48" brick oven from Melbourne

[david s]

Re: 48" brick oven from Melbourne

G'day
Go with the charcoal, low and slow, the forno doesn't like them because possibly it concentrates the heat in a small floor space and could crack a large 50 mm tile. Put them in a tin and a couple of brick chips off the floor.
First Dry
And finally heat temper your oven.
Remember you have a faster build than most, you have a lot of moisture.
Its not DRIVING the moisture out its teasing it out.
Regards dave

What do you mean by "heat temper your oven"? The temperatures we fire to are not sufficient to sinter the materials, with the possible exception of the crown of the dome on the inside. There are two main problems, steam explosions and unequal expansion rates. Removing the water slowly to prevent steam explosions and trying to keep the temperatures fairly equal is the main thing. This can be done slowly and continuously or cycling back to ambient temps and starting again, allowing temperatures to equalise. It is the unequal temperature and hence unequal expansion which is the other problem.

[cobblerdave]

Re: 48" brick oven from Melbourne

G'day davids
Heating tempering like steel. Slowly taking it up in steps so the structure get even heat. Not trying to heat it in one go and introducing uneven stresses like you mention.
Regards dave

[david s]

Re: 48" brick oven from Melbourne

G'day davids
Heating tempering like steel. Slowly taking it up in steps so the structure get even heat. Not trying to heat it in one go and introducing uneven stresses like you mention.
Regards dave

Metals behave differently to refractory. You could be right, but I would be very doubtful if you could increase the strength of refractory by cycling the temperature at such low levels

[cobblerdave]

Re: 48" brick oven from Melbourne

G'day davids
I don't think its a case of increasing its strength rather of case of not testing those limits till it dry and ready.
Like you've said before , uneven stresses, and combination of steam are those real culprits for cracked ovens. They seem to survive a couple of cracks, but the owner/builders are always a bit disappointed.
It has been pleasing of late to not see that many ovens crack.
Regards dave

[david s]

Re: 48" brick oven from Melbourne

G'day davids
I don't think its a case of increasing its strength rather of case of not testing those limits till it dry and ready.
Like you've said before , I uneven stresses, and combination of steam are those real culprits for cracked ovens. They seem to survive a couple of cracks, but the owner/builders are always a bit disappointed.
It has been pleasing of late to not see that many ovens crack.
Regards dave

Ok, perhaps I misunderstood you. I thought the general meaning of "tempering" was to increase the strength of a material.
Still never heard of this method being used to increase the strength of refractory. Eg. You can refire pottery, say if you wanted to reglaze it, but it does not increase its strength or change its properties.

[wotavidone]

Re: 48" brick oven from Melbourne

No I don't think it is safe. You are likely to cook and melt your hose and potentially cause a gas accident. These burners are not designed for enclosed spaces and have no flame failure device. FB have asked members not to discuss the use of home or adapted burners for this reason. I do use one but don't discuss it here.

I support FB on this.
My father-in-law died in an LPG explosion in his garage. There is a LOT of energy in a gas cylinder and, if it happens to all get release at once, the damage is enormous.
Most people on this forum are fairly handy, or they wouldn't even be discussing building their own ovens, so they are probably quite capable of arranging something safely.
However, things can still go wrong. My father-in-law used all brand new gear, commercially available for the exact purpose he was using it for. This was no adaptation to another purpose.
This didn't save him, the shed, the fence, the cars, the neighbours' windows, the wall tiles over at the house, etc.
Wood's good.

[Dario]

Re: 48" brick oven from Melbourne

wotavidone

I support FB on this.
My father-in-law died in an LPG explosion in his garage.

Mate sorry to hear about your Father-in-law.

After long holiday and family commitments got some time to jump on and post a few pictures what's happening with my WFO Gentlements....
I've put ceramic blanket, chicken wire and went to get some Perlite to cover blanket with 20mm mix Perlite and GP Cement for the first layer ...It will happen tomorrow.

Dario

[oasiscdm]

Re: 48" brick oven from Melbourne

Dario

way to go looking good...get that flour yet

[Dario]

Re: 48" brick oven from Melbourne

Yes mate, got the flour today Caputo 25kg, $60 is that the one?
Covered blanket today with Perlite 20mm first layer this is the outcome of my WFO.
Any advice how should i finish my final coat, techique?
Final coat will be around 35mm thick and than i will roll on rustic acrylic render to waterproof.

Thank you
Dario

[oasiscdm]

Re: 48" brick oven from Melbourne

Yep that's the one. I didn't use perlite. But I am doing 40mm render layer over blanket, then using a new product to finish surface.

I used shiralite over my dome to lock brickwork. Then blanket.