Building the mud oven. gather bricks for the base of the oven. layout for minimum gaps between bricks. We numbered the bricks to easily transfer. Fire bricks are best but they are $6 each so we went with old Canberra Reds (solid clay bricks)

mixing mud. we got this first batch wrong. too much clay and we didn't add any sand. but this first batch was only for the outside of base, to hold in the sand.

Making the border to old the sand base.

You can see it is quite wet and muddy, too much clay. it cracked really badly.

This will be filled in with a layer of road base and a layer of sand, then the bricks will sit on top of the sand.

layer the bricks carfully on the sand in the formation previously designed. the flat side must be facing up, and they must be very close together. Mix and match them to get a good fit.

laying the bricks closely together.

are you going to help or just take photos?

if you havn't placed the bricks correctly you will need to remove them and smooth the sand over again before putting the bricks back. things to ensure: there is enough room at the back for the wall and the front where the door will go.

the front hearth bricks hang over a little to make a little shelf and to enable ease of ash removal.

next is collect the sand to make the sand form. the dome must sit in the middle of the bricks. any kind of sand that holds its shape is fine.

getting enough sand.

begin the dome, compacting as you go.

the dome will the size of the inside of your oven.

still a bit small - add some more. the optimum size - height is 75% of the diameter.

Adding water stops the sand drying out and losing its shape.

fill in the gaps.

use some 2x4 to smooth the sand dome and compact it a little.

thing of beauty.

next mix the mud. the best mud mix is made up of clay - subsoil - and sharp sand. not too wet and well mixed - no lumps. We used the drop test where you roll up a ball of the mixture and compact it 50 times between your hands them drop from waist height. If its right is will deform but not break. I thought it was a very sandy mixture but this is what is required to avoid shrinkage and cracking. All the details are in this
great book .

mix mix mix. get all the helpers involved.

using a tarp to fold over the mud mix is an excellent way to achieve even consistancy.

more sand.

cover the sand dome with wet newspaper. this is to 1. keep the sand moist and 2. enable easy removal of sand after the dome is finished - so you don't scrape the mud away whilst removing the sand. I actually reckon you dont really need the paper and the wrinkles leave an impression on the inside of your oven.

digging some clay for the mud mix.

Begin to shape the clay around the sand form using your fist as a measure. go around and around in layers.

pressing down with fist to firm the mud and keep a square edge. Dont ever pressin to the sand form, push down against the mud already layed.

keep it consistant the whole way around.

note the consistancy of the mud. it is very sandy.

build it up.

cover even where the door will go - this gets cut out later.

need to mix some more mud.

nearly there.

smooth over and compact the mud by whacking it with a plank. If you are adding another layer then scratch the surface before adding next mud layer. other wise you can let this dry before cutting out the door.

stay tuned for next week when we fire her up.
