What fire wood should I not use? Firing Your Oven Discuss What fire wood should I not use? in the Oven Management forums; Thanks. I kind of suspected that to be the case. I have heard that the bark on birch can also ...

[rberg02]

Thanks. I kind of suspected that to be the case. I have heard that the bark on birch can also soot up chimneys. The Mugnaini ovens are also about 2" thick.

A little off-topic here and perhaps I should post this in another forum, but I'll give it a shot here first. I'm curious about the thermal efficiency of the floor in my Mugnaini oven. First a six-inch reinforced slab is poured. Over that goes six inches of dry sand topped with kraft paper and a final 3-inch slab on which the floor of the oven is set The dome is covered with a thermal blanket followed by a six-inch layer of insulating cement and topped with vermiculite (gable enclosure). How efficient is this setup and how does this compare with other ovens? Thanks.
Ron

[dmun]

Sand is a traditional insulator, but not a very efficient one. That said, it's better than nothing. Vermiculite/perlite concrete is much better, and the various engineered insulation boards are better still. I wonder why they would call for so much insulation on top, and so little underneath?

[CanuckJim]

Dmun has nailed it, as usual. From an efficiency standpoint, I'd have to say that the thicknesses and properties are almost backward. Cement slabs, even with so much sand, will wick heat from the floor, no matter what. It's recent common practice to use high heat ceramic insulation board under the oven floor to stop any heat sink developing in the slab.

Far as firewood goes, I built a AS oven, and I will burn just about anything to get the fire going, then switch to hardwoods like maple and oak. I have burned birch, but the bark is quite oily, so I tend to shy away from it when possible. Popular is fine. The one wood I will not burn is red pine because of the oily smoke and the lousy smell it produces.


Jim

[Mojoe]

This time of the year I'm burning anything dry... just wish the wife would quite asking me why the kitchen table is missing a leg.

[jwnorris]

Originally Posted by CanuckJim

<snip> Far as firewood goes, I built a AS oven, and I will burn just about anything to get the fire going, then switch to hardwoods like maple and oak. I have burned birch, but the bark is quite oily, so I tend to shy away from it when possible. Popular is fine. The one wood I will not burn is red pine because of the oily smoke and the lousy smell it produces.
Jim

We also need to remember the difference between a WFO and an AS bread oven. With the AS style the key is loading the mass with heat and then stabilizing the temperature.

With a WFO, we still cook with a live fire [at least some of the time] and the wood chosen has a greater effect on the final outcome of the food being cooked.

J W

[edschmidt]

If WFO stands for Wood Fired Oven both domes and AS ovens are WFO's and when cooking pizzas, and high temp. flat breads they are fired the same. Many domes have as much or more mass as AS ovens and will cook without fire as long or longer. In the real world the only difference I see is in the rediculous time required to bring the AS ovens to temp. My theory is that this is caused by

#1 The fire having a direct route up the vertical walls to the top of the oven and straight out the chimney

#2 The fact that this heat (being radient) is directional, therefore a parabala or dome has all area radiating to the center. The AS design has about 50% of the mass radiating heat at the other side and above the food.

I think I got off topic, Sorry.

[jwnorris]

Originally Posted by edschmidt

If WFO stands for Wood Fired Oven both domes and AS ovens are WFO's <snip>

I should have said DOME instead of WFO. I guess the point that I was trying to make is that most barrel shaped ovens seem to have more mass that most domes and therefore take more time to saturate with heat.

J W

[charlesaf3]

I would never burn pine, or any softwood, in anything but a campfire. Your chance of a destructive creosote fire is really high, which would pretty much destroy the oven.

Some dry wood will burn too hot, with possibilities of thermal shock, but I'm less worried about that.

[edschmidt]

I always burn pine to get my oven up to temp, then switch to hardwood at the end in order to get longer lasting hotter coals. As far as the creosote goes unless you never fully soak your oven beyond the 800 deg. range this shouldnt be a problem. It all gasifies and goes up leaves the oven at that point. I guess I cant make generalizations, but I do not worry about my oven being delicate, Ill toss in a snowball in order to add steam, and fire it soo hot that I cannot get within 3 feet of the thing with no ill effects (unless you count that one little fire, but that was easy to fit (next time will use non combustible roof sheeting)
Eddie

[charlesaf3]

creosote could offgas. It could also taint the food. I'd think the reasons its a no-no in a fireplace or would stove would apply even stronger to an oven, because of the flavor problem.

Chimney fires are hard on masonry. Granted, if its not attached to your house the risks aren't as risky.