WFO CNR Build - Darwin

[UtahBeehiver]

You do not need to buttress a full arch An arch with vertical side walls "and" a heavy chimney (ie brick, rock, etc) or ovens with full soldier courses are candidates for buttressing. I do not see a need to buttress yours.

[cobblerdave]

G’day
The internal brick shell of my oven is pretty much isolated from the outside world and pretty much apart from heating/cooling only has to deal with gravity. The outer arch entrance on this oven is planned to be insulated from the oven entrance brick by high temp rope insulation. So it’s basically a single skinned structure. The loads aren’t going to be static. The stainless steel chimney is like a big lever and open to the next force that comes along ie. children.
You build them they will climb them. Mines always been a kid magnet and still is. The kids next door have already snuck over and climbed mine!
So if it’s external double skinned I say.
regards Dave

[terratree]

Thanks Guys,

A bit of progress to show, outer arch complete.

Vent is now 15.7 " x 6.5 " (400 x 165). Hope its not too big.

Outer arch top keystones worked out well, meant i didnt have to add another brick here to initiate level.

Is it ok to start curing this oven , given the amount of rain were likely to see ? It is under cover, but the humidity is thru the roof. Was thinking heat beads, wood is too wet anyway. I have no vermicrete to contend with, so only moisture held in the bricks..

J

[terratree]

Will be putting the FB blanket directly over the IFB's tomorrow, and then some fine aviary wire over that to hold it and the render in place. I think the smaller gauge wire was preferred over chook wire ?

I have searched but cannot find the ratio/mix for the 1st/2nd/3rd coats of render/stucco, or is this store bought ? If so, what type ?

Thanks

J

[terratree]

With cyclone looming overhead, managed to get blanket and mesh screwed to IFB's.

Some progress on the vent. Will no doubt have cracks where Ive fixed the outer arch to the inner (10 -2 oclock). RemInder of the outer arch is floating,

Stuck a spotlight inside the dome, to prevent additional moisture ingress. I fear its way too wet to start curing.

[Steady]

Did the cyclone hit your area, everyone ok?

[terratree]

Cyclone was a fizzer Steady.

The spotlight idea was excellent - got to around 60 deg c.

2 weeks of that, and its time to slowly ramp up the curing.
5 x heatbeads are in.

Coupla pics

[terratree]

Few recent pics to share.

Old spare house tiles did the trick (hid the truth)

Max oven temp 550 degc, and still haven't had the dome clear. Outside temp on CF blanket gets to about 50degc. About 2-3 hours heat up time, but going steady.

Was amazed to see how much water was pushed out of the dome during the cure. Certainly reinforces the go slow approach.

Dome now renderered after a few weeks of cooking and under the week long cling wrap cure.

Very happy with the oven. Confident to get at least 5 days of cooking from 1 firing (with a door). Temp door kinda burst into flames after a few pizzas. Time to make proper.

Thanks to all forum members who have shared their builds and to all the regulars that consistently help!!!

[Chach]

Congrats! Looks very nice. You will enjoy using the oven for sure. Be safe.

Ricky

[Yokosuka dweller]

So you finished - the oven looks real good terratree - and the render very smooth. Good job. I gotto get mine finished also soon, but now that I can cook with it, progress has slowed down.

What mix did you use for rendering above the insulation? And how long you waited after sponge/troweling (?) it to wrap with cling wrap? I've seen DavidS mention this a few times, but I'm not exactly sure of the stucco mix and the procedure with cling wrap. Because if you throw it on too soon, it'll leave scars in the render isn't it? Are you planning to water proof the dome? Not that you need it with the nice roofing up top. Cheers!

[terratree]

Hi Yokosuka D, outer render was 4:1:1 (S:L:C), but i also added equal amounts of a store bought render that contained fibres (for flexibility). From Bunnings here in Oz - as in pic. Depth of cover would be about 15- 20 mm.

As soon as render was applied, i kept it quite damp with a spray bottle set on fine mist until it was not moving to the touch. Wrapped the whole thing in cling wrap, as per DavidS. I then sprayed that cling wrap until saturated and covered the dome again with the builders plastic that goes under cement slabs. Left it for about 10 days, but kept spraying water mist on top of the cling wrap daily - this did keep the whole environment moist.

Yes, I will waterproof the dome with a tile pointing product but only after many fires, and in our dry season (Jul)

I still havent made a door, (yours looks good) but will start shortly.

Cheers

J

[terratree]

Looks a bit different when dried

Will give it a heavy run over the next 2 weeks

[cobblerdave]

G’day
that wouldn’t be a dingo trap on the top of the entrance would it?

[terratree]

Well spotted Dave, an old (de-armed) Lanes Ace brand, in fact.

[terratree]

Just a quick follow up on waterproofing the dome.

Many thanks to david s for his advice on using diluted tile pointing for a final tough, waterproof coat.

I used a typical Bunnings product, Dunlop Tile Pointing, as in pic.

I have since fired the oven a few times and have had no cracks in this product. Ratio i used was more like 30-40% water, and that was just thin enough to apply with a broad brush (forget the roller idea)

Stir the water in thoroughly until the white glue like stuff gets mixed back in to the render, then go for it. I only managed 2 coats, with a thickness of about 3-4mm.