36" WFO - Just outside Toronto, CANADA

[mrpubnight]

Closing off the dome was surprisingly harder than I had anticipated. A combination of the 1) excitement of getting it done, 2) being hunched over under my tent, and 3) large angles on two planes made for a difficult and trying exercise. When all was said and done it was extremely rewarding.

I decided to raise my cap on the outside (you can't really see it in the picture but it jets out about 1/2"). At the time I thought it looked 'interesting' but if doing it again I wouldn't do it. Despite the fact that no one will see it, I know it exists and [mostly due to aesthetics] I don't like it

I also forgot to drill a hole for my top thermometer. This made doing the work later a little more difficult because the cap is really 2 pieces and my drill bit was just a little short (mostly because of the excess 1/2" on the top cap).

[UtahBeehiver]

Congrats on plugging the dome. Always looks easier than actually doing it. Now that you have completed the dome, do be patient when you start curing, this is the point where we see a lot of builders get excited and fire too hot too fast and crack their ovens

[mrpubnight]

Thanks UtahBeehiver. Unfortunately that happened to me despite being careful and curing slowly - at least I thought it was slowly. I have a thread going in the "Firing your oven" channel (https://community.fornobravo.com/for...y-stage-curing).

I don't really know how it happened other than 1) not having done it slowly enough, 2) the manner in which I assembled my arch - poor mortaring, etc. I only used pine kindling and paper for the fires and progressed slowly (~100C / ~212F, ~150C / ~300F, ~200C / 400F...). In fact for my latest fire I was struggling to get up to 250C with that wood. I'm going to be try creating a more spread-out fire and get more surface area to the fire to see if that helps, otherwise I'm going to have to move to a harder wood in hopes that the higher energy density will help.

Now that it is cracked, I'm still not 100% what I'm going to so about it. There is no smoke coming out of it but as I mention in the other thread, my bigger concern is what will happen with the flue/chimney structure given that the expansion / contraction spans across the arch. How will the mortar for the chimney maintain any integrity if the bricks it attaches to are moving around?

Stephan

P.S. The temperature readings in the 2nd picture are roughly 230C (~450F) and 190C (~375F) at the top of the dome and in the back just above the soldier course respectively. This picture is during my 4th firing but the crack showed up after the 2nd firing and gets bigger with each subsequent higher burn.

[UtahBeehiver]

Ah, I keep forgetting that your thread is posting an already built oven.

[mrpubnight]

No problem. I guess since this is where I am currently at in my build, this thread would be considered live. I have to get my chimney, insulation and outer cladding done before winter hits, and ideally before the wet October weather comes as it just sucks to work when you can't feel your fingers.

So, my question re: the chimney is current. I'm still not 100% sure if I'm going to have a problem with it or if the expansion/contraction will stop once I'm cured and I guess more importantly if there are any scenarios where (if the movement will stop) if the movement may start again.

Thanks,
Stephan

[mrpubnight]

Well its been a while since I posted here. Thought I would give a quick update.

I finally got around to getting the outer arch done. I added some rebar to reinforce the vertical supports. I don't intend on having too much weight on the top of the arch (plan on using an single walled stove pipe) so I think the brick would have been good enough but this just adds a little extra reinforcement (I hope). I also managed to get my granite entryway put down too.

It is starting to feel moderately complete...if other builds on this forum are a guide, I only have about 1 or 2 years left

[mrpubnight]

Insulation has been added, lath wrapped, chimney stack started and first coat of mortar added. Certainly wish is wasn't almost November - that Arctic wind sure can take a bite out of the fingers.

The chimney took a little fiddling but finally got it mortared in and have the anchor plate (a 7" -> 6" reducer) installed. My mortaring upset me a little because I couldn't get it to black and since I applied it over multiple batches it doesn't match. No matter how much dye I added it just didn't get any darker, however, when I added the top chimney stack bricks, it seemed to take the dye better, or I just added a crap load and it finally went close to black. Need to decide how much I want the mortar between the rest of the bricks to match - may grind out a 1/4" and fill with mortar from a single batch or we may just file that feature under "character".

The insulation went on relatively smoothly. I purchased a 1.5" x 24" x 50' roll which left me just a little shy of getting 3" around the entire dome. Fortunately there was a pottery/kiln supplier that was open on the weekend I was doing this and sold insulation by the square foot - only needed an extra 14 sq ft. Got the job done and have a little left over for my door.

Attaching the lath was a real PITA for a couple reasons, 1) I didn't leave a lot of clearance between the dome and the fence which made my challenges with the lath more frustrating, 2) the lath just didn't want to play nice when I first started. Eventually I started getting it interwound with itself and it started getting easier and taking shape. It definitely took A LOT longer than I had assumed it would but I committed to spending a little more time on it and the shape so that mortaring the shell would be easier.

My first coat of mortar went on nice and smoothly. Not 100% sure what I want the outer coat of the dome to look like so I'm waiting to add the second coat - deciding between some sort of tile, or colored stucco, etc.

Added a photo of the chimney dry fitted too. May have to reconsider the placement or orientation of the thermometers as my wife can't stop seeing them as the eyes of a monster's face - and now that is all I see too - AARRGGHH!!!!