Adelaide WFO Build

[david s]

Re: Adelaide WFO Build

Mick,
Your oven is still wet and needs more fires to dry it out. If you place some sheet plastic over it while firing you will see the condensation on the underside of it, indicatingbtherevis still moisture to get rid of. Also as you eliminate the moisture the oven will clear quicker and the fires easier to light. Firing a moist oven is a bitch, slow temp rise and a bit smokey.wait until it is perfectly dry before doing the outer shell, unless you want an outer shell with cracks in it.

Try using a little semolina (1/4 tsp) on the wooden peel before placing the base on it. This helps prevent it sticking, it acts like mini ball bearings to slide around on. Also beware of getting t sauce, o oil or pineapple juice on the peel. It all becomes really easy with a little practice.

We use a bread maker for dough all the time. You can do a batches and store them in the fridge or freezer too. One of the ideal things about it is that you can light the oven, throw on a batch of dough, go back to stoke the fire, open a beer and your fire will be ready at about the same time as your dough.
Good luck,
Dave

[vdubber]

Re: Adelaide WFO Build

G'day Dave.

You are spot on. After cooking tonight I noticed that the vermiculite insulation was damp in several patches, I guess this is the water / steam seeping through. I think I will leave the remainder of the insulation until the dome has dried out a little more. I was convinced that the series of small fires had dried it out but I guess I was wrong.

Whilst stoking it up this arvo, getting ready for the relies coming over I was looking for the carbon to burn off from the inside of the dome (I have read elsewhere that this is a good indication that things are up to temperature). What I noticed was that even after an hour and a half the dome was still black.

Ok. Something is obviously not right. I decide that my fire is obviously not big enough and add more wood. The fire starts cranking and the dome starts to clear. Yay.

As the fire progressed I moved it around the oven. I probably fed it about six or seven times over the course of a couple of hours. I started in the middle and then moved it side to side. When I stoked it right up I moved the fire to one edge, this seemed to draw a much better flame, in fact at one point the flames went right across the dome and just out of the door. I raked the coals across the base to heat things up before cooking. I then cleaned the base and left the fire hard up against one side for cooking the pizza.

Cooking pizza is easy. However, making pizza is something altogether different. I found it real easy to get the pizza stuck to the prep surface and impossible to get it on the peel. Then when I did get in on the peel, it stuck there too. Not good for pizza but earned a few laughs. There is definitely an art to be learned.

As the evening progressed I got the hang of things a little better. I ended up avoiding trying to make large thin bases and instead opted for smaller thicker ones. This made things a little easier.

We also used our bread maker to knock up the dough. This turned out not to be such a good idea. Great for a couple of pizzas but not for lots. Next time we plan to make it by hand in bulk.

Overall the evening was a great success. Lots to learn about using the oven, lots to learn about making pizza. What we did make tasted good, and apart from the early sticky pizza, most of what we made even looked like pizza.

So lessons learned...

Small thick pizzas.
Bigger fire (it almost seems like I should half fill the oven up with wood - does this sound right - what does everyone else do?)
Better prep area (need to get my work surface finished)
More pizza dough.

The oven held up very well. There does not appear to be any cracking and apart from the damp patches no noticeable changes. Tomorrow it's of to the local wholesalers to buy some bulk pizza flour and mozzarella.

Mick.

[cobblerdave]

Re: Adelaide WFO Build

Gudday Vduber
Yes I'm the first to admit it Ive cooked my first pizza after burning out the ply form work. Dome had cured and dried for a fortnight, dry hearth insulation used ...yep it was still scarey ...pizza tasted good.
However....I would be a little carefull from here on in you will still have water trapped in the mortar layer and have added quite a lot with the pearlite layer which is currently trapped in all those small spaces that makes your insulation work like it does. Add lots of heat you'll just turn that all to steam which could just as well damage your insulation and dome from the internall pressure.
Might I suggest leaving the dome unrendered for now to assist in allowing the water to escape. You have mentioned the wind and you have still the heat of summer there to speed things along.
I have had experience with wet ovens my oven was soaked as well during the brisbane floods (Rain only). It took quite a few low and slow fires to finally dry out. By the way when wet the oven will not get to pizza temp you'll find the top will clear but not the sides so its useless to cook in anyhow.



Wet soggy ovens produce wet soggy pizza!

Regards Dave

PS By the way I do like the round oven base Lots! suits the shape of a round oven I recon better than a square one

[vdubber]

Re: Adelaide WFO Build

I laid on the first layer of 'vermicrete' last night. Got to say, that stuff is not very sticky. Trying to get the stuff to stick about 8 inches up from the bottom is hardest. Anything higher and it sits there by it's own weight, anything lower and you can build it up and support it from the bottom.

I found that starting from the top and working down was easiest until you got to the 8 inch mark, then switching and working from the bottom up to finish it seemed to work.

The coat I added was about an inch thick, this equated to about half a (100ltr) bag. Still got a few coats to go yet.

Took this pic this morning.

Will wait until the weekend to put more coats on. Back to work today

[vdubber]

Re: Adelaide WFO Build

I lowered the outer arch by one course which helped a lot with the smoke. I think that the smoke is only when I first fire up. Once the fire gets going and the flue starts to draw it doesn't appear to be an issue. I think that with a deeper flue the issue might go away but with my limited space I couldn't go any deeper. A small compromise I guess.


My oven cracked immediately as I built it. The special fireclay / cement / lime / bricks sand combo made an excellent sticky clay-like mortar which made building the dome a breeze. The only issue, is being almost like potters clay, it shrank as it dried. The result was lots of little cracks on the larger joins.

I did not opt to shape every brick, only the top courses where gaps started to appear. This meant that there were quite large gaps at the rear of the bricks, which required a lot of mortar, this is where the cracks are.

Since firing it today, with ever increasing fires, no further cracks seem to have appeared.

However cracks or no cracks it does not appear to affect it's use. Not sure it will still be standing in 2000 years tho.

Here's the finished flue + stack

[brickie in oz]

Re: Adelaide WFO Build

the main issue I have found is that depending on which way the wind blows I sometimes get a bit of smoke coming out of the front.

It happen to all ovens Im sure.

Tonight we will test it as tomorrow the relies are coming over for pizza.

Ill be interested to see how it goes, the general consensus is to cure he hell out of the oven before a big fire to stop the oven from cracking....

[vdubber]

Re: Adelaide WFO Build

I may have misunderstood the time line of your posts or maybe the humidity in Aulstralia is a factor but, fire, already? wow

I let the dome dry out overnight and then lit a small fire this morning, I've kept a small fire going all day which is fun when you're still building the flue

Built it one day - used it the next.

I stoked it up a bit for lunch but it wasn't really hot enough to cook a 90 second pizza

The flue is finished and I'm just cementing in the chimney pot. I've let the dome cool this arvo so that I can render it.

Tonight we will test it as tomorrow the relies are coming over for pizza.

Here's some pics of lunchtimes results...

[Gulf]

Re: Adelaide WFO Build

I may have misunderstood the time line of your posts or maybe the humidity in Aulstralia is a factor but, fire, already? wow

[vdubber]

Re: Adelaide WFO Build

As Arthur Brown said...

"Fire!! Bring me Fire!!"

Hehehehe. Lit some small fires this morning whilst cutting the bricks for the arch. But whilst trying to figure out the flue I realised that somehow my arch had managed to rise up a course. Must have got carried away with laying bricks last night trying to use up the mortar.

Oddly enough, even with the higher arch it still draws really well, the main issue I have found is that depending on which way the wind blows I sometimes get a bit of smoke coming out of the front.

Anyhows, just stopped for a coffee and was excited enough to have to post about it .

Off to knock up some muck next.

Next stop lunchtime. I'm getting she who must be obeyed to knock up some pizza dough in the bread machine. Pizza for lunch.

[vdubber]

Re: Adelaide WFO Build

Finally got to lay some bricks today. I managed to get the dome up and some of the flue. I need to return the brick saw tomorrow morning so I will have to cut the remaining bricks with my grinder (I'm sure I will regret this - last time I cut bricks with a grinder I vowed never again - lol).

Need to get another bag or two of vermiculite to render the dome, and still have one counter top to pour, but apart from that I'm thinking pizza is on the menu tomorrow.

Still need to figure out how to fit my 'flue'. I sourced an old red chimney pot, now I just need to work out how it sits on top of the chimney 'stack'.

Here's some snaps of todays work.

[vdubber]

Re: Adelaide WFO Build

"eventually it will get tiled, but for the time being I thought why not."

Have you considered just grinding and polishing it ? Concrete counter tops can look very nice and are all but impervious to heat and to heavy pots being banged down. If you don't like the looks you can always tile it later.

Yes, but not sure how to do this. Is it easy?

[Neil2]

Re: Adelaide WFO Build

"eventually it will get tiled, but for the time being I thought why not."

Have you considered just grinding and polishing it ? Concrete counter tops can look very nice and are all but impervious to heat and to heavy pots being banged down. If you don't like the looks you can always tile it later.

[vdubber]

Re: Adelaide WFO Build

Didn't get the dome up today, mostly as there were no brick saws for hire.

Bit of trivia for anyone who's interested - All hire shops are required to electrically test and tag their equipment prior to each use. For some reason Bunnings do not employ anyone to do this at the weekend. Which means that stuff that's been hired on a Friday or Saturday is Tagged out until Monday, meaning that you can't hire it on Sunday. Funny thing is - I've been caught out by Bunnings the same way before.

I ended up hiring one from Kennings, but then wasted most of the morning trying to figure out how to fit the flue on the front of the oven. I made my base to the dimensions in Russel Jeavons book, 1500mm across, with an 1100mm dome. The difference is pretty much the width of a brick - which doesn't leave a lot of room for a flue.

I did end up deciding to lay the bricks flat, but not until I had laid them all out on end. My decision was partly made by not having enough bricks to finish the flue.

I took one brick out of the centre and substituted it with a red clay brick drilled out to accept the brick / dome gauge. I will swap it back once I've finished.

The flue was proving to be a bit of an issue, try as hard as I might, I could not figure out how to fit in on the base without needing more... erm... base. I eventually admitted defeat and decided to go get the book.

Even though there's not a lot of technical info in the book, there are some helpful line drawings. It was one of these that solved the problem for me. The archway bricks are cut (or at least the first row is shown this way) to match in with the first course. This allows the arch to sit further back towards the centre giving just enough room for the flue to fit. Problem solved.

Having fixed one issue, I then cut the bricks for the arch, trimmed the edge of the hearth and cut some of the bricks for the flue. One thing that I was deciding between was whether to build the outer wall up so that I could insulate the dome using dry vermiculite, or keep the dome shape and then insulate it with 'vermicrete'. For the time being I've decide to do that latter. Whilst I'm sure the rendered dome would probably not perform as well, it definitely has better aesthetics, plus I can always build the outer wall up down the track if I find that the oven does not hold its heat too well.

Building the flue up without the outer wall meant that the arch would probably require some additional support so I decided to make up another arch out of flatbar to help.

Hopefully I will get to actually lay some of the dome tomorrow.

Here's some pics...

[cobblerdave]

Re: Adelaide WFO Build

Dave, thanks of the reply.

I did take some time to try out the hearth bricks in both orientations, I definitely prefer on end.

Here's some pics...

Hoping to get the dome done tomorrow, but will see how I go.

Gudday
Consider using the hearth bricks the other way... not on there ends so you dont give the base to much termal mass. You'll find that most ovens take about 2 hours to get to "pizza temp" regardless of there size. Increasing the thermal mass takes more energy to heat yes the oven will take longer to cool down but do you really expend more time and wood to achieve this. Its much easier to increase the insulation to keep the heat in there and save on wood and time to pizza heat.
Your making great progress nice work

Regards Dave

[vdubber]

Re: Adelaide WFO Build

Dave, thanks of the reply.

Yes you are correct, I'm using the 'poor mans mix'

Thanks for the explanation about the lime, I will go get some tomorrow. As far as a membrane is concerned I've added a damp proof course in the brickwork. The slab will be under the level of the pavers and so the membrane will not work as it's basically below ground level.

Made good progress today. With the help of the better half we filled the base with hardcore and I finished a couple of courses that I didn't do last night as it was too dark. I then capped it off with a layer of mesh and concrete leaving enough of a gap for the vermicrete.

Unfortunately Thermal Cermaics was closed today so I ended up getting the vermiculite from the hydro shop around the corner. I bought 3 100ltr bags and ended up using two and half of them.

With the 'vermicrete' laid in, I set about making the formwork for the work surface. On the advice of the father-in-law (a builder) I set a sheet of concrete board as the base. The board is actually left in place. The board does not come to the edge of the 'slab' as the formwork tucks underneath so you cannot see it unless you peek underneath. It's not structural, it simply makes the formwork easier to make.

I then mixed up some concrete with some diggers black to set the work surface in. I decided to colour the surface as I had it spare - eventually it will get tiled, but for the time being I thought why not. Thats pretty much where I left it this evening.

I did take some time to try out the hearth bricks in both orientations, I definitely prefer on end.

Here's some pics...

Hoping to get the dome done tomorrow, but will see how I go.