On 12/3/2022 at 11:30 PM, billyhill said:Thinking about trying something along the lines of this...
My entire life revolves around frugality. It's really more of a sickness than a forte. I've spend a good portion of my adult life trying to come up with a safe and inexpensive wood fired oven design. If an Ooni is presently outside your budget, then, I'm sorry to have to tell you that a wood fired oven is outside your budget as well. At least a safe one is.
That design you linked to... that thing is criminally dangerous. Poorly designed ovens like these can easily explode, sending red hot projectiles towards you, your family, and guests. It all boils down to the rapid expansion in volume when water converts into steam. Basically, any porous material- masonry, stone, mud, bricks, if these materials are the slightest bit damp, when you expose them to fire, the water inside them rapidly converts to steam, expands and BOOM!!!!!
https://www.youtube.com/watch?v=h5FMPWzG63A
What this means is that, for any wood fired oven, the inner chamber being exposed to the fire has to be kept BONE DRY. Since most inexpensive vapor barriers aren't suited to very high heat, this means that you have to have a layer of insulation between the oven chamber and your vapor barrier.
So the necessity for a dry oven chamber and the insulation/vapor barrier that entails is one thing that drives the price up.
The next thing is proper ceramic materials. Red clay bricks are cheap, but they are not suited for high temp applications AT ALL. This is why fire bricks exist- because when you exposed regular bricks to heat, they spall/flake- and the LAST thing you want to do is have a piece of your oven end up in your pizza. I have a chipped tooth from this very phenomenon. This means firebrick- for every exposed surface in your oven chamber. It also means expensive high temp refractory as mortar.
The next thing that drives up the price is internal real estate. You can't successfully bake a pizza with it practically touching the fire. You need a fire, and then a few inch buffer. This means that if you want to do Neapolitan pizzas, you really need at least a 30 inch internal diameter.
Another thing that you cannot skimp on is a chimney. The chimney is the thermodynamic foundation of a WFO. If the chimney doesn't draw air, you won't have proper combustion inside the oven chamber.
By the time you spend the money on the firebricks, the insulation, the vapor proofing, a structure to protect the oven from the elements and a chimney, you're probably talking the cost of at least three Oonis.
If that isn't enough to dissuade you, consider one more thing. The online communities (Forno Bravo, Pizzamaking.com) have a lot of helpful information, but they don't spoonfeed you everything you need to know. This involves a very extensive learning curve. I know a LOT of smart pizza people- both home and pros. I've never met a single person who nailed their first home built oven. Their second or third time around, sure, but never their first.
The Ooni Koda 12 is $400. It doesn't offer as much real estate as the $600 16, but, you can get some really good pies out of it. If you really want a wood fired oven, I'd save up and invest in a kit. If you shop carefully, I think a quality kit could be obtained for around $2K. But shop super carefully- a huge number of kits/plans have designs that are horrible for pizza. One rule of thumb to follow is that the inner height of the oven should never be much taller than the radius of the inner floor.
