My Precast build

[Cress]

Hi All

Special thanks to John the oven man for his help in getting started in the build

I decided to craft my own oven from the info from Forno Bravo and what i have learnt reading these forums here, thanks to all the good posts

I have the oven finished now i have been cooking pizza's roasts lasagna bread etc since august 2012! so six months of bliss!

OK onto the build

my first requirement was to be that it needs to be mobile if ever we move house i am taking this thing with me, and also if i want to go make pizza
at someone else's party i can!

so the first 4 pictures are the frame design the trolley has a removable top the angle iron frame lifts out of it to allow me to put the oven on a trailer etc


i hope the pictures attach

[Cress]

Re: My Precast build

Now
i have cut and inserted the insulation board its about 30mm thick
and put some mortar around the edges between the angle frame to lock them in place

the supports underneath are @ 300 centres

however if i was to do this again i would also lay either cement sheet or thin galvanized sheet under the insulation board for added security

[Laurentius]

Re: My Precast build

You should double your insulation.

[Cress]

Re: My Precast build

oven floor layout is 1050 mm inside diameter
notice i have turn the floor tiles to be at 45 degree's layout so the tools don't catch on the floor bricks

The mold was stuffed full of any rubbish i could find to save on sand,
i must admit the design of my chimney works extremely well the face of the front, i can still put my hand on it is just warm even after 2 hours of operation
i have seen people saying that they get burnt eyebrows etc from the heat coming out of the front!

Back to the mold
The face imitation brick was derived from cutting some weatherboards and using the rounded strip nailed to some chipboard i laid this out as best and rough as i could to imitate brick

i cut some stainless chimney about 150 mm long then sniped all around and bent the tags to embed into the concrete as shown

Sorry all i got excited at this point and forgot to take some pictures of the cement mixing stainless steel needle adding etc or the the final mold finished
more to come still

[Cress]

Re: My Precast build

You should double your insulation.

Yes i agree and that was the original plan,the supplier only had enough in stock for 1 layer
however

while the floor tiles are glowing red hot the under side is only just warm hardly noticeable so I am not loosing any heat really
and that board is 30mm so inch and a quarter thick

[Cress]

Re: My Precast build

The sand mold was covered in wet news paper the cement layered on by troweling till the desired thickness was achieved i have varying thickness through out the oven to aid i hope in heat distribution,

then the mold pulled off the front and the sand emptied out with all the rubbish etc and a work light used to warm the oven after 2 days of resting to help dry the oven out, i had used a piece of plaster board to make a temporary door to help keep the heat in while using the light.

[Cress]

Re: My Precast build

Ok the First FIRE

slow low fire as shown in picture for about 8 to 10 hours
then a bigger fire for another 10 Hours
till the oven was at operating temp

then i let it cool down and got it ready for some insulation only to be on top

[Cress]

Re: My Precast build

Insulation added i will use the oven like this for 6 months to dry it out then add the extra insulation and render see later pictures

[Cress]

Re: My Precast build

Some food from the oven the first pizza just a garlic and cheese

first roast
first loaf

and some pizza burning away inside the oven

Next how to rig the oven so it can be transported and render

[Cress]

Re: My Precast build

Now this oven needs to be mobile transporting it and keeping it tied down on a Ute or trailer is not going to be an easy task specially if you have a small accident this thing would go flying


so the design i come up with,
remove insulation
drill 4 holes through the steel frame and ceramic board close to the oven at = points for some all-thread rod

add chain to correct length to cross over at centre point and weld at that point
then weld off the nuts on the all-thread to stop them coming undone the underside nuts are then free to be tightened to a FIRM hold on the oven also notice how i have stripped some insulation down and tucked it under the chain links so they don't come into contact with the oven

The reason for using chain

it will have some give for expansion when the oven heats up and it will not transfer heat along the links very easily and the test confirmed i lost no heat down through the frame from the system at last firing

Little Bit more to come

[Cress]

Re: My Precast build

time to put insulation back on

then add double insulation and start chicken wire and render,stucco,

The door was made at a friends fabrication shop and had the sheet metal guys fold it for me i went to Bunnings got a broom stick handle and cut it as required, some stainless steel electrodes,some pieces to make handle extensions and welded it all up to make a door.

I may 1 day insulate the door, i have some board left over.

you may also notice a crack in the picture of the door dead center this was my fault not a casting fault. YOU have to take the chimney out before pushing it under the veranda in the dark and wonder what the hell belted you so hard on the HEAD!!!!!


so now the oven itself is finished just a little work to do on the frame and base to finish it off

please don't pick on my render effort it was my first attempt, i was going to finish it better then it is but due to other circumstances i did not get a chance to finish it off properly.

[Cress]

Re: My Precast build

So all told the build took me

4 days to first fire this includes the frame
and another day to do the chains and render

so here are some pictures of the spoils from last night
and a picture for anyone that is still in the cold weather

So thanks to all who shared designs, ideas, know how,
without Forno Bravo's help and plans this may never have happened

[Wayne73]

Re: My Precast build

great build and the pizza's look great too! but they will turn out better if you dont use the trays and just cook them straight on the oven floor

[Cress]

Re: My Precast build

great build and the pizza's look great too! but they will turn out better if you dont use the trays and just cook them straight on the oven floor

As of my attempts to go on the floor have resulted in burnt bottom raw top
I'm wondering what temperatures you guys have on the floor and on the dome

I can do it buy cooking three quarters of the time on the plate and then removing the pizza and dropping it directly on the floor

But my daughter see's any black she will say I burnt it

[mrchipster]

Re: My Precast build

As of my attempts to go on the floor have resulted in burnt bottom raw top
I'm wondering what temperatures you guys have on the floor and on the dome

I can do it buy cooking three quarters of the time on the plate and then removing the pizza and dropping it directly on the floor

But my daughter see's any black she will say I burnt it

Move the fire off to the side and let the oven neutralize for about 10-30 minutes. and the floor will cool a bit away from the fire, but I fear that if you are not getting the dome heat you desire your oven may still be a little damp.

Does the dome clear? if it does not your dome is not hot enough.

I typicaly see dome temps at 800-950 and floor similar. I do not see any live flames licking over the dome above the pizza just hot coals on the side in your photos, it is hard not to cook the top with live flames leaping half way across the dome, You can get some additional crisping by lifting the pizza to the top of the dome at the end of the cook to final it.

Chip