Suggested firewoods - are there any woods that one should NEVER use for firewood?

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What kind of cedar are people burning? Where I live we have lots of hardwoods so we don't usually bother burning cedars but there are a lot of those too. All the years I built and repaired fences in the middle of the woods on farms we didn't bother carrying fence posts with us. We just cut down cedars for that since they don't rot, they are almost like pressure treated. Some guys sell red cedar posts for up to $5 a piece for a 8 foot post about 6 inches in diameter, more for bigger ones. These are red cedars with the red, fragrant wood. I don't know if white cedars have the same rot resistent attributes. So is there any market for selling cedar fence posts anywhere else?
 
Size

Not trying to start a big discussion here, but...
I see that statement used on this forum often, and it ain't quite correct. Where it goes wrong is with the word "heat" instead of "energy". Einstein's famous equation E=MC[SUP]2[/SUP] states that any substances of equal mass contain the same stored energy, not heat. Mass is not the same thing as weight... for example, a square yard of concrete weighs less on the moon than it does on earth. Still, if we remain on earth, weight can be used to compare mass... on earth a pound of feathers have the same mass as a pound of steel, and both contain the same amount of stored energy.

When we burn wood we are using a chemical reaction to convert wood into something else, and that reaction releases some of that stored energy in the form of heat. Because a pound of cottonwood has the same mass as a pound of oak, if we could burn both, and trap all the heat energy released from both, it would be the same (in other words, if we had a 100-percent efficient appliance). But there ain't any such thing as a 100-percent efficient wood-burning appliance. A less-dense substance burns faster, or releases its energy faster... which means in a less than 100-percent efficient appliance a larger percentage of the heat energy will necessarily have to go out the flue.

Think of it this way... A pound of toilet paper holds the same stored energy as a pound of oak. For illustration purposes we will unroll that pound of toilet paper so it lays loose (even less dense). Now, take two wood stoves, put that pound of loose toilet paper in one and a pound of oak in the other... light them both. In just a few seconds the toilet paper will be consumed by fire in a massive hot flame, but you can lay your hand on the stove because near none of it was transferred to the steel. The oak is just getting started, and in a few minutes you won't be able to touch the stove without receiving a nasty burn.

It's the same thing, at a considerably lesser degree, with a less-dense wood; A somewhat smaller percentage of the heat produced will be available, or harnessed, to warm your butt. So even though a pound of cottonwood has the same potential heat value as a pound of oak, you would need a 100-percent efficient appliance to realize it. A high efficiency burn will do a better job of harnessing the heat from cottonwood... but at the same time it also does a better job of harnessing the heat from oak, although the gap gets smaller as efficiency increases.

But in the end, no matter how you slice it, you will harness more heat from a denser wood... you will get more heat from a pound of oak than you will from a pound of cottonwood.

I adjust my heat with size of piece that goes into the stove. I am just going to disagree with you on your last statement. Yes, if you split to the same size, different species will throw less or more heat "by the chunk", but if you split and burn with a bit more thought, using a much larger variety of sizes, plus adjust your stove feeding schedule appropriately, you can use the lesser species just as efficiently and it doesn't get into the ridiculoous range either.

Example, I burn a lot of the lesser tulip poplar and sweetgum. They are still great firewood sources, easy to harvest, and we have them in plenty. I adjust what size, how many, and frequency of loads determined by what demand I need any particular day or time of day, as the needs change all the time. I stack a really LARGE variety of sizes and species. No way are my stacks uniform in chunk size. This allows me *huge* flexibility in burn, and also what I can use from the woodlot again, huge flexibility.

My old heater is designed in such a way as it will throw heat with a single small stick, or filling it up, or anything in between, with whatever ya got, all you have to do is think about it, what you are trying to do. It is both a front and also top loader. Loading from the top I can put in quite a large chunk for a room heater type heater, or pack it with smaller rounds and splits (very rarely needed here, but it could be done if demand warranted it). On lesser demand times, load from the front, one or more pieces at a time. I even can time the heat output, say I want a little heat, then following that more heat, as in early evening to later on. Lesser species go on the bottom, throw a chunk or two of oak or whatever on top, it burns good that way and you can feel the heat output go up as soon as the bottom wood is mostly gone and the oak gets going later.

It's all in how you size and use your wood. There's a place for the lesser species in most scenarios.

And I burned the same way when I lived in New England, with plenty of double digits below zero temps to deal with, so it is not exactly a function of living up north and having a big heat demand for extended times, I still burned lesser species up there, and it worked fine. I like the "multifuel" method over the "just one species and one size" perfect wood approach.

Now I don't own or run any expensive EPA stove or boiler, so perhaps it is different, I will readily concede the point as I have no experience there, my only experiences are a variety over the years of plain jane old wood (cook) stoves and room heaters and some indoor plain furnaces, no water heating, just plain hot air. But, with those heaters, paying attention to load size and species versus demand and output desired is just as scientific a way to go about it as any other way, plus it results in cheaper and easier wood harvest, as you can take most anything and make good use from it.

Now ideally, a wood combustible appliance would be using very uniform fuel, such as pellets, with automatic controls, etc., to get the greatest efficiency, but once you start talking about harvesting your own and using various chunks of wood, efven similar size and the same species, then you just have to think a lot more, and it takes a bit more skull sweat to achieve close to that level efficiency. But, it can be done.

Beyond that, it would probably be better to build a pure designed wood gasifier and burn the gas in a real gas heater, if you really wanted maximum efficiency. I know the various designs of wood heaters I have seen posted here attempt to hit at that level, but there are pure gasifiers that work better.

I never have built one, although I did build and burn (test burns) a methane digester before. A wood gasifier would be interesting as you could run a cheap generator as well from the output, along with your heat. You need serious gas scrubbing though and like stainless steel plumbing and all sorts of expensive stuff.

different discussion sometime.
 
red is better

What kind of cedar are people burning? Where I live we have lots of hardwoods so we don't usually bother burning cedars but there are a lot of those too. All the years I built and repaired fences in the middle of the woods on farms we didn't bother carrying fence posts with us. We just cut down cedars for that since they don't rot, they are almost like pressure treated. Some guys sell red cedar posts for up to $5 a piece for a 8 foot post about 6 inches in diameter, more for bigger ones. These are red cedars with the red, fragrant wood. I don't know if white cedars have the same rot resistent attributes. So is there any market for selling cedar fence posts anywhere else?

The red stuff is great rot and bumble bee resistant wood, the white stuff the bees eat fast and it rots easier. been my experience anyway. Plus I have the fun of spraying down my boss's house and guest house all the time because he bought western white cedar logs to build them. Freeking bees eat their way in, then the wood peckers come over to get them. I wouldn't touch that stuff for structure building if I had access to the red. I have a little bridge over the ditch I made five years ago with red cedar I cut here, not a hint of rot or insect infestation yet.
 
Well, I'm not here to defend cottonwood because I seldom burn it inside my stove except to get the fire started. On the other hand, I would rather burn cottonwood than any conifer packed with pine tar. There are also hundreds of deer hunters, duck hunters, etc. who use it to heat cabins. Practically nothing gets a stove hotter faster than cottonwood, so it has its place. It's also perfect for campfires, especially when mixed with elm of any kind.

You can call cottonwood toilet paper all you want to. It brings a smile to my face. :msp_biggrin:

Meanwhile, this year I'll continue to burn in my stove my collection of walnut, ash, oak, locust, red elm, hackberry, and mulberry. These seem to work very well. Only mulberry throws sparks, but when used in good stove, that is a minor problem.

BTW, where were we on this thread before we started trashing cottonwood? I'm a bit lost. :popcorn:
 
The oak versus toilet paper analogy is interesting since it brings up a good point. You could pulp up some oak and then make it into toilet paper. Pound for pound, solid wood oak will beat the oak toilet paper as firewood even though they are both oak. You could say the same thing about oak logs versus oak kindling.

There's a lot more to it than the wood type obviously -- we also have to take into account what form it's in, surface area, moisture content, stove configuration/efficiency, ash production, etc. Sometimes it's hard to make "this wood" versus "that wood" comparisons in general when it can be a stretch even comparing the same wood!
 
Not trying to start a big discussion here, but...
I see that statement used on this forum often, and it ain't quite correct. Where it goes wrong is with the word "heat" instead of "energy". Einstein's famous equation E=MC[SUP]2[/SUP] states that any substances of equal mass contain the same stored energy, not heat. Mass is not the same thing as weight... for example, a square yard of concrete weighs less on the moon than it does on earth. Still, if we remain on earth, weight can be used to compare mass... on earth a pound of feathers have the same mass as a pound of steel, and both contain the same amount of stored energy.

I'm sure you are aware of this, but I just wanted to clarify that the famous Einstein equation shows the relationship that exists between matter and energy when it is converted fully from one to the other in a nuclear reaction. Not from a chemical reactions such as combustion. We see this type of mass to energy conversion in thermonuclear weapons and the fusion of Hydrogen atoms into Helium atoms in the core of the sun, not from burning wood (or any other basic exothermic chemical reaction) These types of reactions are governed by other laws of chemistry and thermodynamics. If you where to apply Einsteins equation to burning a pound of Oak (about .5 kg) then we should get approximately 43 trillion BTU's from 1 lb of oak. This equation does not apply to to this discussion.
 
Sorry for the above hijack, to answer the question, I will burn any species of wood in my CB (not poison ivy) even Willow, which I think is the worst firewood around here. But when it comes to burning inside the house I generally use quality hardwoods only.
 
Some times I cut monster grape vines, and even me the green wood burner need to let the grape vines season.
 
i was always told not to burn pine, but i see quite a few on here that say they burn it without issue. if i were to burn some pine is there anything special i would need to do with it or to watch for?

i burn quite a bit of pine (because it was free and cut for me) done this for years.

last summer i decided to clean my chimney....it's been years since i did it last. it wasn't worth my time to clean it. i ran the brush up and down and it removed alot of dust and the clay tiles were showing. i had almost zero creosote build up.

i believe where pine causes the most problems is in air tight stoves with metal chimneys. when you damper them down, they aren't hot, the gases rise up and the "cooler" metal chimney attracts the particles and creates a build up on the pipe.

just my theoretical opinion.
 
Well, I'm not here to defend cottonwood because I seldom burn it inside my stove except to get the fire started. On the other hand, I would rather burn cottonwood than any conifer packed with pine tar. There are also hundreds of deer hunters, duck hunters, etc. who use it to heat cabins. Practically nothing gets a stove hotter faster than cottonwood, so it has its place. It's also perfect for campfires, especially when mixed with elm of any kind.

You can call cottonwood toilet paper all you want to. It brings a smile to my face. :msp_biggrin:

Meanwhile, this year I'll continue to burn in my stove my collection of walnut, ash, oak, locust, red elm, hackberry, and mulberry. These seem to work very well. Only mulberry throws sparks, but when used in good stove, that is a minor problem.

BTW, where were we on this thread before we started trashing cottonwood? I'm a bit lost. :popcorn:

Another straw dog set up Ed--no "trashing" any species. Unless we can form the Cottonwood Anti-Defamation Ass. :jester:
The point was yours declaring the obvious that pound for pound all species give the same BTUs. We do understand density.

To elaborate: the toilet paper analogy is thusly ( not an E.B. White allowed word ) poundage. If you want to carry it to the Darwinian end then one pound of Charmin will give you the same BTUs as one pound of the beloved cottonwood. Expensive.

And you may well be lost. PM for a referral. BTW: what specialty "Doctor" are you ? Board certified Proctologist ? :bowdown::msp_smile:

Happy Thanksgiving !! Our deer season ends this week.
 
I agree with you on the splitting practice. For most woods anyway. There's probably some types that don't cure across the grains as well as they do through them, but mostly more exposure within seems to speed up the process. I've always wondered if the seasoning occurs more when the temperature changes form hot to cool, and warm to cool, than it does when it's mostly warm or hot. Refrigeration is a natural moisture thief, but exposure to it aids that process. So a woodshed might inhibit that when the temperature drops and rises in the cooler months.

Seasoning is simply the loss of moisture from the wood. Under what conditions do you think a bowl of water would most quickly evaporate? Answer that and I think you can figure it out.
 
Wait, I just want to go those 43 trillion btus, from a pound of oak. It would sure make collecting firewood easier. :)
 
Seasoning is simply the loss of moisture from the wood. Under what conditions do you think a bowl of water would most quickly evaporate? Answer that and I think you can figure it out.
Sorry, but don't quite get the connection. I mean, the bowl of water thing. Wood is a bit different
 
I've always wondered if the seasoning occurs more when the temperature changes form hot to cool, and warm to cool, than it does when it's mostly warm or hot.

Temperature and humidity variations absolutely affect drying rates. But it's hard to take advantage of them in the uncontrolled climate of the outdoors. I built my woodshed to use convection to help drying. If the wood is warm, cooler air rising around and through the rows will dry it fairly quickly. This seems to work best when the days are warm and the nights get cool.
 
Let's see here, I've burned a bunch of different woods over the years. I'll give a little of my preferences and opinions as I go:

Oak (Red, Burr, and White) top shelf stuff, if seasoned well.

Ironwood (Eastern Hophornbeam): HOT HOT HOT, the northern equal of hedge. Doesn't get big here, so it takes a lot of little trees to make a cord. That stack is reserved for brrr-frickin cold days in January and February, best to mix with a bit of faster burning wood, not at all good kindling.

Maple (Sugar, Red and Silver, also Box Elder (Manitoba Maple)) Huge swing in this family. Sugar maple is on par with oak, but seasons a bit faster. The red and silver are midgrade woods, but produce good heat. Burned mostly on weekends and mornings when I'm around to tend the stove. Box elder goes mostly to the firepit, but good to take the chill off in spring and fall.

Elm (Red, American, Siberian, etc) variable quality depending on condition when cut. Cut green, takes a while to season, but seems to heat a bit better than standing dead with the bark off, the usual condition I get them in), standing dead can be slightly punky before they tip over, and not a lot of heat in the punky stuff. Tops from dead standing are normally dry and solid, for someone looking to keep a stove fed straight from the saw, it's hard to beat.

Poplar/Cottonwood - grows back faster than you can burn it, and that's pretty fast. There's a reason match sticks are made from them, very good kindling and firestarters. Otherwise, day wood and spring/fall wood.

Birch (white/paper) Not quite oak, but if you get it processed before it starts to rot, very good wood.

Apple - nice wood in the stove, but really, save it for the grill.

Cherry - good on the grill too, or for woodworking, but I burn quite a bit, it's a common fenceline tree here, middle of the road heatingwise.

Pines/Spruce/Cedar/other softwoods - I don't get a lot of em, saved for firestarters or that snap crackle pop campfire from time to time.

The one wood not welcome back here is Buckeye/horse chestnut. If that's all OH can come up with to represent their state, I recommend everyone that lives in OH move out now. Nasty smelling, twisted wood won't stack after you ram the splitter through it, might possibly be an endothermic reaction when burned, and produces roughly 8 gallons of ash per 5 lb split. YUCK!
 
Sorry, but don't quite get the connection. I mean, the bowl of water thing. Wood is a bit different

How so? It's evaporation. The more surface area exposed to air the faster the evaporation process will be. Like you mentioned splitting is good even for smaller pieces. I agree that different species have different drying times, but that would seem to be related to their initial moisture content. What type of air has the most capacity to facilitate evaporation? Cool air with high humidity or warm air with low humidity? Add air movement to that and the evaporative effect becomes greater. You disagree with this theory?
 
How so? It's evaporation. The more surface area exposed to air the faster the evaporation process will be. Like you mentioned splitting is good even for smaller pieces. I agree that different species have different drying times, but that would seem to be related to their initial moisture content. What type of air has the most capacity to facilitate evaporation? Cool air with high humidity or warm air with low humidity? Add air movement to that and the evaporative effect becomes greater. You disagree with this theory?

Yes.....I think. I don't know whether different temperatures with the same humidity speed up or slow down the process of curing the wood. That is what I was musing. But the exposure thing....it seems as though no matter how many times I split a round, if it still has moisture in it when tossed in the fire, the hissing and moisture comes out the ends :smile2:
 
How so? It's evaporation. The more surface area exposed to air the faster the evaporation process will be. Like you mentioned splitting is good even for smaller pieces. I agree that different species have different drying times, but that would seem to be related to their initial moisture content. What type of air has the most capacity to facilitate evaporation? Cool air with high humidity or warm air with low humidity? Add air movement to that and the evaporative effect becomes greater. You disagree with this theory?

Right. Except that the climate doesn't always cooperate. Many places in the summer the air is humid and in winter it's dry. Of course, warm, dry weather with wind and full sun is optimum -- like, say, Albuquerque -- but we've got more big oaks here in Pennsylvania. I keep my stacks covered (an argument in itself) and find that a lot of good seasoning happens in winter when most of the moisture is frozen out of the air. Even ice cubes in your freezer will evaporate over time.
 
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