Oak seasoned for one year is still wet!

[annette]

I got a lot of wood, some of it oak, last Jan-March, (I volunteered with a nature group to open up savanna, and they give the wood away) and it's been sitting stacked on concrete for a year. I covered it with plastic in December, some just on the top, some covering the sides too. Everything is 4-10" diameter, and it's 18-26 inches long.

Today I started working on that stuff, in part hoping it would be seasoned enough to burn now. I was cutting stuff to fit the stove, and/or splitting it. The wood looked wet, and my digital moisture meter had readings of 25-35%. ^*&%&^$!! Oak that's been sitting for one year, mostly cut to length, still has that much moisture??

There were some other hardwoods that were around 25% moisture too, so it wasn't just the oak. I think the wood was probably cut after the sap rose, I know at least some of it was cut as the trees were leafing out. Would January-cut wood have had the sap up, too? I didn't have a moisture meter back when I got it, so I don't know what the reading was when it was freshly-cut.

Is the darn stuff going to be ready to burn this year?? Do I need to build a wood kiln? (Wood that the meter says is 19-20% moisture doesn't do well in my stove, unless it's mixed with dry stuff)

 

[wendell]

Oak isn't going to dry until it is cut and split and then takes 2 years so it looks like you are working on 2011 wood.

Sorry to be the bearer of bad news.

 

[LLigetfa]

Why would you wait a year to buck and split it? It's not going to dry much in log form.

 

[Eric Johnson]

Wood needs to be cut and split and stacked for at least a year for it to dry out well--preferably two. You can speed the process, however, by moving it indoors so that it stays dry and preferably warm. Actually, 25-30% mc isn't all that bad. Most people would consider that pretty dry. But if you're waiting until you want to burn it to split it, then you're never going to have dry wood.

 

[annette]

Well, my stove takes 22" wood, so I didn't think that the extra 4 inches on some of the logs made that much difference in seasoning it. Are you seriously telling me it does? Likewise with splitting, since the biggest logs were 10", but most were 4-6" diameter. I did about 2 cords of this last spring, and then a lot of interesting stuff happened in my life, and here we are. I'd read a lot of posts on here about seasoning wood, and having stove-length pieces seemed to encourage water loss more than splitting (due to the cell structure of wood), but maybe this is my big lesson in the water-holding power of that bark.

Eric, you said that 25-30% isn't bad, but I guess my stove is picky. This wood is closer to the house than the woodpile, and I'm out of old oak, and I'm almost out of everything else, so yes, it would have been nice to burn it now. Do you think the MC will drop to 20% or below by next autumn/winter?

Thanks for your thoughts.

 

[johnsopi]

Splitting the wood give a huge increace in surface area, wish is need for drying.

 

[Backwoods Savage]

Annette, as long as you get the wood split now it should be ready next fall.

To be sure it seasons well, stack it so that the wind will hit the sides of the piles. Sunshine is also good but wind is even better.

This time when you stack the wood after splitting it, leave it uncovered all summer long. This will allow for maximum evaporation of the moisture. We don't cover our wood until late fall or early winter and then cover the top of the piles only. Do not cover the sides or ends. Yes, the rain will hit the sides and ends but the wood won't soak up that moisture and it will dry usually within 24 hours or sooner just from the wind after a rain.

If you want some of this to stay in rounds, the 4-6" should be okay if you leave them out again this summer but those larger logs do need to be split.

Good luck, and I hope you have a hydraulic splitter.

 

[WOODBUTCHER]

Annette,
A good way to tell if your split oak is ready ......is by just looking at the bark. Here are some pics of some red oak that was bucked/split/stacked in Jan 2008. (left overs from a green grapple load June 2007...so basically it sat in log form for about 8 months) When re-split 9 times out of 10 dry oak will not have a sent to it. The wood will have a uniform dull color on the inside also. I dont burn any of my oak unless there is some sort of bark seperation or falling right off.
And of course I know it's been split and stacked 13 months ago by me and I can hit 600 easy with my Oslo. Hope this helps....

WB

 

[Adios Pantalones]

Annette,
A good way to tell if your split oak is ready ......is by just looking at the bark. Here are some pics of some red oak that was bucked/split/stacked in Jan 2008.

WB

I disagree. I have a lot of oak that is very dry, and the bark is well affixed to the wood.

 

[myzamboni]

Well, my stove takes 22" wood, so I didn't think that the extra 4 inches on some of the logs made that much difference in seasoning it. Are you seriously telling me it does? Likewise with splitting, since the biggest logs were 10", but most were 4-6" diameter. I did about 2 cords of this last spring, and then a lot of interesting stuff happened in my life, and here we are. I'd read a lot of posts on here about seasoning wood, and having stove-length pieces seemed to encourage water loss more than splitting (due to the cell structure of wood), but maybe this is my big lesson in the water-holding power of that bark.

Eric, you said that 25-30% isn't bad, but I guess my stove is picky. This wood is closer to the house than the woodpile, and I'm out of old oak, and I'm almost out of everything else, so yes, it would have been nice to burn it now. Do you think the MC will drop to 20% or below by next autumn/winter?

Thanks for your thoughts.

Not scientifically accurate but consider this (in response to what I put in bold in your post above):

If a 16" long split takes 12 months to 'season' 12months/16inches= .75 ratio

22 inches X .75ratio= 16.5 months.

 

[CrappieKeith]

The dryer it is the more btu's that are available.

I talked to a gal last week that said we have good wood.....cut it down last Sunday.
Covering wood is a mistake.As mentioned the sun and wind are great drying factors.
Wood above 20% moisture will be too wet.20% moisture in wood will net out 8000 btu's per lb. available.
That does not mean your furnace is capable of making and then exchanging that heat. It just means that's what's available.
Kiln dried wood for example will make 12,000 btu's per lb.,but you do not want to burn wood that dry. It make toooooo
hot of a fire and will warp most steels in a firebox.

 

[Todd]

The dryer it is the more btu's that are available.

I talked to a gal last week that said we have good wood.....cut it down last Sunday.
Covering wood is a mistake.As mentioned the sun and wind are great drying factors.
Wood above 20% moisture will be too wet.20% moisture in wood will net out 8000 btu's per lb. available.
That does not mean your furnace is capable of making and then exchanging that heat. It just means that's what's available.
Kiln dried wood for example will make 12,000 btu's per lb.,but you do not want to burn wood that dry. It make toooooo
hot of a fire and will warp most steels in a firebox.

From what I've read there is only 8600 BTU's per pound of any type of wood at 0% moisture content.

 

[KarlP]

Splitting the wood give a huge increace in surface area, wish is need for drying.

However wood dries a LOT faster along the length of the grain than across the grain, so its not close to linear.

 

[Hogwildz]

The dryer it is the more btu's that are available.

I talked to a gal last week that said we have good wood.....cut it down last Sunday.
Covering wood is a mistake.As mentioned the sun and wind are great drying factors.
Wood above 20% moisture will be too wet.20% moisture in wood will net out 8000 btu's per lb. available.
That does not mean your furnace is capable of making and then exchanging that heat. It just means that's what's available.
Kiln dried wood for example will make 12,000 btu's per lb.,but you do not want to burn wood that dry. It make toooooo
hot of a fire and will warp most steels in a firebox.

From what I've read there is only 8600 BTU's per pound of any type of wood at 0% moisture content.

Agreed. And round here, no such thing as too dry. Bah
Always open offer here for someone that wants to trade " too dry" wood for some that is less dry.

 

[Adios Pantalones]

Splitting the wood give a huge increace in surface area, wish is need for drying.

However wood dries a LOT faster along the length of the grain than across the grain, so its not close to linear.

Splitting it in half (thickness wise) should speed drying by about a factor of the square of the difference.

An observation- in round form, wood dries very slowly. In split lengths (6' or more) it dries quickly. I dealt with a lot of split stave lengths for bow making.

 

[fossil]

The area of the freshly exposed surface of the interior of the split wood that's not covered by bark makes all the difference, regardless of the length. Wood in the round with the bark on will take the very longest to season, unless you buck it into pucks. Rounds bucked to a length and then split into however many sections it takes to make wood you're comfortable handling and that fill your stove nicely is ideal. Typically, the wood is bucked to length first, and then split...just because it makes the most sense to do it that way with the tools we normally use. After it's split, it's stacked someplace where it can season for whatever time is required for the species of wood and the conditions prevailing where it's stacked. It takes time. Rick

 

[Eric Johnson]

I pretty much agree with Rick. The more you split it the faster it's going to dry. Loose bark is one of my measures for how dry wood is, but weight is probably the best indicator. Not all species or individuals within a species will shed their bark after drying (I guess because the wood shrinks more than the bark), but most do.

The thing about stacking indoors in the winter is that the heat and much drier air will both make it dry a lot more quickly, especially if it already has a good start, or the bound water is already gone and all you need to do is dry out the moisture between the cells. People hesitate to bring any significant amount of firewood into their homes, which I understand. That said, I routinely stacked 8 full cords in my basement in my previous house for 9 years, and never had a problem. Just don't do it in the summer, or you'll wind up with a big science project.

 

[jebatty]

Almost all of my dry fire wood has the bark tight to the wood, regardless of species (oak, aspen, birch, ash, pine), the exception being wood that is partially decomposed prior to bucking and splitting. Live wood bucked and split means tight bark for my wood.

I know others have different experience, but I think it is important to get air circulation under the wood stack, and therefore I stack my wood on 6" +/- logs or 4x4's to get that air circulation. Also, except for wood in the woodshed which is covered by a roof, cover only on top, not the sides, to allow air circulation through the stacks. Top cover best is corrugated steel or other covering that allows air to circulate across the top and not allow moisture to condense on the cover, like a tarp, and drip back into the stack, or simply allow the top wood to remain wet.

Many woods, if properly split and stacked, can dry in one summer, but this can be iffy. If you have space, plan for at least two years wood supply on hand, so each years wood supply has dried 2 summers; 3 is even better. That way you always will have good, dry firewood, no to minimal creosote, and a warm heart and hotter significant other.

Nature took millions of years to produce gas and oil; 2-3 years for good wood is a natural bargain.

 

[Dune]

Two points, 1. A solar firewood kiln can be as simple as a clear plastic tarp tented over the wood pile in such a way as to not touch either the wood or the ground, and can reduce drying time by more than half. 2. I routinely bring a week or so worth of wood into the room where my stove sits, where it becomes much dryer before I burn it, regardless of it's initial moisture content.

 

[Adios Pantalones]

Two points, 1. A solar firewood kiln can be as simple as a clear plastic tarp tented over the wood pile in such a way as to not touch either the wood or the ground, and can reduce drying time by more than half. 2. I routinely bring a week or so worth of wood into the room where my stove sits, where it becomes much dryer before I burn it, regardless of it's initial moisture content.

I saw a study on tarp based wood dryers that showed they slowed wood drying. More air flow is generated by wind than the convective chimney, and the tarp chanels moist air around the stack as it rises from splits.

I had a plan for a solar pre-heater- a black metal box to preheat the air a great deal and increase the chimney effect enough to make it dry quicker. Not sure it would work, but I did look into passive simple methods.

 

[chad3]

I've got 3" oak that is in round form (would it be any different?) and it is still soaked. This stuff needs to be split or seasoned.

 

[Adios Pantalones]

Chad- I hear ya- splitting improves drying even for relatively small pieces because of the continuous rings and the bark, from what I've observed.

 

[Apprentice_GM]

1. A solar firewood kiln can be as simple as a clear plastic tarp tented over the wood pile in such a way as to not touch either the wood or the ground, and can reduce drying time by more than half.

I saw a study on tarp based wood dryers that showed they slowed wood drying. More air flow is generated by wind than the convective chimney, and the tarp chanels moist air around the stack as it rises from splits.

Dunebilly, I concur with AP - I disagree solar kilns dry wood faster from personal experience and only know of scientific studies dismissing solar kilns (solar kilns not worth the effort). There is a paper I found and read years ago, and have referenced previously on these forums, which you may find worth reading - US Department of Agriculture (Pacific Northwest Research Station) - Research Note PNW-RN-450 August 1986 titled “Drying Firewood in a Temporary Solar Kiln: A Case Study”

 

[Apprentice_GM]

Splitting the wood give a huge increace in surface area, wish is need for drying.

However wood dries a LOT faster along the length of the grain than across the grain, so its not close to linear.

Splitting it in half (thickness wise) should speed drying by about a factor of the square of the difference.

An observation- in round form, wood dries very slowly. In split lengths (6' or more) it dries quickly. I dealt with a lot of split stave lengths for bow making.

1) "However wood dries a LOT faster along the length of the grain than across the grain, so its not close to linear."
Do you have a ratio for this? Any study? I am curious to know so as to work out optimum lengths and splits for various rounds. In other words, say you have a 24" long round @ 8" diameter and split it once into 2 x 24"" half-rounds. I would have thought that splitting a half-round into 2 x 24" quarter-rounds, and exposing much more surface area of much less interior wood (so a much better surface area to mass ratio), plus giving trapped moisture <2" to escape across the grain but 12" along the grain, was much better than cutting the half-round into 2 x 12" half-rounds (with 6" escape along the grain but 2" escape across the grain). So far I have worked on splitting more, maybe I should buck shorter.

2) "Splitting it in half (thickness wise) should speed drying by about a factor of the square of the difference."
Versus cutting in half? Any ideas?

3) AP, a potter AND a bow-maker? Are you sure you have the right millenium? I have a small obsession with the traditional process of making katana's (japanese swords) myself, although I've not made my own (yet). You amaze me.

 

[rphurley]

Today I resorted to burning some oak that I cut about a year ago. It has been stacked in the sun and wind since June. The stuff burns like junk. The wood I had been burning had been seasoned for several years and burned clean and hot. My recommendation to anyone who doesn't season their oak for two years is to give it the extra time and you'll be pleasantly surprised.