Finally getting to building WFO in Calgary, Canada

[shanxk8]

Got one box of CF blanket installed this evening. It was 50 sq ft 1" thick, and I managed to get 2 layers over the oven.
I bought 3 boxes (150 sqft), so it looks that I can do 5" thick CF blanket, it maybe even 6" thick.
(I must have done something wrong with my math last year when calculating the amount needed)

I had only planned for 3" of CF blanket (hearth size limit), but find that the CF blanket is compressible . Could I compress the layers to make more blanket fit in the same thickness, or is the air within the blanket part of what provides the insulation?

[shanxk8]

Another question, if I am planning to stucco my vent arch up to the chimney, would it make sense to put on 1" or 2" of insulation on the arch itself?
I don't know how hot the arch might get and can't remember what I saw in other builds I've read.

[shanxk8]

Got a work lamp going in my dome last night, so I've started on my path to curing the oven. I was rather surprised that the top of the dome was registering in the 190°F range. Temperatures dropped down to 100 to 110°F and the floor was even cooler.
It will be interesting to see if the lamp has output to start any drying and increase the temps farther down the dome. By Friday I think I'll be moving on to briquettes.
I still only have the 2" of CF blanket at this point but plan to get to my (still undetermined) thickness before I move past briquettes.

[UtahBeehiver]

Rule of thermodynamics, heat rises. There is a lot of mass to be heated. I think your pcrete should be dry unless it got wet due to rain since you installed it over a year ago. Be patient with the curing, this is were I see a lot of builders want to hurry the curing process only to go too hot, to fast, and damage their ovens and all that hard work. You can cook something when you use the briquettes, dutch oven or tuscan grill............

[shanxk8]

I'm having in my mind to be patient, hopefully I keep to that. I plan to have the work lamp there til tomorrow (~2 days) then do briquettes on the next day or maybe 2. Then proceed to newspaper & small sticks for the ~300°F fires.

My pcrete probably has some moisture in it. I'd had the oven covered with tarps and plastic for most of the rain (all since dome complete) this year, but not the entire hearth slab, so there could be some moisture still in there. (I'll find out as I get to the real fires, as the work lamp isn't really heating the floor much - as one would expect)

Russell, as you used CF blanket, do you have input into my earlier question about compressing the CF blanket to fit in more layers (as I look to have excess of that insulation)?

[UtahBeehiver]

As far as compressing the blanket and effects, above my pay grade.

[shanxk8]

Got to 220°F at top and 130°F at the bottom row. I'm amazed that the lamp got the top to those temps.
gonna wait to at least tomorrow night to switch to briquettes

[SableSprings]

Got one box of CF blanket installed this evening. It was 50 sq ft 1" thick, and I managed to get 2 layers over the oven.
I bought 3 boxes (150 sqft), so it looks that I can do 5" thick CF blanket, it maybe even 6" thick.
(I must have done something wrong with my math last year when calculating the amount needed)

I had only planned for 3" of CF blanket (hearth size limit), but find that the CF blanket is compressible . Could I compress the layers to make more blanket fit in the same thickness, or is the air within the blanket part of what provides the insulation?

David, certainly a major portion of the insulation rating for ceramic batting is for the air spaces within the material. It's just like fiberglass insulation for a house...if you cram a piece of 6" thick insulation into a 2x4 framed wall space, the R value is diminished. Having 5" to 6" of insulation will be much more thermally effective than cramming/compressing the same amount material into a thinner layer. The better insulated your oven is, the quicker it will heat up and the longer it will retain heat. At least put in another layer getting you to the planned 3" thickness. I'd definitely go at least 4" of uncompressed blanket over your dome if you have it and can figure out the hearth problem you inferred. Five or six inches is probably on the side of diminishing returns (IMHO). You mention hearth size limits, but I strongly suspect you/we can figure out a way to accommodate the extra inches around the perimeter

Put aside excess batting for an insulated door or let other builders in the forum know you've got some extra for sale/barter. Again, since you've got it...use it as intended--uncompressed.

[shanxk8]

Thanks for the reply Mike. I guess I'll do 4" and then see where I sit. I'll have enough left for a dozen insulated doors!

[shanxk8]

Over the weekend transitioned from the work lamp to some lump charcoal to begin really curing the oven. After the rain let up, we got started and had a really nice photo op with the kids right as we were getting started
Got the oven up into the 260 or 270°F at the top of the dome.

[shanxk8]

Last night we had the first actual fire with kindling and small branches, getting the oven up to 350°F to 360°F at the top of the dome and 180°F to 200°F at the bottom course of bricks.

It was really relaxing (my wife described as mesmerizing) to sit out by the oven and watch the fire. Hopefully we can setup and enjoy a fire each night this week to keep the curing progressing.

[agrasyuk]

Time to kneed some dough )

[WarEagle90]

Oven turned out real nice, David. That certainly was a great photo with the kids, oven and the rainbow. Can't wait to start curing my oven, but I'm still a long way away from that point. In the meantime, I will sit back and enjoy your progress.

[Gulf]

I'm also having fun watching your progress and entusiasm. This is the fun stage. But, take your time. It is real easy to get too much wood on the fire at this stage which can lead to uneven heating of damp bricks and insulation. Here is another use for the charcoal. It gets hotter because it gets more o2 for combustion. A blast door or partially blocking the entry helps a bunch with this method.

[shanxk8]

Thanks for the nice comments and encouragement. It is definitely a fun part, but I quite enjoyed building the oven too.

Tonight was getting this between 400 to 450°F at top and 210 to 230°F at the bottom course. I found that my fires were kinda hard to keep consistent, too big then spread it out and the flame died. I think I will try for another day of fires at this temp range as the bottom brick temperature didn't increase much.
Also, this was the first day the inside of the dome really started to go black.

I will patiently not make any dough yet, then I won't be tempted to put the oven up to high temperature too fast to cook pizza.