Wavy cuts in pine
Troubleshooting the cause of wavy cuts in pine. August 10, 2000
Q.
I am experiencing wavy cuts on 2 x 4s and some boards are coming out with a crook along the length of the board; could it have something to do with stress?
Are the waves present at the time you are cutting or after the wood has dried? If you are getting waves during cutting it could be caused by a disturbance in the set of the teeth in your blade in a selected area. Have you changed the blade to see if it solves the problem?
The waves are created during my cuts and I even slowed my feed rate down and changed blades. The cuts got a little better, but not much. There is no sap in this pine; it's pretty dry already. Might it be too hard?
If the lumber is crooked when it is green and just as you saw it, the problem is called growth stress. It is typically a result of the juvenile wood, the first 18 years, or rings, in the log.
Since you indicate that the wood has dried some, it could also be a result of compression wood shrinkage. Do you know what compression wood is? Waviness (short waves) in dried wood is not unusual, due to the higher density of the wood when dry and the difficulty in getting a saw to run straight in dry wood.
The saw wants to follow the grain rather than the direction you want; dry wood is so strong! Try sawing parallel to the bark (which will be along the grain) on all faces. Also, a wider blade will help. Make sure that the blade has as high a tension as possible so it cannot wander too much. Sharp, sharp, sharp (including the edge of the gullets).
Gene Wengert, forum moderator
If the waves are at the knots then your speed is too high; slow down for the harder wood in the knots. Check your blade guide rollers also, they must hold the blade parallel to the bed.
