Was it me, or the tree? Boards splitting into Y-shape

[NotEnoughTime]

Looking for advice from the wise old men here...

I have a stack of white oak 16' long slabs that I cut 1" thick, most of which have turned Y-shaped while air drying this summer (in a shady spot).  Similarly about 1/2 my stack of black walnut is widening at one end, with a widening air gap in the middle.

My question - did I do something wrong?   I might expect this for the center board if I kept the pith in, but most of the boards have split ,not just one.  These were both from straight upright trees, not leaners, but apparently there was stress in the wood?  One of the black walnut boards cracked and split before I took it off the mill, so those were less of a surprise.

So... was it me, or the tree?  Could I have predicted this and cut these differently?  Was there something I could have changed in the way I sawed or dried the wood to prevent the splitting?



 

 

[Southside]

From the looks of the stack, presuming you stickered as they came off the saw, the log had some stress in it and end checked, then followed the split until the grain held it together.  You didn't do anything wrong.  

Folks like to split white oak because it spilts easily, well, this one did too.  Maybe you could have sawn the log 90° to the way you did, but then you probably would have had bow in your boards.  At least the way they are you can edge them down to a narrower, but square piece of lumber.  

I had some pine 1x6 we tossed into the edger a couple of weeks back.  They were dead straight and I needed 1x3's so we decided to split them.  One batch didn't work out so well, as they came out of the edger they were blowing apart and not a single one was straight any longer.  Some blew into two pieces before the saw even cut them.  Stress in lumber can have an odd way of disguising then showing itself.  

[Ljohnsaw]

Have you cut a lot that did not do this?  Related to the time of year the trees were cut?  Not an expert on hardwoods by any means - I only have softwoods available to me.  But, I noticed you cut it all live-edge.  Did you need live edge?  It would seem to me that leaving the sapwood on with the bark would add stress to the wood.  If you don't need the live edge, you should make a cant and then saw through and maybe have better luck.

[NotEnoughTime]

Have you cut a lot that did not do this?  Related to the time of year the trees were cut?  Not an expert on hardwoods by any means - I only have softwoods available to me.  But, I noticed you cut it all live-edge.  Did you need live edge?  It would seem to me that leaving the sapwood on with the bark would add stress to the wood.  If you don't need the live edge, you should make a cant and then saw through and maybe have better luck.

I've milled a bit over 12,000 bf in the past two years since I bought a mill. These are the only logs that have split into a Y-shape, but they are also the only white oak and black walnut trees that I have milled. The white oak was cut in June, the black walnut was an October urban removal. The other black walnut log from the same tree checked but didn't split, but it had knots and gnarls. 

I've milled red oak, white pine, ERC, and several types of maple which haven't split.  Some of the maple twisted like a corkscrew, but I could see why that happened from looking at the grain pattern below the bark.  Maple is my favorite wood so I was hoping I could still use that tree.... the boards looked straight coming off the mill... so I was hopeful.  Nope.  Learning one log at a time what's worth doing and what isn't.
When I started milling I just cut slabs with live edge on both sides.  I thought it would give flexibility later when I decided what to use if for.  I now leave only one side live edge, as I've learned it's much easier to use when you have a straight side to run through the jointer.  I also remove the pith, or box it.  It gives too much 'character' to the slab when you slice through it.  (Friends who ask me for wood often pick the slabs that have visible saw marks, knots, splits in the pith, checks, bark inclusions, worm holes, etc.  I see bad saw-milling and low quality logs.  They see 'character'.  The better I get at this the more I think I'm going to disappoint them.)

[Don P]

Give this a read for more on growth stress;
Growth stress

[doc henderson]

maybe wind stress/shake.  it does not follow the growth rings so maybe more of a one time lateral stress, maybe in falling.  had it dried a while?  many unseen defects present before sawing, show up after sawing and drying.  have you watched the seminars on the national hardwood lumber association website, by @GeneWengert-WoodDoc .  lots of good info.  it appears to have been that log.  sounds like most of what you do turns out well if these are the only two.

[doc henderson]

I doubt you have a before pic of the end of the log, but would be interesting to see.  for about a thousand dollars you can just fill it with epoxy.   :D :D :D

[Magicman]

That is a classic example of what can happen if the pith check is not oriented horizontally before sawing through.

[NotEnoughTime]

That is a classic example of what can happen if the pith check is not oriented horizontally before sawing through.

Thanks, Magicman.  This explains the black walnut log.  I wasn't using end-sealer yet when I sawed that, and I recall deciding to cut with the pith crack vertical, figuring I would cut down the middle later.  Nature split it for me.

[Southside]

End sealer will help with checking caused by rapid drying, but it won't help with stress / pith cracks. 

[YellowHammer]

Yes,

That is a classic example of what can happen if the pith check is not oriented horizontally before sawing through.

I agree, and typically the log will give clues that this will happen, even if the end check isn't oriented correctly relative to the stress in the log.

Walnut, especially with such a wide sap ring as this log has, would be very prone to making McDonald's arches if cut perpendicular to the pith crack.  

End sealer would not do anything to help these.

Leaving the sapwood on the board will amplify the stress when drying.

Normally, when doing a routine sawing pattern instead of live edge, on logs such as these, the initial flitches would have been peeling up like a carrot peel, so would have give a clear indication of the level of internal stress, and indicated the log should have been rotated 90°.  You won't see that when live edge sawing.

[Ianab]

On a brighter note, rip the boards down to smaller sizes and recover what you can. Be some decent quarter-sawn boards there once you trim them up. 

[YellowHammer]

I've made some McDonalds arches that pretty much curled around and touched each other. :D :D  I always tell people it takes years and years of experience to do that, and it's a company secret :D :D.

[Al_Smith]

I don't claim to be a lumber man but this is how I do it .When it's cut I seal the ends of the logs with roofing tar .Before it's milled I cut a cookie off each end .After it's milled I use anchor seal on the lumber .Roofing tar will take weather, anchor seal not so well  .I do of course get a few splits but not many .

[GeneWengert-WoodDoc]

Although unusual for North American species, it is growth stress in the tree.  No solution.