Paul's 42" WFO - Canberra Australia

[Muscats]

After reading many threads on the forum and absorbing as much of the wisdom and experience to be found here, I have finally made a start on my oven and thought I start a thread so I can ask the inevitable question I will have along the way and to share some pics with everyone.

As the thread title says I am building a 42" (1100mm) Pompeii oven in Canberra, Australia. My plan is to lower the dome height by using an indespensible tool with the center point set lower the the oven floor.

Paul

[Muscats]

Re: Paul's 42" WFO - Canberra Australia

Some pics showing the location in our entertaining area, markout, excavation, reo.

[nissanneill]

Re: Paul's 42" WFO - Canberra Australia

Keep it going an you will be enjoying pizzas, breads and roasts for Christmas.

Cheers

Neill

PS Keep the pics coming, we all enjoy them!

[Muscats]

Re: Paul's 42" WFO - Canberra Australia

I have poured the slab now and hope to make a start on the stand on the weekend.

A few more pics, note the neighbours in the background of the second shot.

[nissanneill]

Re: Paul's 42" WFO - Canberra Australia

Peskie little critters, aren't they!
I just delivered some colorbond roofing to a friend up in the Adelaide Hills and he has asked if I know suitable fencing contractors to install a 2metre chain wire fence around their house/garden plots just to keep the kangaroos out and save their fruit and veggies.
Wonderful animals, inquisitive, no brains or road sense, (as I have hit numerous ones with the 4wd out in the country), but wonderful symbols for Australia.
I have included an article in our Sunday paper from last week just for the visitors.
Cheers

Neill

[Muscats]

Re: Paul's 42" WFO - Canberra Australia

Yeh;

problem is with all the rain over the last year they have had a population explosion and we are getting around 200 going through our paddocks everyday. You can see how green it is at the moment and all the females with joeys ready to leave the pouch, you can bet they all already have another one in there as well. I wonder how roo would go in the WFO?

[nissanneill]

Re: Paul's 42" WFO - Canberra Australia

I wonder how roo would go in the WFO?

There's really only one way to find out!
Go for it but might I also suggest trying some smoked roo!
You can also use the oven for this, especially with a ready supply at hand.

Neill

[Muscats]

Re: Paul's 42" WFO - Canberra Australia

So my plan is to make a low dome 42" Pompeii, aiming for 17 inch dome height by lowing the center point of the Indespensible Tool, see attached.
Does anyone see any problems with this approach?

[tinaloven]

Re: Paul's 42" WFO - Canberra Australia

g'day Paul

looks good so far. Im encountering the same dilemma. Id like to go for a shallow dome although some issues arrises as the overall strength diminishes as the dome gets lower. After some research. A parabola design is the strongest but as its more of a triangle its not very heat effective. So there is a trade of in the two designs. Ellipse is better at thermal mass but weaker dome Parabola is stronger but takes for fuel to heat and maintain. I guess thats why they go for the semi circle although very strong without any weight on it but brick ovens are load bearing so where do we stand at the design of the dome. Im in the same boat as you which way do I go? Im actually building one in Queanbeyan myself.

I've built my dome gauge with measurements so if I go for a shallow dome I can change the angle exactly with it.

my dome is large it's 1280mm about 50 inches. I went for a big build a) we have a big family and when we have get togethers its a very large gathering 2. we live on acreage with plenty of fuel. 3 I'm aiming to turn it into a business where I can produce breads, sun dried tomatoes etc and sell at various markets.

Im waiting on my insulation board and cooking tiles. (ordered from "Johnny the Oven Man") who has the best prices of all oven building material I found in Australia he 's in Melbourne and he delivers. So Ive marked out and cut my bricks which will lay on top of insulation then 300x300 cooking tiles.

Yes over engineered but better than under I always say.

But basically Im stuck on the dome, I want my oven to last 2000years (I wish)

[brickie in oz]

Re: Paul's 42" WFO - Canberra Australia

no brains or road sense,

But so much more sensible that Emus....

[Muscats]

Re: Paul's 42" WFO - Canberra Australia

But so much more sensible that Emus....

Ain't that the thruth, I remember my sister's car getting hit by Emus on two separate occassions when driving to Burke from Sydney. Now she wasn't hitting them they where running out of the bush and hitting her car side on and man do they do some damage.

[Muscats]

Re: Paul's 42" WFO - Canberra Australia

g'day Paul

looks good so far. Im encountering the same dilemma. Id like to go for a shallow dome although some issues arrises as the overall strength diminishes as the dome gets lower. After some research. A parabola design is the strongest but as its more of a triangle its not very heat effective. So there is a trade of in the two designs. Ellipse is better at thermal mass but weaker dome Parabola is stronger but takes for fuel to heat and maintain. I guess thats why they go for the semi circle although very strong without any weight on it but brick ovens are load bearing so where do we stand at the design of the dome. Im in the same boat as you which way do I go? Im actually building one in Queanbeyan myself.

Wow, Queanbeyan. We moved from Queanbeyan to Burra about 18 months ago, where about do you live?

The idea if I lower the point for the tool means I should still get a perfect semi circular dome just not the full half its like slicing through the circle above the middle so that the distance from the slice to the top of the circle is less than the radius.

I've built my dome gauge with measurements so if I go for a shallow dome I can change the angle exactly with it.

Nice shots of the tool you have made, very neat. I have had a go at one already but I think I will make another. my plan to get the attachment point for the tool lower than the cooking floor is to remove a floor tile and the insulation bricks beneath it, but I have worked out that the tool will need two bends in it to get it to reach over the floor level. The first tool I made has the right angle piece attached square to the second piece of the tool i.e. after the second bend, but I have realised that the right angle piece needs to be square to the line of the tool irrespective of the bends in it, if that makes sense. As I am typing this I am thinking it might be easier to just remove all of the floor tiles and most of the insulation bricks and use a straight tool to build the dome and then replace the insualtion and floor tiles

[brickie in oz]

Re: Paul's 42" WFO - Canberra Australia

they where running out of the bush

Ive had them run 300M from the other side of the road just to be in the way...

[tinaloven]

Re: Paul's 42" WFO - Canberra Australia

Live in Greenleigh,

One thing you will always have is that slight hight difference to the width difference (around a inch or so) due to what type of swivel rotation axis point you fix to the floor. Ideally a door hinge which is obviously flatter then place a bearing so it can turn underneath. I found thats too much mucking about and got a $4.30 swivel wheel from bunnings which fits my 30mm steel tubing snugly. I used a square 25mm tube that slides inside from the pictures you can see I cut an old tap measure and glued it to the 30mm and measured from the inside edge of the "L" steel bracket ($5.00 from bunnings) which had to be grinded flush as the inner "L" was rounded. Measured to the centre of the swivel. Then cut the sides of both tubings so I could slot in a bolt and nut to maintain exact length plus my cousin wants to build a smaller oven when Im done so he can adjust the tool. I spayed it rust proof black so it doesn't seize up in the future.

The L bracket and tube piping and swill all have to be dead centre.

I can see what your saying I think in lowering the tool so it compensates for this. I think that its only a few cm's difference in my case that it wont matter to much plus any extra height greater than a semi circle turns into a parabola which is stronger. Im going for strength built to last rather than the shallower dome.

Someone did post a great link to informed article about dome and arches at
Auroville Earth Institute, training courses, workshops on Vaults, Arches, Domes(VAD), stabilized rammed earth walls, compressed earth blocks, vaulted structures, compressed stabilised earth blocks, rammed earth.
http://www.earth-auroville.com/maint...uctures-en.pdf
http://www.earth-auroville.com/maint...notions-en.pdf

In semi circle domes, their main concern is the horizontal thrust needs to be in the middle third of your brick dome to be strong.

The thickness of your dome walls needs to be in relation to the internal span. The thickness needs to be the span divined by 5 i.e. T = Span/5. so if you have a 42" oven span your brick dome should be 8.4" thick. Thats how I read it and if someone would like to confirm or check this.

PS. we have roo's that eat our back yard lawn and I wonder at the possibility of kangaroo toped pizza mmm yummy! They are looking at the oven curiously and I again wonder if they know my thoughts?

[Muscats]

Re: Paul's 42" WFO - Canberra Australia

Oh Greenleigh, nice area.
Sounds like we have both been to bunnings buying the same things. I got a swivel wheel there too, but i must have bought the a smaller one going on the price. I also bought a Post Stirup (the sought used for pergolas) to use for the right angel, it comes with a piece of pipe welded at right angles in the center.

I like the idea of the slot in the tubing, did you cut that with an angle grinder? I might copy your design and go with square tubing I have been trying to work with round but given that my tool will have bends in it I am finding it difficult to make the tool remain straight (i.e. on the same plane).

8.4" seems quite thick, thats almost a full brick? I suppose we get quite a bit of leaway with the holding strength of the mortar.

By the way, I took a trip to Sydney to Field Furnace to get my material.