Northern Ontario oven build

[Shawnr]

I will be cutting the backer board back to accommodate the bricks for the tunnel. Thanks for the input. I will check out david s' builds.

Regards,

[david s]

The problem with a brick flue gallery is that it is extremely heavy, meaning high thermal mass creating a heat sink effect which can sap some heat from the dome. In addition it is extremely difficult to make compound curves with brick units. Casting a flue gallery with a castable refractory allows a far thinner and therefore lighter gallery as well as making the compound curves easily. Another alternative is to have a stainless gallery fabricated.

Here's a link to a brick arch repair incorporating a cast in situ flue gallery that you might find useful.
https://community.fornobravo.com/for...723#post435723

[david s]

oops, my apologies, I didn't look back at your build. I see now you already have the gallery and chimney already built. Generally bends should not be any flatter than 45 degrees or the draw will be reduced. As Russell has already pointed out, if the oven is new it will smoke a fair bit, particularly on light up or if the chamber contains too much fuel. You can also increase the draw a bit by extending the flue pipe above your roof. However, if it were mine I'd be just trying continuing to use it as the smoke out the front will reduce as the oven dries out. Also start with smaller fires.

[Shawnr]

Thanks for the reply david s

When I mounted the cast vent to the dome, I put some fireplace rope insulation between the two so it should be mostly thermally isolated. I will be trying a 24" extension to the chimney. It, initially, does smoke like a very starved fire so perhaps a greater draw will cause more air into the oven. I am wondering if the smoke is drawn out the vent more, it will cause a better air flow into the oven....maybe I am overly optimistic.

Once the fire was going (I was evaluating it last night....had to do a test and all...;-) ) the smoke died down, but when I added a log, the black smoke increased out the front again. It does not smoke all the time, just when I start the fire or add wood. I do like the chimney in the center, for the doghouse style I built, but if I were to do it again, not sure I would do the squirrel tail design up the dome or just go straight up over the tunnel. I think the path I created over the dome reduced the area of the flow, despite my calculations and efforts to not reduce it below the area of a 6" pipe.So, I think I caused a slight restriction there.

But, at the end of the day, I am loving it. Gotta admit, I am getting pizza'd out though, so gave a pie to the neighbors last night and waved a boat in from the lake to share some.

Total fun! I probably never would have started such a project without this forum so Thank You to all who contribute and Forno Bravo for hosting it!

Cheers,

[david s]

Don’t be in a rush to alter anything until you’ve had plenty more fires. Sometimes a new and wet oven is so smoky the fire actually goes out. There is way more moisture in it than you’d think and it takes way longer than you’d think to eliminate it. I’m sure you’ll notice improvement without having to do anything. But I also think you are correct about more restriction with your set up than a straight vertical pipe.