time hopefully!

Looking good!! And glad to hear it remains standing! Your brickwork continues to be so impeccably clean, I'm kind of embarrassed to upload pictures of mine :-)

I built my vent arch last weekend, but have kept the form under it until I add some buttressing. That should happen this weekend at the latest. The flue hole in my arch is a lot smaller than yours (starting opening is about 10" x 7"), but should still be plenty large for its purpose, I hope.

You're only seeing the 'after cleaning' pictures now. I've attached some for during the building process and after removal of the form. Much less clean! With the dome arch I waited 24h before removing the form, after which it was much harder to clean the inside. This time it went a lot easier with more fresh mortar after 6-8hrs. I hope yours is going to be fine too!
In the end UtahBeehiver is right of course: it's all going to get black, so no one is going to notice anyway

With respect to the vent opening: as long as it's larger than the chimney cross sectional area it should be OK. Mine might actually be too big, but I wanted to capture also a significant width of the barbecue area to ensure the smoke will also go in. Now I'll have to make a bigger/higher transition piece not to get the angles too flat.

[UtahBeehiver]

You are correct on the vent cross sectional should be larger than the chimney cross sectional area. FYI, a rectangular opening is not as efficient as a circular cross section so it is good you vent cross section is larger in area than the chimney.

[nlinva]

Ha, the "before cleaning" picture of the vent arch does make me feel a little better about my brickwork, though sadly my "after cleaning" is still closer to your "before cleaning" :-).

You do have a pretty wide opening in the vent. Since the bricks on the left and right edge are not quite vertical, it looks like it becomes even wider beyond the initial opening. I think that's common, but am not sure how it affects air flow. It could be a plus, as a place for smoke to collect rather than coming out the front, but it could also mean that air slows down before speeding up again, which might affect the draw. Or maybe these thoughts just show my complete ignorance in these matters :-)

[Toiletman]

After enjoying a small holiday I did manage to do a little work on the oven: I've added the fire-rope + kit on the back of the gallery and the permatex kit on the inside. The latter was challenging: the small gap doesn't allow the 'spout' to go into it deeply, so the process was rather messy. I should've taped it off beforehand to prevent the mess, as with the granite, but I found out while I had the kit open already, so I figured it might dry out and that I should clean up mechanically afterwards.
This turned out to be only partially possible, but in the end, as already mentioned it's all going to be mostly covered in soot, so I decided not to be too perfectionistic on it .
I took some final measurements of the chimney connection and covered the oven for winter. Although the weather has been really nice the last days I will only be able to do significant work after having the chimney connection on, and I don't think it's realistic I finish that before the weather will turn worse.

You do have a pretty wide opening in the vent. Since the bricks on the left and right edge are not quite vertical, it looks like it becomes even wider beyond the initial opening. I think that's common, but am not sure how it affects air flow. It could be a plus, as a place for smoke to collect rather than coming out the front, but it could also mean that air slows down before speeding up again, which might affect the draw. Or maybe these thoughts just show my complete ignorance in these matters :-)

You are right about this, although I'm not sure how much pressure loss will result from it. It might be in the similar order of magnitude as the improvement by rounding the corners. Anyway, by the time I'm making smoke it might be a fun area to investigate to see if the smoke indeed does 'recirculate' in the expansion chamber.

[Toiletman]

Forgot the pictures

[nlinva]

Yes, that Permatex stuff is quite sticky and hard to get on smoothly, especially in a narrow, hard-to-reach crack. I had the same problems you did, and mine looks quite messy; I might try to clean it up a bit, but as you say, it's really not going to matter much. I did learn my lesson and use tape for the silicone gasket between the front landing and the arch landing inside the vent arch. That worked very nicely.

I did actually try to tape where I put the Permatex Red, but the masking tape I had was not sticking to the firebrick surface. If I had to do it again (if I ever build another oven), I would make sure to get tape that sticks well.