Planning a WFO build

[keefas@hotmail.co.uk]

hi all,

OK so i have decided that my next project is going to be wood fired oven! after reading through tons of post both on here and over at FB i think what i want to do is an igloo dome oven with a fairly lowish ceiling height for quicker warm up and faster cooking times (hopefully!) originally i liked the barrel vault ovens as it would be a cheaper and easier build however have been put off by some peoples opinions on them and longer heating up times.

OK so heres how i plan to do it hopefully depending on what people think as i have no experience at all when it comes to WFO's!
basically i am looking to keep costs down as much as possible due to my the impending arrival of my first child !! and also the weather over here in England's not great to say the least so probably not get as much usage as i would like! will external temps affect the internal temp at all? would it be possible to use all year round even in freezing conditions if i get wrapped up!!

i am pretty much going for the forno bravo Pompeii oven shape etc but the catch is instead of the brick dome i am going to cast the dome around a sand mould out of crushed firebrick, cement, and lime and possibly vermiculite if people think i need it in? I'm then going to bed the cast dome atop a course of firebricks or red clay brick upright for the first chain leaving out the inner door at the front so the height of the door would be at about 9 inch ( the top of the upright brick). i am hoping for a ceiling height of around 19 inch? or is that too high? i will the build a brick outer door with red brick and a chimney out of that as normal. also i could put a thermal blanket over the dome for extra insulation purposes if you think this is necessary then mesh and render over that! i think this oven would be visually appealing with a brick front arch brick chimney and a first course of brick around the dome and the rest painted cement render.

 the floor make up would be insulated conc with firebricks bedded on that or maybe a few corderite kiln shelves or i could maybe get hold of some granite but I'm not sure on that and how it performs under heat?

do you think a cast top dome will store and give out enough heat for neo pizza oven temps?

how is all this sounding am i going along the right lines? any help is appreciated as I'm going to start gathering materials probably in the new year.

sorry its a long post but wanted to try and get enough information across as possible! thanks in advance for any help i look forward to hearing everyones opinions!!

Keith

[Tscarborough]

No vermiculite in the dome casting itself.  You will probably also need to rethink and research your specific formula for the casting.  You don't say what diameter, but a 19" dome with a 9" door is a little out of optimal.  If you are going 40" or larger, I would suggest down to 15" height or even lower if all you will be cooking is pizza.

[keefas@hotmail.co.uk]

hi tom,

i was thinking around 36" internal and yea would definatly drop it to 15" if you think thats better a better height. would a 9" high door then be ok? yes mostly pizza maybe the odd chicken and loaf of bread when it has cooled off some if possible. how do you think the casted dome would fair? do you think i would need the thermal blanket?

cheers

ps also checked out your website earlier today some good info on there nice site!

[keefas@hotmail.co.uk]

could anyone point me in the right direction for a mix for the dome casting?? has anyone done this

[keefas@hotmail.co.uk]

ok there doesn't seem to be much love for the casting idea!! come on people give me your thoughts good or bad!!

there is a possibility i can source some reclaimed red clay brick now from a freind would this be a better option??

[Tscarborough]

I don't have any experience with casting refractory, so I can't speak to it.  Common solid red brick will generally work, although I would recommend firebrick for the floor at a minimum.

[shuboyje]

I've used castable for complex shapes, but not an entire oven. I think a properly done cast dome will perform every bit as well as a brick dome, but doing it right isn't cheap, and I get the feeling you are after bang for your buck.  To properly cast an oven you are going to need a quality multi part form(time and money), a vibration table or vibration apparatus of some sort(time + money), a quality commercial castable refractory(money++), and stainless needles(money++). 

In your situation I would probably build a quality base(like they describe in the Pompeii plans), insulate it well with board or vermicrete, put a firebrick floor on it, and then build a cob oven.  It is easy and cheap, but functional.  If the bug bites you and you think it will be worth your time and money to built a true masonry oven you simple demolish the cob dome and build a masonry dome on top of the stand, insulation, and oven floor you already have.

[keefas@hotmail.co.uk]

thanks jeff for the input, sounds like more work to make a decent cast job than it is to actually build the dome!! hmm i'll have to have a think now weigh up my options!