Hemlock milling

[MrMoo]

Hi Folks,
Over the last couple of weekends I have been milling hemlock logs that were cut down in early November. They are good solid logs with no rot or anything like that. Like much hemlock some have a sweep of 1-3" in them. The length on them is 14-16' The problem I am having is that when milling dimension stock like 2x8s or 2x10s the boards split along the grain lines giving me useless lumber. I only seem to get good lumber if it only comes out of the heart wood but that limits me to 2x4s or 2x6s.
I have been careful to try & not have the grain run out the side of the boards but with hemlock that seems almost impossible on some cuts.
I have wondered if the logs are too green. The hemlock I have milled in the past did not have this problem but it was down for 4-5 months.
I have also wondered if the temperature has been an issue since its been mostly in 30s during the day since they were cut.
Does anyone out there have any experience with this? Any ideas or suggestions would be welcome.

[Tom]

Well Mr. Moo, (that's funny)  I don't cut hemlock but have experienced the symptoms you describe when cutting pond pine or sometimes cypress.  When I cut a log with a sweep and am cutting boards from the side of the sweep they may split. The board crawls to the side until I approach the end of the cut and then it splits. If I cut the board from the top or bottom of the sweep the the tendency to split is less.  I also notice that I can minimize splitting if I creep throught the last foot of the cut.  It doesn't always work but it helps.  

There is a note in the Knowledge Base that talks about cutting sweeps. You might like to read that.  Perhaps someone with Hemlock experience will post now

[Ron Wenrich]

It almost sounds like you have shake in the logs.  I've sawn hemlock that would have a shake line in it, but usually I've been able to saw around it.

1 to 3" of sweep isn't a lot on a big log.  On a small log, that can mean a lot.  I can't remember having that problem with hemlock.  But, I don't saw a great deal of it.

[MrMoo]

Ron,
I have not heard of the term shake line before. Can you explain it?

The logs I am talking about run anywhere from 11-14" diameter at the small end with 14' length.

[Ron Wenrich]

This is a picture of a sycamore log that is in another thread.



It shows a shake line.  Hemlock is also prone to shake.  Sometimes it isn't as visible.  Shake is where there is a seperation in the growth ring.  Sometimes it can be all the way around the growth ring.

[wiam]

Sounds like shake to me, usually  gets less shake farther up the tree.  Some butt logs almost fall apart before they hit the mill.

Will

[Brian_Bailey]

I've sawn E. Hemlock 1x12" for siding, pull the board off the mill and a big chuck will fall right out of the center making the board useless unless you can get some battens out of it. When I was sawing hemlock, I kinda figured on throwing a good third of the stuff on the scrap pile. Not much profit, thats why I don't deal in it any more.

[MrMoo]

First I wanted to say thanks to everyone who responded.

After seeing the picture that was posted my logs have the shake problem.
I can still get lumber from them since it seems like the heartwood is not so severely affected. There will just be more waste than I would have liked.

[Don P]

I've heard that hemlock gets a soil born bacterial infection that often causes shake. It slowly moves up the tree from the roots, travelling at inches per year. Livestock root damage is supposed to help cause the infection.

[Brian_Bailey]

The logger I deal with told me that when they cut hemlock from low wet ground it is almost always shaky. I donT know if bacteria has anything to do with it but it seemed that some logs that had shake were pretty smelly. If you can call smelly pretty? :