sawing up a curved log

[Tom]

Limbs aren't more prone to shake than trunks.  Matter of fact, the bottom of the trunk is where I see most shake.  Shake is ring separation.  I'm not a bio chemist but have been told that a bacterial infection in the tree is responsible for the weakness between rings and movement causes them to separate.

What you will see in limbs is a lot of compression/tension (reaction)wood. you can identify it by off-center pith.  This phenomena is caused by the tree trying to "right" the member by putting on larger cells on the bottom than on the top.  This wood is generally more brittle than regular wood and may have an orange color in southern yellow pine.


You can saw decent boards from wood like this, sometimes, but don't mix the two types of wood. (tension and compression)

[ronwood]

Tom.

Could you clarify your following quote?

You can saw decent boards from wood like this, sometimes, but don't mix the two types of wood. (tension and compression)

Thanks
Ron

[Paul_H]

Here is a good link.

Tension&Compression

[Tom]

Thanks Paul,
I was away looking for that picture too.

I have misled in the above statement to indicate that the two designations of Reaction wood are found in the same stick.  As this old post states, they are two terms to define reaction wood in hardwood and softwood.

To clarify what I was trying to say, don't combine the wide grain of the bottom of the limb and the narrower grain of the top of the limb in the same board. Keep these two configurations in their own board and you will end up with a more controllable  movement in the board.
                               

[ellmoe]

[  Matter of fact, the bottom of the trunk is where I see most shake.  Shake is ring separation. 

Several years ago we had a large order of 1x12x8 cypress. We had just brought in some wood from Waldo (where's Waldo? ) , Florida. The bottom cut of each log was just big enough for this order. I had to leave the mill, and left instructions to cut eight feet offthe butt off of each log and to saw this order. When I returned I had 8000bf of 1x12x6! Almost every log of this size in that swamp  had ring shake in the bottom two feet.  Guessing at the age of the trees and looking at a pattern of broken tops, I figured that a major wind had hit the swamp, stressing all of these trees. After taking this hit ,we allowed two additional feet of "trim" and successfully cut the eight foot order.
Mark

[Fla._Deadheader]

  We find quite a bit of shake in the old Cypress logs. Doesn't bother us too much. With the size of the logs, I can usually saw around the shake and get good boards. Actually, it's the same as "Boxing the heart", only, substitute the shake for the heart.

  Old logs don't have the reaction type characteristics of young logs. I have heard that the water releases the tension in the logs. Don't know for sure. Even those with a VERY offset heart, just lay flat when we saw them.

[ronwood]

Paul_H & Tom

Thanks for the clarification.

Ron

[Dana]

Tom, Thanks for the info I was sawing up a large white ash over the weekend that had been leaning and had the growth rings off center. As soon as I cut into it it started to curl up. When cut another side there was only a minimum of lift. Didn't put two and two togather! Will use the tip in the future though.

[Ironwood]

I have had sucess with a chalk line and a ripping chain free handing it and slowly cutting. If you are careful you can get a good cut. Reid