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I have 8/4 black walnut air dried for three years (northern Illinois). Huge clear boards: 20 inches X 12 feet. What a disappointment to pull some out today while looking for a special grain pattern. Many of the boards have long splits running three and four feet in from the end. Not normal is that? The ends of the boles were painted as soon as the tree was felled, it was sawn within two weeks, and has been stickered in the open shed since. What went wrong?
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I see that you are in Illinois and having lived there I know it can get really hot really fast. Seeing that you have thick slabs my bet is that they simply got too warm and too much air at once so they dried too fast. Because they are cracked that means drying too fast.
Horizon Lumber is one of those mills that specializes on large slabs and they dry them all the time. They take the moisture up to a high level and then pull it down slowly over the course of several months. I believe their kiln cycles for 2" thick wide slabs is about 6-8 months. My friend got 1000 bd ft of QSWO for them and he had to wait over a year for it.
Without paying a small fortune for a long kiln cycle you are left with the luck of Mother Nature for how fast she pulls the moisture out of the wood. In your case she got impatient. I have some 2-3" thick walnut that has been drying in upstate NY for ~5 years. There were trees that I planted when I was a kid. I had my brother cut them in early September and then them were milled in late November when it was cold. They slabs were placed on stickers and put inside the middle of a barn so not much air got to them. They dried perfectly with no cracks so I got darn lucky.
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from the dimensions of those boards sounds like a slice right through a log or a very big log
wide boards some times include the pith is that possible ?
stopping cracking on boards with the pith is very difficult
usually air drying walnut is a easy as it gets wide boards more difficult but doable but the center or pith very hard to get them dry without problems no mater what species your trying to dry
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Curlycherry said:
I have some 2-3" thick walnut that has been drying in upstate NY for ~5 years. There were trees that I planted when I was a kid.
I have not heard of this before, that must be a one of a kind feeling.....it is the perfect order of things to cut lumber you grew.....
Andrew
"That's like getting a running start and diving headfirst into the vortex."
Steve Freidman 4/21/2013
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Humanbackhoe said:
[blockquote]Curlycherry said:
I have some 2-3" thick walnut that has been drying in upstate NY for ~5 years. There were trees that I planted when I was a kid.
I have not heard of this before, that must be a one of a kind feeling.....it is the perfect order of things to cut lumber you grew.....
Andrew
[/blockquote]
It makes one feel VERY old. They got ideal conditions and grew pretty fast. Most of the growth rings were upwards of 1/4" thick. They were 42 years old when they were cut.
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oakey said:
from the dimensions of those boards sounds like a slice right through a log or a very big log
wide boards some times include the pith is that possible ?
stopping cracking on boards with the pith is very difficult
usually air drying walnut is a easy as it gets wide boards more difficult but doable but the center or pith very hard to get them dry without problems no mater what species your trying to dry
While juvenile wood is much weaker than the heartwood surrounding, it sounds to me like a growth stress that was released by end checks. They are normally self-limiting, because the dryer wood contracts and pulls apart only as far as it takes to get to expanded wet wood. Couple inches max, unless it encounters other weakness. Why they cut at 100/102" inches here. Trims to a clean 96.
Better to follow the leader than the pack. Less to step in.
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I agree that it doesn't sound like end checks from drying. Those should only travel a small way into the board as the faster drying on the end grain only extends about 6" max into the wood. After that, the wood is drying at the same (slower rate) as the rest of the board. Plus if an end coating was used it should have reduced the chances of that happening.
Possibly a heart check, which is internal growth and drying stresses cracking the wood from the centre, like a star check in an embedded knot.
Or, I wonder if the the log was actually damaged as it was felled? Incorrect technique can result in the felling notch closing up as the tree is 1/2 way down. This tries to "stall" the trees fall, and put tremendous force on the end of the log, enough to split the tree in 1/2 occasionally. Or it three impacted on a heavy branch first, rather than hitting the ground flat. Again stress on the log, from the top end this time created the cracks.
I don't think it's drying problem. The issue was probably present in the log before it was even milled.
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Considering your location, was this lumber salvaged from wind / tornado damaged trees? If so, google "shake" with respect to lumber milling.
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I had a similar experience last year with some 8/4 and thicker basswood. Anchor sealed on ends air dried under cover. I talked to a friend who has dealt in thicker stock for many years and he said it was due to freezing and thawing of the moisture in the thicker pieces. I had about 3500 bdft stacked and it only effected a few pieces, but it was not ring shake or drying checks but that was my situation your issue may or may not be the same. It is kind of a bummer when you notice it.
