oak drying time

I don't know if this helps BUT This weekend I cut down a few black oaks. Since they were big enough I cut one round 12 inches long and then made a 12 inch square . So I had 1 cubic foot of green oak. I then weighed the square and the weight was right on 64 lbs. Now come january I am going to cut a similar tree and do the same trial

mtarbert said:

I don't know if this helps BUT This weekend I cut down a few black oaks. Since they were big enough I cut one round 12 inches long and then made a 12 inch square . So I had 1 cubic foot of green oak. I then weighed the square and the weight was right on 64 lbs. Now come january I am going to cut a similar tree and do the same trial

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Man, no wonder I'm so beat tonight after hauling 18"+ diameter oak rounds cut to 20" long. More to haul tomorrow.

Shari

It does make a difference when you get up in the tree a bit. The leaves do pull some moisture out. The bottom is wet as heck always. Same with standing dead, the tips are always dryer...

I cut tree tops in the spring of 2009, tree's were dropped in Jan/Feb of that 2009. That wood is just about ready now, I figure two full summers on oak and it'll typically be pretty good.

I agree with this information on this site, does not make much difference when you cut the wood.
http://www.4information.com/trivia/tree-rise-spring/

Heres the reasoning, the tree stops feeding the leaves and the leaves pull the moisture out until they dry up. It may be different in different species but ash and oak by me have a noticable difference. Not sure about the shagbark hickorys. What we call choke cherry makes a big difference. The maple is the most obvious...

oldspark said:

I agree with this information on this site, does not make much difference when you cut the wood.
http://www.4information.com/trivia/tree-rise-spring/

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A British investigator found that in the fall the center of a tree is very wet, and the outer regions are comparatively dry, while in the spring this condition is reversed. He concluded that if we desire to make our language conform with the fact we should not say that the sap is up in the spring and down in the fall, but that it is out (near the bark) in the spring and in (toward the center) in the fall. Analysis shows that pieces of wood cut from trees in the winter sometimes have a moisture content just as high or even higher than pieces cut in the spring or early summer.

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So the water content may be roughly the same, but late-cut wood is drier on the outside. Since it's a known fact that wood dries across the grain lines by diffusion along a moisture gradient (wetter on the inside than on the outside), seems to me it will dry faster if that gradient is already established. Therefore, late-cut wood should dry faster, even though it has the same starting moisture content as spring-cut wood. For the past 25 years, the majority of my wood has been cut in the fall or winter, and I don't notice the drying times to be as long as some claim is necessary.

I've also noticed that standing dead wood with no bark and a thin layer of punk on the outside is almost always pretty dry on the inside. I attribute this to the punk layer's ability to wick out moisture faster and therefore creating an even larger diffusion gradient. Of course, as that punk layer gets thicker, it takes too long for the outside to dry between rains and the rot progresses inward. This is an observation I have made mostly on smaller diameter trees I encounter in the woods. It may not hold true for large diameter trunks, so as always, YMMV.

Folklore or not I guess it kinda makes sense but they say never cut down a tree when a full moon is scheduled as that is when the most water is when tides are highest and the most water is in the tree =p

burntime said:

Heres the reasoning, the tree stops feeding the leaves and the leaves pull the moisture out until they dry up.

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That seems reasonable, but it doesn't account for how transpiration really works. Leaves are actually pretty waterproof. The shiny upper surface (cuticle) is covered with a waxy substance that prevents water from entering or exiting. Almost all of the transpiration occurs through stomata, which are like little valves that cover the underside of the leaf. These valves open and close as the trees transpiration needs vary. When the leaves start to die, they stop functioning and remain closed, so no water can escape via evaporation. Further, the petiole (leaf stem) shrinks as the leaf starts to die and the inner passages of the stem no longer carry water. Without these control mechanisms, trees would dry out in short order during a long dry spell.

Battenkiller said:

So the water content may be roughly the same, but late-cut wood is drier on the outside. Since it's a known fact that wood dries across the grain lines by diffusion along a moisture gradient (wetter on the inside than on the outside), seems to me it will dry faster if that gradient is already established. Therefore, late-cut wood should dry faster, even though it has the same starting moisture content as spring-cut wood. For the past 25 years, the majority of my wood has been cut in the fall or winter, and I don't notice the drying times to be as long as some claim is necessary.

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While you aren't exactly wrong, I think you may be leaving a few things out of the thought process on this.

#1 After splitting the wood, what was the "inside" and "outside" are no longer the same. You can have wood that was considered outside wood now being considered inside wood. You can also have wood that was considered inside wood now being considered outside wood.

#2 Because of the above statement, being able to really make a comparison between fall and spring cut wood, I think we would need to compare wood that is seasoned in the round (or at least seasoned in a similar shape etc). So lets just start off with comparing rounds. If you use fall cut wood, that has a higher MC inside, it is true that the gradiant is already started, however I think this actually would slow down the seasoning. The reason being is that that higher MC in the middle has to diffuse a further distance. Whereas with spring-cut wood, the higher MC on the outside would diffuse out more quickly, leaving the center with a lower MC. Because the center is what takes the longest to season you want the center MC to start off as low as possible to begin with.

It's hard to explain what I'm trying to say so I'll try an analogy.
When placing the stove in your house you always place as close as possible to the place you want the heat right? You want the heat source to be as close as possible to where you want the heat to go because you don't want to have to worry about it diffusing or being transported to where it needs to be. The same can be said for the moisture, because it leaves the wood on the outside (if it's left in the round), you want as much moisture towards the outside as possible because that is going to diffuse faster.


But my real opinion is that it doesn't matter. I burn free wood, and when you have free wood presented to you, you typically don't wait for it to be the proper season to go cut it. You take it when you can get it where you can get it and you let it season. The difference in MC and all that is negligible once the wood is split.

BTW, I'm not trying to be argumentative, just trying to present things from a different approach in case you hadn't considered them.

Backwoods has it right you just get far enough ahead so you cut anything anytime, for me it is interesting to talk about the drying times and what effects them.

CountryBoy19 said:

When placing the stove in your house you always place as close as possible to the place you want the heat right? You want the heat source to be as close as possible to where you want the heat to go because you don't want to have to worry about it diffusing or being transported to where it needs to be. The same can be said for the moisture, because it leaves the wood on the outside (if it's left in the round), you want as much moisture towards the outside as possible because that is going to diffuse faster.

BTW, I'm not trying to be argumentative, just trying to present things from a different approach in case you hadn't considered them.

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CB, I don't perceive you to be argumentative at all. Still, with no disrespect meant, I think you are comparing watermelons and cannonballs. The mechanisms behind heat transfer are entirely different from those behind water movement. For chemical reasons, water will diffuse from an area of high concentration to an area of low concentration. Yes, it will also dry on the outside for another chemical reason, so you will likely get water moving in two directions for quite some time. As far as splitting is concerned, having more water on the inside means that the wettest part of triangular shaped splits will have the shortest distance to travel through the wood since the apex of the triangle is the thinnest part. That should make them dry faster. Of course, I'm not claiming to be an expert on all this, just thinking out loud like the rest of you. Maybe one of our engineers or chemists will show me the error of my thinking. Certainly wouldn't be the first time, and I can deal with that.

Moisture content differences

The chemical potential is explained here since it is the true driving force for the transport of water in both liquid and vapour phases in wood (Siau, 1984). The Gibbs free energy per mole of substance is usually expressed as the chemical potential (Skaar, 1933). The chemical potential of unsaturated air or wood below the fibre saturation point influences the drying of wood. Equilibrium will occur at the equilibrium moisture content (as defined earlier) of wood when the chemical potential of the wood becomes equal to that of the surrounding air. The chemical potential of sorbed water is a function of wood moisture content. Therefore, a gradient of wood moisture content (between surface and centre), or more specifically of activity, is accompanied by a gradient of chemical potential under isothermal conditions. Moisture will redistribute itself throughout the wood until the chemical potential is uniform throughout, resulting in a zero potential gradient at equilibrium (Skaar, 1988). The flux of moisture attempting to achieve the equilibrium state is assumed to be proportional to the difference in chemical potential, and inversely proportional to the path length over which the potential difference acts (Keey et al., 2000).

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Taken from this excellent Wiki page on wood drying:

http://en.wikipedia.org/wiki/Wood_drying

And you thought this drying process was simple...

Backwoods Savage said:

And you thought this drying process was simple...

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:lol:

Ya, Dennis, better bone up on your calculus if you want to be a real burner. Or at least get a little experience under your belt. ;-P

Now I have to do math before I load the stove? :blank:

I was accustomed to only using the "if it's 18" or less it fits" math. :lol:

I killed one and left it standing. It was dry when I cut it down a year later- except for a few good rounds in the base which were completely saturated

Adios Pantalones said:

I killed one and left it standing. It was dry when I cut it down a year later- except for a few good rounds in the base which were completely saturated

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makes me wonder if the oak wouldnt dry/drain better if it was stacked VERTICALLY!

BLIMP said:

Adios Pantalones said:

I killed one and left it standing. It was dry when I cut it down a year later- except for a few good rounds in the base which were completely saturated

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makes me wonder if the oak wouldnt dry/drain better if it was stacked VERTICALLY!

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duh! ever heard of gravity?

BLIMP said:

Adios Pantalones said:

I killed one and left it standing. It was dry when I cut it down a year later- except for a few good rounds in the base which were completely saturated

Click to expand...

makes me wonder if the oak wouldnt dry/drain better if it was stacked VERTICALLY!

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I like that I am going to hang the splits like tobacco.

cptoneleg said:

BLIMP said:

Adios Pantalones said:

I killed one and left it standing. It was dry when I cut it down a year later- except for a few good rounds in the base which were completely saturated

Click to expand...

makes me wonder if the oak wouldnt dry/drain better if it was stacked VERTICALLY!

Click to expand...

I like that I am going to hang the splits like tobacco.

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been suggesting such for awhile, glad to hear ure trying it & ARENT WHISKEY BARRELS MADE OF SMOKED OAK?

Dune said:

BLIMP said:

Adios Pantalones said:

I killed one and left it standing. It was dry when I cut it down a year later- except for a few good rounds in the base which were completely saturated

Click to expand...

makes me wonder if the oak wouldnt dry/drain better if it was stacked VERTICALLY!

Click to expand...

duh! ever heard of gravity?

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You killed one, what did you use to kill one with?? :ahhh:

OK...so now it is January and I went to the same stand of trees. Cut an oak and squared a cubic foot of wood out. Then I loaded it and took the cube home and weighed it. Came out to 63lbs. Last one cut in the summer was 64lbs. Thats too close to call.