Finally getting to building WFO in Calgary, Canada

[shanxk8]

I think the smoke mainly comes out the front when the fire is barely burning or gone out/shouldering. When the fire is burning well the smoke all goes out the chimney like it should. We marveled at the layer between the smoke and clear air at the bottom of the oven when burning properly.

Also, I tried a top down fire (from firing your oven thread), it was shockingly effective. Why didn't boy scouts teach me that?

[shanxk8]

Here's the unit and outcome of the first meal cooked in the oven. It turned out delicious!
(I'll probably also post this in the what did you cook thread)

The third photo also shows a little of the progress that I've made in finishing details, arch underneath and brick around chimney.

[shanxk8]

Had another pretty good fire going last night. Cooking fire the night before was 300 to 350°F at the top of dome and 200-250°F at the bottom course. Had it there for a good 4 hours. Realized part way through i needed to remove the plastic sheet covering it to let out moisture

The fire last night got really hot (closer to 600°F at top of dome, hotter than i intended). I tried to keep the fire going in a ring around the oven to get more heat into the bottom. For most of the firing dome temp ranged from 450-550°F, bottom course varied in the the 200+ to 300°F and the middle of the floor even got over 300°F. It seems like i'm starting to get somewhere.

[shanxk8]

More firing last night, got up to 600 to 650°F at the top and constantly in 300 to 400°F at the bottom course . The floor was even up to 400 to 500°F. It doesn't seem like the heat was saturating the bricks yet after 1.5 hour fire at those temperatures. (Having not closed in oven I could read temp in low 100s on exterior surface of floor bricks)

It seems like it will need to be a big fire to get the dome to 700+. How big will that fire really need to be?
There was already pretty consistent flames licking along much of the dome to get the 600+ fire...

[UtahBeehiver]

If you still see moisture under the tarp as you fire it means there is still water in the brick/insulation. With each firing the oven will perform better. Again, it is not the time to rush the curing process and you can still cook something as well. The dome will clear (black soot burns off) in the 900 F range but you are not there yet in the curing process. You mention in a earlier post that the pcrete may have gotten wet as well. This area takes a long time to drive the water out.

[shanxk8]

A couple fires back i was seeing moisture under the tarp. I folded it back while firing for the last few (oops) as i thought i wanted it escaping rather than being trapped and going back into insulation and then bricks. Maybe i will leave it partway covering (half?) the oven so i can see if moisture is collecting.

I had thought that getting bricks up to the 5-600°F level means that i'd pushed most of the water out. Similarly, i'd thought the floor getting up to 4-500°F meant the pcrete was getting more dried out. (Maybe that is just the middle, but edges of pcrete have moisture -thus lower temps at outside of the floor.

This weekend i'll have to try for a longer duration burn to a 5-600°F temperature to get the oven saturated with heat, to see how that works right now.

[UtahBeehiver]

The tarp over the oven is an indicator that water is turning to steam if you see it during a fire, you can remove it periodically, then back on to check again. The inner surface may be reaching this temp but it does not mean the bottom is seeing the same temps. Like I mentioned it takes time to dry out floor pcrete.

[shanxk8]

So the last fire over the weekend was to cook another meal, chicken this time (yum!) After running for a while (hours) at 4-500°F and cooking, i'd planned to up the temperature a little higher than the last fire, so put in a couple more pieces of wood (~1.5" square, scraps of 2x4 halved lengthwise). When i went back later, the oven was over 900°F at the top and starting more than 1/2 clear. Not long after most of the dome was clearing, so i just left it and let it go. The floor was over 600°F also.

By the end the entire dome was clear, and inspectin gthe next day didn't see any cracks. My hope is that the upper dome that was built in 2018 was getting dry, and the lower dome built in 2017 had long since cured. Later this week, we may have to try getting up to the 8-900°F and get the floor over 700°F

[UtahBeehiver]

Dome is clearing nicely so your cure is working well plus you are getting some nice meals out of it.

[SableSprings]

So now comes the hard part...deciding whether to invite friends, relatives, or to just hunker down and enjoy the feast and wonderful bounty coming from your WFO. Nice build and looks like your cure is pretty much done, onward and upward

[shanxk8]

We got to cook the first pizzas in our oven two nights ago, and they were amazing.

Funny story, as my wife and father were home to start and tend to the fire while i was still at work. When I was leaving to go home I asked how it was going. I she told me the oven was about 600 degrees after 2 hours. I was worried the insulation got wet in a thunderstorm the day before. I measured the temp when I got home, 660. Fire was burning well and the dome was clearing. After a few minutes of worry, I realized my dad had the thermometer set to °C rather than °F. Top of the dome was a happy 1100+°F and the floor was 800+°F.

Cooking went smoother than I expected and the pizzas were delicious.
Thank you all for your help getting me this far. Lots still to do with cosmetic finishes but I've achieved the main goal!

[shanxk8]

Hello all, it has been a little while since i posted. In that time we've had a couple of successful pizza bakes. The most recent was 10 or eleven pizzas for a large family gathering.

Recent progress has been slower, with more insulation layers installed on the dome and some more brick work complete to cover the concrete blocks.

I've since run out of matching bricks, so have moved on to cutting the granite pieces to create the counter top before applying stucco to the dome.

The lastest pics were after the insulation and most of that brick work was done.

[shanxk8]

I have a couple questions for the forum, as I'm doing more thinking and less work on finishing the oven at the moment.

1. Insulated door, I need one now that we're trying to cook more frequently: trying to decide if metal door with CF blanket insulation inside should be made from stainless (original thought) or plain carbon steel. A friend familiar with wedding and metal suggests I actually build with bolts and no welds. So now I just need to figure out what material to buy.
How have people's metal doors held up when made with carbon vs stainless steel?

2. Have read about people using redgard. I unfortunately didn't put it under v-crete insulation, but am thinking it may be worthwhile to put on the remainder of the hearth to keep moisture from getting into concrete. Would this be worth it? I also had a thought, can redgard be used in between the layers of stucco, to help with waterproofing?

3. As I cut granite I am getting cuttings that I've started to collect. Could these cuttings be used instead of the colorants you'd but to mix with the epoxy? (This is for vertical joints between granite pieces)
Also, does anyone have suggestions on a good granite epoxy to use for joining countertops?

Thanks,
David

[UtahBeehiver]

1. Carbon steel has a K value (thermal conductivity) of 43 vs SS of 16, in perspective CaSi K value is 0.50-55. Aluminum has a substantially higher K value than even carbon steel. Some builders have been using wood to seal chambers at lower temps. Pro, lower thermal loss, will scorch at high temps. If your welder friend can weld SS (mig or tig) IMHO that is best. Get as thin as possible yet still hold shape. I found you can find scrap SS, from old BBQs or refrigerators.

2. no comment, never used

3. I would ask a counter top installer.

[shanxk8]

Thanks Russell. Do you have an idea how thin of SS or steel will still hold shape with high temps? I plan to make all from the same gauge (both sides and back facing the oven). I actually plan to make the front from wood, also bolted on such that it can be replaced if needed. My friend experience in welding indicated that shape issues would be more prevalent with welded due to cracking at corners due to thermal expansion/contraction. His suggestion is to create slots at the outer surface hole to allow for expansion/contraction of on surface relative to the other. I am leaning toward this option as it would allow me to build at home without welding.

From local home reno store there are options for 16G, 22G and 26G for carbon steel, more options for that & SS from the "metal supermarket". My thought is 26G is too thin, and my hope is 22G is adequate. I like the suggestion to search for scrap from BBQ or fridges, i may have to see what the internet (kijiji) contains before i go purchasing.

On #3, will have to follow-up with one. I was hoping someone that had worked with granite might have insight before i head there.