Seasoning Firewood

[doctorb]

Thanks beenthere and Swamp-

Yep - this old dog can learn new tricks.  Maybe I should separate some of my wood from an identical tree and follow the inside moisture content through the winter months, just for fun.  thanks again for the info.  enlightening.

Doctorb

[pineywoods]

pineywoods
Hate to be the one to break the news to you, but it is a myth. 
The old timer didn't really know.
But if one believes it works, then it at least feels good.

That may be the truth, but it gives me a plausible excuse to put off bucking and splitting for a couple of weeks 

[Magicman]

Plus the leaves fall off and handling the limbs is easier.  I just hook the JD to the tree and drag it whole to the bucking and splitting place.   

[John Mc]

pineywoods
Hate to be the one to break the news to you, but it is a myth.  
The old timer didn't really know.
But if one believes it works, then it at least feels good.

I'm curious how you know this. I've been tempted to do a trial with some beech, but haven't gotten around to it yet. I was going to drop one tree and leave the limbs and leaves on, another of the same size and limb it, then come back and buck and split it a month later (should be plenty of time for the leaves to dry out), and measure the MC at some of the fresh splits. I was also thinking of bucking a few rounds off the butt of these at the time they were dropped, then splitting and stacking them single row, in the sun, cut ends aimed into the wind (which is my current preferred method for fastest drying). My bet is that the stuff that is cut and split right away will beat both of the tree-length ones easily, but I'm curious how the "leaves on" versus limbed trees will compare.

[doctorb]

John Mc - right on target.

I agree that a little scientific investigation would help us decide whether the myth can hold water or not.  (bad reference on this topic).  Unfortunately, it may not be a simple comparison.  Do you think that the mc of the entire tree is affected by leaving the limbs and leaves on, or will it only effect the upper limbs?

I agree with J Mc.  I think that anything cut, split and stacked will dry out faster than wood (tree) that sits for a month, intact, only to then go through the same process.  It is a reasonable question.  If John Mc and I are wrong, there's going to be felled trees lying all over this country waiting to be cut and split at a later time.

I am going to take down several black locust trees that are arching over my neighbors driveway.  I may perform the same type of experiment.  Makes things interesting.

Doctorb

[pineywoods]

My knowledge on the subject is purely un-scientific, from 2 sources. I have a neighbor who is well up in the 90's, bod all worn out, but his mind is sharper than mine, plus he has a few years experience. He swears that the leaves will suck most of the moisture from the trunk. Second is my experience with bug killed pine. Pine beetles eat the cambium layer starting at the stump level, effective girdling the tree just as surely as a chain saw. Magicman will probably back me on this, you ain't sawed a dry log until you saw a bug killed pine. I don't have a moisture meter, using one to test the idea would be interesting.

[HOOF-ER]

Not wanting to argue , this is what I have been told from an old logger. He was logging an island and they had to float the logs out. The logs kept sinking so to eliminate the loss of logs they dropped the trees with leaves on and left them lay for several weeks and no more sinking logs. I would assume that meant the logs lost considerable more moisture from this method.

[doctorb]

What may be an ideal experiment is to take down a green tree that forks fairly close to the ground.  Measure the moisture content of the trunk of both of the forks.  Assuming they are identical, cut, split, and stack one side, leaving the other half untouched for a month.  Cut, split and stack the second "delayed" half.  Take measurements of the mc from each of the 2 halves at the time the "delayed" half is cut (one month from felling the tree), and then monthly for a few months.

This should allow wood from the same tree, treated with 2 different methods, to have the mc tested and compard fairly.  sounds like a project for doctorb.  I gotta go find the right tree.


doctorb

[SwampDonkey]

It's possible some species could sink when green or sit in the water for a period that they got denser than water (62.4 lbs/ft³ @40-70°F). Some of the oaks, locust, osage, shagbark, persimmon, eastern hophornbeam.

[John Mc]

I would not be surprised if the "leaves on" method does pull a bit of moisture out of the trunk as compared to limbing the tree but otherwise leaving the trunk intact. If for some reason I know I'm going to have time to drop them, but not have time to buck and split, sometimes I leave the limbs & leaves on. I figure it can't hurt. But often I take them off anyway -- especially if I have a bunch of trees to drop in one area. The tangled mess they leave if I don't limb more or less as I go is just not worth the hassle of dealing with later.

I would also not be surprised if limbs & leaves on vs limbed drying effectiveness varies considerably with species.

[Magicman]

Well, I dropped these trees July 29th.  This is what they look like exactly one month later.  Sure, the leaves are dead, and I have no idea what effect that had on the wood.  I knew that I wanted them down for firewood and I did not have time to buck them up (and still don't) but at least they are not still sucking moisture out of the ground.  I would think that the leaves continue to draw some moisture, at least for a few days, but who knows   I don't, and really don't care.  It's just easier when the leaves fall off.  I'll just run over the small limbs with the bushhog and grind them up.   
 


July 29, 2010
 


August 29, 2010

[RSteiner]

I have also heard that "story" about leaving the tree lay with the leaves on will dry the wood faster.  I have no emperical evidence that it made a "big" difference in the length of time it takes to dry out the wood.  I think that after the leaves begin to wilt they are not sucking up any more moisture, which takes only a few days.

One thing I have noticed is that trees cut in the dead of winter don't have as much moisture in the wood as trees cut in the spring and summer months.  I try to cut most of my firewood then.  I have also noticed that wood left tree length does not dry much at all.  I at least try to buck every thing to stove length and pile it until I can get it out of the woods and split it as soon as possible.

Randy

[Warbird]

Does one of our sponsors sell one of these moisture meters you guys are talking about?  I'd like to pick one up if it isn't too expensive.

As for drying in the winter...  maybe it's just because it gets so dry here during the frigidly cold winters, but my firewood seems to dry just fine during winter.  Clothes that aren't sopping wet also dry out quickly in frigid temperatures.  However, if you were to put a soaking wet rag in a pile out on the porch, it would simply turn to ice.  Perhaps surface area and level of saturation plays into whether things will dry or simply freeze during winter?

How does freeze drying work, anyway?

[doctorb]

Warbird-
I looked through the list of FF sponsors and I did not see any any manufacturer of moisture meters.  I could be wrong as I was comparing it to a googled list of available devices.

Mine is made by Extech.  There are many different models and manufacturers from which to choose.  As in many things, you can spend just about as much money as you would like.  Seem to run from $35 up to several hundred.

I am always amazed in winter when snow melt turns to a thin sheen of water on the black tarmack during a sunny day, and the water on the road generally evaporates off,  leaving a dry road.  Certainly temperature has something to do with this.  If water could not be absorbed into the air in winter, then we'd have black ice everywhere every winter's night!

Doctorb

[SwampDonkey]

One thing I have noticed is that trees cut in the dead of winter don't have as much moisture in the wood as trees cut in the spring and summer months.

If that were the case, than every pulp mill buying on tonnage in the country, would be dropping the price of wood purchased in summer. Paying for all the extra water they can't use.

[SwampDonkey]

Warbird-
I am always amazed in winter when snow melt turns to a thin sheen of water on the black tarmack during a sunny day, and the water on the road generally evaporates off,  leaving a dry road.  Certainly temperature has something to do with this.  If water could not be absorbed into the air in winter, then we'd have black ice everywhere every winter's night!

Doctorb

Salt on the road acts as a catalyst to melt snow in freezing temps, but that only works down to a certain degree, any colder and the salt is useless unless the sun is warm enough to raise the temp.


When wood takes on moisture in the cell wall, it makes a hydrogen bond and gives off energy doing it. This is called "heat of wetting". So, to reverse it energy has to be applied to remove the hydrogen bonding. This applies to "bound water" and not the free water within cell lumins. I think free water can become bound and taken up by the cell wall if the energy being applied to dry the wood is lost or reduced as the atmosphere around the wood equalizes with the wood structure. Also, drying is not a uniform process because wood structure is not perfect and lots of other variables like thickness of the material and so on. Wood is hygroscopic, so it wants to take on water if it has extra capacity to do so. It can naturally loose water to equalize with the atmosphere. Call this equilibrium moisture content, which varies by climate. The trouble with relative humidity by itself, is it gives no indication of how much water vapour is in the air for wood to equalize with. A figure of say 80 % with an air temperature of 40 has a lot less vapour than at a temp of 100 degrees at 80 % RH.

[Stan snider]

"A figure of say 80 % with an air temperature of 40 has a lot less vapour than at a temp of 100 degrees at 80 % RH"   This fact is what makes a cold front a likely time for some rain to fall.   I think the best gauge of drying potential from day to day is the difference in day max temps and night low temps.  If you have ever done any sandblasting this will be a critical part of planning whether to blast or wait till later. Less than20 degrees swing spells trouble. Stan

[Mooseherder]

I looked through the list of FF sponsors and I did not see any any manufacturer of moisture meters.  I could be wrong as I was comparing it to a googled list of available devices.

Doctorb

Bailey's sells a couple of them and they're a long time sponsor. 

[doctorb]

Mooseherder - thanks for the correction.  I was looking at manufacturers, not retailers, and missed that.  Happy to promote FF sponsors.

Good stuff on the temp / relative humidity gradient.  Very instructive.

Doctorb

[John Mc]

One of the reasons wood does not dry as well in the winter (at least in climates that have a "real" winter) is that the moisture does not move very well through the wood when it is below freezing. So any drying tends to be surface drying, and not as much gets drawn out from the interior of the wood.

The occasional warm day, or a sunny day may warm up the wood a bit and let the moisture flow, but this does not go too much below the surface unless it stays sunny and warmer for an extended period.