Drying

[onetracker]

"For multiple rows it may be preferable to have the rows parallel to the prevailing wind." (common sense)

"Ideally stack should be elevated a foot or a foot and a half. (Again, Common sense)

"drainage can be important." (duh)

Good basic stuff there.

-Soupy1957

Common Sense - something rarely found in a government document!

..or a corporate one

 

[Battenkiller]

So does this mean that when wood begins to crack on the ends and throughout that it is fire ready? I knew this meant it was seasoning but I didn't know it meant that it was definitely ready to go in the fire. Am I reading this correctly?

No. :lol:

Seriously, cracking is only a sign that the very ends of the wood have reached a point below 28% MC or so. The ends dry 10-15 times faster than the sides in most species, so natural they will begin to crack way before the wood is dry through and through. I was only bringing up those photos as proof that green wood will dry to the point of end-cracking, even outside during the coldest part of the winter.

Here's a photo of that same batch of wood after it sat in the basement where the stove is for a week or so. Notice how much more severely checked the ends are? Well, I split some of that wood a few days later and measured it with a meter and it was still up over 30% MC. The outside surfaces didn't even register on the meter (below 6% MC). It takes a real long time for big splits of hickory and oak like that to dry all the way through to the very inside.

 

[Battenkiller]

BK, you should be promoted to wood scientologist, they should creat a position here for you.

I have 2 yr old red oak that has been on the racks drying. The 1.5 cords should be ready but after reading you material on free water I'm not so sure. After removing some of the splits from various places in the rack I went to re-split and check the MC with the meter. It was reading 20% or less (but nothing less than 17%) The weight felt right, the sound was there and the numbers seemed good from the meter. The only part missing was the checking on the end grain, the entire 1.5 cord had hardly and checks. I ran this by in another thread and I got thumbs up just based on the MC numbers. Your information now has me concerned whether or not this wood is ready. Tell me what you think plz.

Thanks for the promotion, what is my new pay scale?

Wood doesn't have to check in the ends, it just usually does. It happens when the ends get significantly drier than the middle and start to shrink at a different rate. When the middle hasn't reached the same MC, the drying ends will be under stress because they will not be allowed to shrink. When the stress gets great enough, the piece will relieve the stress in the form of cracks. However, if the wood dries slowly enough (at a high enough relative humidity, for example) the ends might not check at all because the entire piece shrinks at the same rate and no stress if created.

I'd be willing to bet that lots of folks near the East coast are seeing less end checking with wood they put up in June and July due to all the freakin' rain we've had this season. I know my wood is less checked than it usually is, and the stuff under cover is only at 17% MC (usually it will be around 14% by this time of year). The stuff that's been getting direct rain is even higher, up around 22% on the inside... but 17% on the outside, go figure, huh? It's been a real weird drying season.

 

[ewdudley]

I have 2 yr old red oak that has been on the racks drying. The 1.5 cords should be ready but after reading you material on free water I'm not so sure. After removing some of the splits from various places in the rack I went to re-split and check the MC with the meter. It was reading 20% or less (but nothing less than 17%) The weight felt right, the sound was there and the numbers seemed good from the meter. The only part missing was the checking on the end grain, the entire 1.5 cord had hardly and checks. I ran this by in another thread and I got thumbs up just based on the MC numbers.

My dry oak dining room table has no cracks at all, so there must be such a thing as dry oak with no cracks.

In the paper they have a lot of information about how to dry without cracking; slow drying, sealants on the ends of the pieces, out of the sun, out of the wind, and so forth. My guess would be you got lucky and the wood dried slowly and evenly without so much cracking.

 

[Battenkiller]

I didn't say this before, but I think this publication is a lot more than just "common sense". I've been a student of wood technology for over 35 years and it contains a lot of info I didn't know.

The Forestry Dept. has historically produced a lot of first-rate research. This is about as in depth as you are ever going to see outside a professional journal. I think this publication should be attached to some sort of sticky (along with a few other wood science links I know of). It addresses a lot of the variability found in wood drying, and would be an invaluable resource to new burners, even if the focus appears to be mostly on lumber at first glance.

 

[Jags]

I think this publication should be attached to some sort of sticky (along with a few other wood science links I know of).

Bk - get with BGreen or Craig (or any of the mods) and they can get you fixed up with a sticky. I think the info that was in the article and the others that you speak of would be a good addition for those that thirst for the knowledge.

 

[gpcollen1]

"For multiple rows it may be preferable to have the rows parallel to the prevailing wind." (common sense)

"Ideally stack should be elevated a foot or a foot and a half. (Again, Common sense)

"drainage can be important." (duh)

Good basic stuff there.

-Soupy1957

Nope - most mention perpendicular to the wind not parallel..

For multiple rows I thought you were supposed to stack so the wind would flow over the wood the best way possible, parallel would be the best choice would it not?

Sure that would be best. I just have heard many stacking perpendicular to the prevailing wind, which is good for the first row of course. Soupy said it was common sense but I don't think many people really think about it or have it correct...or even know which way the prevailing winds are coming from.

 

[Battenkiller]

The area you are in matters allot too. In the PNW, it's hard for me to believe wood dries much at
all in the Seattle winter, rainy, misty moist conditions but in Alaska at -10°f & low humidity it will dry better here.

Let's compare the two areas with tables taken from this publication:

http://www.fpl.fs.fed.us/documnts/fplrn/fplrn268.pdf

You can see by the EMC of the three cities throughout the year, there's not all that much difference between the three. It has to do with the average seasonal relative humidity in the area, not how much actual water (absolute humidity) is in the air at the time.

 

[Danno77]

I don't want to disrupt the stream of knowledge and learning going on here with what BK is saying (seems like for the 100th time, 'cause I actually listened before when he said most of it!), but someone was asking about wood being stacked perpendicular or parallel to the prevailing wind direction, so I wanted to comment on that really quickly:

If you have one stack, I imagine it could be best to stack perpendicular to the wind, especially if the wind could blow through it to some degree. What the article states is that multiple stacks are best stacked parallel with the wind direction. This would be because your foremost stack would block the wind to the other stacks if they were all perpendicular. If they are all parallel then the wind will blow right by the ends of your splits on every single row.

 

[bogydave]

Thanks BK,
Nice chart.
I'm a little more inland than Anchorage, but not as far as Fiarbanks, I'll interpolate a 1% less than Anchorage & be pretty close.
Started burning yesterday, the wood is burning great (burning mostly spruce with some birch mixed in, 2 yrs seasoned)
Can't even tell I'm burning when the cat kicks in, no visible vapors out of the chimney.
But it only getting 30 at night & high 40s daytime, burning 1/2 loads.

 

[Woody Stover]

(along with a few other wood science links I know of)

Someone posted a link in the course of a thread, end of last year or early this year, that discussed ring- and diffuse-porous woods and the microscopic structure of various species...excellent pics, too. I think it was a pdf. I haven't been able to locate the thread or the link. I was hoping that maybe you saved that link or had it previously, BK...