What might cause severe checking?

[Mike Stelts]

A neighbor brought me a board to plane for him. He cut it with a chainsaw jig. Moisture was 22%. What could cause such checking? I've never seen anything this severe, so I had no idea what to tell him. It runs the entire length, not just in from the ends.
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[Edward Weber]

Short answer, many things.
Rapid drying, internal stresses, wood species.

wood is a natural product and while we can "predict" what it will do, it will do what it wants to.

[Brian Tymchak]

IMHO, that's not checking but wind shake. Wind shake is when a tree is subject to severe winds, that bend and twist the tree violently. I think the early wood in the rings is weak and will separate. The width of those rings also look huge meaning the tree grew rapidly with lots of water. That would also weaken the tree and be more easily damaged in a wind storm.

[John Lanciani]

To add to Brian's answer, ring shake can also be caused by felling a tree onto a hard surface or across another tree trunk. The stress from the impact can separate the growth rings as shown in your pic.

[Zachary Hoyt]

I have also read about shake being caused by some sort of bacterial infection in some hemlock logs, though as I understand it (and in my experience) it is usually confined to the butt log. I don't know if this kind of thing also happens in other species.

[William Hodge]

Lightning will do it.

I had a 24" Red Oak beside a field that got struck by lightning. I dropped it before it died, because dead trees are hard to drop. The lightning had separated the rings like that, right around the tree, quite a few rings in. It was a minor strike.

Another 21" Red Oak that was struck by lightning a few years earlier had one side of the trunk turned to splinters.

[Bradley Gray]

i had a lightning strike on a ridge top cherry once that split about 30' of trunk into 3 pieces and scattered shards over a 200 yard radius. The power of nature!

[Mike Stelts]

Thanks guys. Your 3 answers make sense, wind shake, hard fall, or lightning. I never experienced those, so I was thinking down the wrong path of severe checking.

[Jim Becker]

No matter what the real name for it might be or the cause, that's clearly "firewood shake" from the photo. Sadly. You might be able to rip off some rift sticks from the edges for your friend, but the center of that board is, IMHO, a lost cause.

[Mike Stelts]

Fortunately, he wasn't too disappointed when I told him that he spent his time cutting thin firewood.

[John TenEyck]

You are all wrong. Slather it with gloss epoxy, mount it on some hairpin metal legs, and advertise it on Etsy for a couple thousand dollars as a unique and special, one of a kind, hand crafted heirloom.

John

[Brian Runau]

You are all wrong. Slather it with gloss epoxy, mount it on some hairpin metal legs, and advertise it on Etsy for a couple thousand dollars as a unique and special, one of a kind, hand crafted heirloom.

John

Now that's funny and would probably work. Brian

[John Lanciani]

You are all wrong. Slather it with gloss epoxy, mount it on some hairpin metal legs, and advertise it on Etsy for a couple thousand dollars as a unique and special, one of a kind, hand crafted heirloom.

John

Always making lemonade, you continually inspire me John.

[Edward Weber]

You are all wrong. Slather it with gloss epoxy, mount it on some hairpin metal legs, and advertise it on Etsy for a couple thousand dollars as a unique and special, one of a kind, hand crafted heirloom.

John
Don't forget to put LED's into the crack for that visual, POP

[Jim Becker]

Don't forget to put LED's into the crack for that visual, POP
They have to be multi-color, too, that changes colors constantly... :D

[John K Jordan]

Thanks guys. Your 3 answers make sense, wind shake, hard fall, or lightning. I never experienced those, so I was thinking down the wrong path of severe checking.

From what I've read the jury is still out on the cause of common ring shake. It well may have more than one cause.

Some shake variations: https://en.wikipedia.org/wiki/Shakes_(timber)

In my experience a log with ring shake is best used as firewood. I've seen it several times when processing wood for turning blanks, most dramatically in walnut and chinese chestnut, once in cherry. Can be dangerous on the lathe if undetected!

Compression failures (including felling shakes, thunder, rupture, transverse shakes, cross breaks, cross fractures, and lightning) are often cross-grain fractures. Lightning can do unpredictable things! I've had trees blown apart halfway up the trunk and split all the way to the ground, compromising nearly the entire tree. One 24" poplar now has an exposed rotting interior but since the strike the tree has added 6" of healthy growth 3/4ths of the way around the circumference and has healthy upper growth! Maybe it will survive.

In one case, however, lighting hit a large yellow poplar tree and made a clean groove down one side of the log, maybe 3" deep. The surrounding wood came off the mill with unusual color. You can see a little bit in the 10/4 planks in this picture:

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JKJ

[Alan Schwabacher]

Maybe hedge your bets and embed both LEDs and firecrackers into the epoxy. That way any time you tire of the flashing lights you can turn it into kindling.