Seasoning Firewood

[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.   ;D



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.

[Tom]

I have used a pin type meter made by lignomat.  It is their cheapest model, mini-ligno, but does a good job for me. The factory prices are $110+ , but if you look around the internet,or look in the woodworking magazines, you will find this meter for $80 and sometimes as little as $60. 

It is plenty accurate enough for firewood and most air-drying situations.   It also impresses customers and gives you the excuse to return to a job and renew the contact.  "HI!  I just thought I'd stop by and see how your lumber was drying.  How have you been doing?"

[bandmiller2]

Sun and wind have great effect on drying wood.For years a friend and I cut all winter and stacked it under an overhanging roof south facing side of his stable, block painted dark brown.The winter sun and dry air would suck the moisture out in one week you could see the differance.In a couple of months the wood was so dry and hard it would ring when struck togather. Frank C.

[Warbird]

Saturday, a church group came over and helped me get the last 5 cord stacked.  The majority was already split to size.  Here are a few pics:

We have just over 2 cord of wood on the front porch:







We have about 5.5 cord of wood under the canopy:





And this is where the pile of split firewood sat for a few months.  You can see some birch, spruce, and cottonwood logs that I gathered a while ago.  Those are about ready to be bucked, split, and stacked.  Not sure if I'll get to this before the snow flies or not.





And here's the porch, shop, and canopy all in one shot:



Once the rain clears up, I'll be taking the back wall off that canopy and setting up a few fans to run all day, moving air across the stacks.  This wood is already fairly seasoned but I figure I may as well help it a long a bit more.  ;)

[Magicman]

What kind of heater do you have?  More than one?

[Warbird]

We have a large wood stove inside the house.



We also have an oil boiler in the shop that provides baseboard water heat for the shop and the house.  The only thing we heat in the house with it is the crawl space (usually 40 - 45° F), and the master bathroom (it is the farthest away from the wood stove).

I'm looking to redesign the whole boiler system.  Maybe pull it inside the house and put a small monitor heater in the shop or just a small wood stove.

[SwampDonkey]

I'm cold already just looking at that stacked softwood and tiny stove. :D I've got 9 cords of hard maple and beech stashed away and big old force air wood fired furnace beside an oil burner furnace. I'd rather open a window then be cold. :D :D

[Warbird]

Haha.  If you want to ship some of that hard maple over here, I'd surely love to burn it.  With hardwood like that, plus my wood stove, I could probably get 20 - 24 hour burn times.  We already get 12 - 14 burn times just with spruce.

Those forced air furnaces are nice but it is already so dry here, and I'm allergic to dist, so forced air can be hard on me.  Plus, the EPA came to town with their 'fine particulate regulations' and everyone with an outdoor furnace/boiler is getting the evil eye from the Federal government.   >:(

[SwampDonkey]

I feel sorry for anyone with allergies to smoke and dust, no laughing matter.



Wonder how this would fair under the EPA regs? :D :D

[doctorb]

Warbird

You are the first person on this thread to mention the use of fans to assist in outdoor wood drying.  Have you ever done any tests to see how much difference it makes?  I have considered it for my wood shed, which is about 50% open sided, and 50% walled with open windows.  Unfortnately, I have to stack row after row after row, like under your canopy, because of space constraints.  I try to leave some space between the rows, but it's not always possible.  I don't know how much air gets to the stacks against the walls, and I don't know if fans would help it much.  I have not, however, had a problem with this wood drying, as long as I give it at least 6 months.  Anybody else help move the air over their fuel?

Doctorb

[Warbird]

Hey doc.  I do not have any scientific numbers that prove air movement dries wood faster.  It just does.  As long as the the wood is split and you can get air to the ends of the wood, it will dry faster with air movement.

The best would be to have space between your stacks and just let the normal air movement assist the drying.  The wood you see under the white canopy in the pics above is from April of this year.  It has had quite a few months of seasoning but isn't as dry as I want.  Winter is close here, so I had to go ahead and get it under the canopy.  I removed the other side wall and set 2 oscillating fans (they are on stands) on high, blowing air into the stack.  Obviously, the front stack will dry the quickest but there are enough gaps in the stack that I can still feel a slight breeze at the back of the stack.

Another thing to consider with forcing air movement is the relative humidity.  In my experience, this method will be most efficient on relatively dry days.  If you are moving 98% RH air over the wood, it isn't going to be able to absorb much more moisture.  I'm sure it'll still help but dry air movement is the best.

The wood you see stacked on the porch is from last year and is super dry.  It's got ~1.5 years of seasoning and should see us through about a quarter of this winter.  So the wood under the canopy has more time. 

[Warbird]

I feel sorry for anyone with allergies to smoke and dust, no laughing matter.



Wonder how this would fair under the EPA regs? :D :D

Thankfully, I'm not allergic to smoke, just dust.  As for the smoke in the above pic, they'd have a field day with you!  They have this whole system where they will sit outside watching your smoke stack and taking pictures.  They have to be there for something like 15 - 30 minutes, at least.  They are measuring the opacity of the smoke and have to measure it a few times, to compensate for a fireshly stoked fire and such.

It's mostly a bunch of hogwash, IMO.  They recently got rid of the automobile I/M program here and the way I figure it, they needed to somehow replace that revenue.  Really ticks me off if I think about it too much.  Just more gov't control.

That being said, we do have a few folks who make a bad name for everyone else.  Those are the guys who will burn anything in an outdoor boiler.  Waste oil, junky wood, super green wood, etc.  Some guys are burning some truly noxious stuff and have generated many complaints.  And now we all get to deal with it, as neighbors can call and complain, sick the gov't on them, make life difficult, etc.

I'm all for the really bad folks being taken to task and made to burn somewhat responsibly, especially if their exhaust is choking their neighbors.  But the method they've chosen to take care of a small problem is just plain stupid because Fairbanks is in a bowl shaped valley and we have something called an 'inversion'.  What they've done will not fix the overall problem.   >:( >:(

[Tom]

I believe that my concern, with firewood stacked on the porch of my house, would be insects getting into the structure of the house.  It might be prudent to consider an application of insecticide to keep the egg-laying adults down.  Powder post beetles and termites would be a concern around here.

[Warbird]

Not too much concern of that, Tom.  We do have quite a few small spiders but they are mostly non-invasive and don't destroy anything.  Besides, they'll all be dead here real soon.  ;D

[Jeff]

 I had not read through this thread until tonight , but feel compelled to give you guys a little background info that may hep you understand we have a fellow here that really really does have a lot of experience and information in that shiny head of his. He's not about to say anything about that but I will because I'm proud as all get out to have him first as a friend and second as a member of the Forestry Forum.

Who?  Well the guy has really beenthere.  (LINK)

Just a quick google link

[Dean186]

Yesterday, here in Colorado it was 90 degrees with the relative humidity at 6% and winds at 10 plus mph all day.  On days like that, it doesn't take long for the pine I have stacked to dry out.  Of course that is the low humidity reading for the week, but it is much dryer here than in some parts of the county, so my splits and rounds do dry out pretty fast.

I get my rounds stacked this year for next year's wood.  So, the rounds set for almost a year and then split late spring.  The splits set over the summer and then burnt for our winter's heat.

I will get some photos to post.