36" build in heart of Europe, Czech Republic

[mrotter]

Insulation on. Btw, even this unfinished chimney IS DRAFTING smoke just fine. I was shocked to see that even this semi-done chimney works good. Smoke went through chimney and not front.

First fire: https://www.youtube.com/watch?v=63QX_ecgWSM

[david s]

It is best to do all of the drying fires before any outer render layers are applied. Otherwise any moisture left in will be much harder to eliminate. 1.5” (40mm) thick render is very thick, I only do mine 10-15 mm with random AR glass reinforcing fibres. The outer shell is only a weather protection and to stop damage to the insulation.

[mrotter]

It is best to do all of the drying fires before any outer render layers are applied. Otherwise any moisture left in will be much harder to eliminate. 1.5” (40mm) thick render is very thick, I only do mine 10-15 mm with random AR glass reinforcing fibres. The outer shell is only a weather protection and to stop damage to the insulation.

I did basic render yesterday. The brick and mortar was really really dried out, trust me, it stayed on hot sun for weeks, covered for rains.

As for render, maybe it is wording thing, but it is rather "concrete enclosure/shell", there will be one extra thin layer of silicone-based coloured render. I had some real bad luck yesterday as I was interrupted TWICE by rain and had to work hard to finish job, I ended in 23:59 MIDNIGHT!!! As for thickness, I believe I ended on average between 2-2.5 cm, some spots likely have thinner layer of concrete, around 1 cm maybe. If I used some special stucco material, I could likely go with thinner shell, but with pure concrete I feel the thickness is just about right. I also used reinforcing fibres, seems to work really nice.

As for moisture, during rendering I installed plug which can be opened at the very top of dom and I will have that opened during drying/curing process, but in overall, I do not believe I will need many extra curing fires. I will let it sit for two weeks now and likely apply concrete hardening solution (sprayed aerosol) to increase strength. Will provide photo soon, so far no cracking, my wife got order to keep the concrete covered and spray it with water each 2 hours.

Also, just ordered SS chimney system pieces.

[david s]

Spraying the surface infrequently is far less successful than keeping it constantly wet for damp curing. A superior method is to wrap the whole thing in cling wrap so it’s sealed up. Keeping this on for at least a week enhance the strength considerably.

[mrotter]

Spraying the surface infrequently is far less successful than keeping it constantly wet for damp curing. A superior method is to wrap the whole thing in cling wrap so it’s sealed up. Keeping this on for at least a week enhance the strength considerably.

Yes, I know, I have it covered all the time, especially in this hot weather.

[mrotter]

OK, I kept my concrete enclosure moist/covered for a week. I used reinforcing fibres, also top plug to let moist come out during curing/drying process. See photos.

Also, there is 15 mm gap between concrete shell and vent arch, to have trully lone-standing vent arch. This will be covered by heat resistant rope after top rendering is done.

[david s]

Great, you’re now ready to start slowly driving out the oven moisture. Try not to get too much flame impingement on the dome. The 7 fires in 7 days method with the fires getting progressively bigger works pretty well.

[mrotter]

Great, you’re now ready to start slowly driving out the oven moisture. Try not to get too much flame impingement on the dome. The 7 fires in 7 days method with the fires getting progressively bigger works pretty well.

Yes, I already made 1 very small fire, and one side test. I plan to light fires each day, for maybe 10 days. I still wait for some chimney parts which must be installed before I make larger fires, otherwise I risk damages to my terrace roof.

As a side test, I bought laser gun thermometer. I fired small fire on some extra firebricks and made some saussages on it. The fire was quite small, no big chunks of wood, it flamed for around 30 minutes. Then I measured temperature of bricks and I was just stoned. Top side of bricks was 200C, bottom side about 120C. I already smell the pizza guys.

[Honcho123]

Dobry, awesome oven

[mrotter]

OK, guys, after series of well-crafted curing fires, I obtained some dry hardwood and pushed oven to 500 C (1000 F) in all inner parts of the dome. Dome got way above 500 C, floor to 460 C and higher. Stainless steel chimney did magnificent job, no cracking so far anywhere. Baking long-baked meat/potatios in iron pot.

[mrotter]

https://imgur.com/a/YkezVwq

[flatfourfan]

Nice build......liking those temperatures!!!!