Northern Ontario oven build

[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.

[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]

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.

[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

[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,

[JRPizza]

I forgot you went with a cast chimney vent. The 13.5 inch "tunnel" that is common with brick ovens is a distance that allows a good "structural" build for the vent - enough opening to get airflow up the chimney and supporting structure to hold it all together. The 13.5 is from the dome arch to the front of the landing. You already have the vent part taken care of so the landing length/depth is whatever you want it to be. You probably want to extend it to the edge of your raised area, but you could go shorter than that if you want. david s uses his cast vents to make his landings relatively short - you should look at some of the ovens he has built for ideas.
I do wonder how hard it is going to be to build the upper part of any arch you do build with the backer board already installed. Do you have a plan for that?

[Shawnr]

I have cut a door out of steel to fit over the entry and another to fit into the entry. I planned on building a 2" door, using some left over ridgid insulation for the middle. To test the oven as mentioned above, I placed the bigger piece of steel in place, then held it in place with a fire brick. It was just to give me an idea of heat retention. I still need to figure out what we want to do with the tunnel. I don't think I like the look of the thinner bricks but was using up what I had left over. I may get the thicker ones to form the arch, although whatever it is built out of can be faced with something anyways. I do plan on stuccoing the house and top of the arch, just not the front of the arch. I like the looks of the brick face.

I have seen tunnels of various lengths. Is the 13.5" the most common? (brick and a half long) Does it make it harder to get things in and out? I can't seem to go near the stove without soot on my sleeve and I think with the tunnel complete, it will be even worse. Unless the planned chimney extension and complete tunnel makes airflow and draft better. Post #60 has a photo of the cast chimney adapter before the house went on.

Thank you

Shawn

[JRPizza]

I don't see where you have a door - have you made one yet? For any retained cooking you are going to need one as I don't think you can get enough heat into the bricks to overcome heat loss out the big opening. I started with a temp door made out of concrete board and even that really helped hold in the heat. Lots of ideas here for both weld and non-weld designs.

[Shawnr]

JRPizza good advice too. I noted last week that the oven was cooling already after a few pizzas and in the morning, it was only about 360 degrees. The interior was not totally cleared when I started cooking but the pizzas were great! However, if I hope to bake bread in the morning, I will need to get a deeper heat, I suppose. The thermocouples would be really good for this.

Thanks

[JRPizza]

Are you planning on drilling through all the way thru your bricks to the inside of the oven? If you are, you might want to consider doing it in two steps. I would first just install the probe (length permitting) so it reads the temperature on the outside of the bricks. Using an IR thermometer it is easy to get a reading of the inside temp. What I would find useful is knowing the brick OD temp so I could tell when the bricks were saturated with heat. There are times I want to do a quick firing and the dome gets cleared, but if I don't fire long enough the temperature falls off too fast and it's below where I want it before the meal is done. If I had an idea of the temp on the outside of the bricks I'd know how long to keep burning. If you didn't like that placement you could drill all the way through and get an interior reading. Short firings are the only reason I wish I had installed a measuring device against the outside of the heat mass.

[Shawnr]

Thank you for the response David I will go with the dome location you suggest.

[david s]

I think the best spot is about half way up the dome. You will need to make sure that the probe is long enough Toto reach all the way through the bricks/refractory and the insulation. The tip of the probe should protrude at least an inch inside the dome. Be careful that you don’t damage the porcelain sheath around the probe when installing it or when operating and cleaning the oven. Yes after some experience using your oven you won’t rely on it much.

[Shawnr]

Well, used the oven a couple of times over the winter. Pizzas gradually got ...less burnt... ;-)

We are now enjoying them though. There is definitely a steep learning curve to cooking in a wood fired oven.

Question...a friend gave me a Type K thermocouple from industry, quite a solid looking device so I am now wondering about installing it. The oven still sits as per the last photo so I would have to make a hole in the wall to install it in the dome or can easily install in the floor from underneath. I am learning to go by the look of the dome to judge cooking but just think that a sensor in the over would become is igeneral indicator. Also, a conversation starter. If you were to install only one thermocouple, where would you put it? And, extending into the dome, or terminating in the brick so as to measure brick temperature?

Or, if I recall correctly, those that have installed them seldom use them after a while.

Opinions ?

Thanks

Shawn

[Shawnr]

Roof is on. I have had several curing fires, although not always on successive days. I tried to up the temperatures (kind of averaging what my gun tells me) each day and on Sunday, the soot started clearing off the bricks. So I let it burn down and took advantage of the coals to cook something....all I had handy was burgers.

Today, I thawed some frozen pizzas which I don't really expect to be very good anyways..(as I read here somewhere too as an option to making nice pizzas to practice with) . Glad I did...burnt the first one....well done in 3 minutes, but then, burnt the second one (both thin crust) and then, after waiting a bit before inserting the next one, burnt the third one....

The pizzas were actually edible..... if one cut off the edge and did not mind a little over done,... but considering they were frozen ones, way better than from a kitchen oven! Now that I have done some cooking, I will go back to the cooking forums and get more tips/hints/direction. I think it will make more sense. I recall reading to heat the oven up, then let it cool down to around 800, then put pizzas in. Mine was less than that today. Oh well, I am sure it will get easier with practice.

I had to make a quick peel as I have not gotten to that yet so just cut a 1/4" piece of ply wood for today. Sacrificial pizzas cooked on a sacrificial wooden peel. Good fun!!

[Shawnr]

hillscp that I do not know. I just went to the lumber yard and said I needed metal studs so probably the usual residential ones. I don't know much about them (and that is why you won't see any close ups of the framing....... )