Karangi Dudes Barrel Bread Oven

[Karangi Dude]

After a long illness I have finally started to build a bread oven for our new WFO and cooking classes,
The oven needs to be built first before we close in the 9metres x 5metres room, only the entrance of the oven will be in the kitchen with rest of the oven outside.
With the floor height 500mm of the ground we planned a platform to sit on 4 concrete pads to take the 1.75 ton oven
The oven will be a barrel / vault oven measuring 1060mm wide by 1295mm long, wall and hearth thickness of 115mm and fully insulated
First we cleared the area and measured out the footings each at 400x400x400mm I made up a frame and marked out the position of each of the footings then dug the holes and put the frame back down before pouring the concrete

[Karangi Dude]

After having the platform fabricated it was time to move it into place (it was very heavy we had to skid it on steel bars) next was to level it and bolt it down.
Then I set out the base insulation form and poured 90mm of vermiculite No3 with Portland cement at 7/1
I then gave it two weeks to bake in the hot sun we have had a very hot summer with weeks of 40 plus degrees centigrade (104 plus Fahrenheit)

[UtahBeehiver]

It is really great to have you back and especially to see you are building a new cooking oven. BTW, those who do not know KD, he is one of our pioneers on the forum, great cook and always willing to help our members.

[Karangi Dude]

Thanks Russell, for your kind words.
The oven design has been floating around in my head for some time now, it should be a versatile oven with similar features to an igloo but with a more usable floor space

Cheers Doug

[david s]

Your new build is going well. During a visit to Tasmania this time last year, we came across a wood fired bakery in Ross, a lovely historic town. They rebuilt the old low, large radius vault oven and have documented it in an interesting , but long, story.. Their oven is fired daily, cooking bread, pies and pastries daily and probably never really cools down. A great place to visit.

http://www.rossbakery.com.au/booklet.pdf

http://www.rossbakery.com.au/

[cobblerdave]

G’day
Welcome back for a 3rd oven!
Your a deadset legend Doug.
Dont think I’d have another in me except using someone else’s back!
watching with interest
Regards Dave

[Karangi Dude]

Thanks David s,

The Ross Bakery was a good read, it amazes me how much thermal mass goes into those Scotch ovens, I visited a bakery at Dorrigo on the way from Coffs Harbour to Armidale NSW where they have a twin oven set up that they use 6 days a week the owner was kind with his time and took me on a tour of the bakery he said the temperature never gets below 100c (it would take a long time to cool as there is about 30 tons of sand below and above the ovens) here are some pics I am sorry they are a bit blurry.

Here is Scotch Oven Australia facebook page https://www.facebook.com/SandyBogusisArt/

[Karangi Dude]

Hey Cobbler Dave,

Good to hear from you, yes another oven, I didn't think that I would build so many ovens but that's just the way it has turned out.
Looks like I will be building another oven for my son an igloo on a metal stand so he can take it with him if he moves but first I have to finish this one and then complete the build around it

Cheers Doug

[Karangi Dude]

Vermiculite all cured next I laid down 50mm calcium silicate board then laid out the floor and cut in the hearth
Next I will the start laying bricks for the sides and back of the barrel

[Karangi Dude]

Before I started laying the bricks I ran the grinder over the hearth to level out any high areas then I laid the sides and back bricks

[UtahBeehiver]

Doug,

How big is this oven? Your old oven I remember being a 48" and this looks bigger. I see you are building it with lots of floor thermal mass so you must be planning on doing a lot ob baking. Looking forward to watching this bad boy get built.

[Karangi Dude]

Hi Russell,

The main cooking area is 45'' deep by 42.5'' wide it appears to be bigger probably because I have made it wider than normal, barrel / vault are normally longer than they are wide they also have deeper entrances
Aussie fire bricks are 9" x 4.5" x 3" I have laid the hearth with the bricks on there sides ( that's why they are not laid in herringbone ) giving me 4.5'' of thermal mass all over, walls, vault and hearth
My 48'' igloo oven had 3'' of hearth mass so I have bumped this up a bit for this oven it should give me more retained heat for multiple batches when baking, I am thinking of offering a bread baking class as well as the normal cooking classes, just an idea at the moment as the bread classes would need to run over two days so that may not work to well

Cheers Doug

[david s]

Hi Doug,

No doubt you have plans to brace the vault, but this advice from Daniel Rhodes, Kilns (acknowledged as the kiln builders bible) attached. While we are building ovens and not kilns that are designed to operate at double the temps we use, and therefore double the thermal expansion, the same principles apply. The larger the radius of the vault, the greater the side thrust.
I notice standing the floor bricks on edge, as well as increasing thermal mass, also eliminates a vulnerable horizontal mortar joint at the base of the walls, nice one.

Cheers,
Dave

[Karangi Dude]

Thanks David,

Interesting article by Daniel Rhodes it all makes good sense, yes I have planed on buttressing for the walls it will come in the form of insulation inside steel panels that I am having fabricated

Cheers Doug

[Karangi Dude]

Started making the form for the barrel, when I had the first panel of the form ready I used it as a temporary template to set out the bricks on the end wall.
Now I will continue to build the rest of the form ready to brick up the barrel ceiling, but before I do that I will get the first angle bricks cut and laid then work on the buttressing for the sides and back this will be fabricated folded steel