Wednesday, March 26, 2008

Splitting Maple

Looks like winter is having its last gasp around here! One or two quick blasts and it should be over.



I recently purchased a beautiful hard maple from my sawyer. It looks like a cartoon drawing of a perfect tree. The heart is about the size of a quarter and the rest is clear straight wood.
I have resorted to sawing maple on my previous log which did not like to split, which taught me a few things. There seemed to be a higher yield by sawing and the blanks were easier to handle and chuck up than splits. This may be true, but my instinct is still to reach for the sledge and wedges rather than the chainsaw mill.




Above is a photo of the layout that I have commonly used to split maple. Really, it is the layout that works best with ring porous hardwoods, and I've used it out of habit. There are some problems with the layout such as the circular lines, the odd shaped trapezoid pieces and the fact that no line runs all the way from the bark to the heart.

Below is the layout that I now try to use with my maple. It more closely mimics sawing the wood, which gives square blanks and a clean grid that always goes straight from one side to the other.



There are only a couple of difficulties with this layout. To start the split, I score a line 1/4 inch deep along the entire length by striking a wedge or hatchet. This helps to direct the fracture. It is usually necessary on large pieces to simultaneously drive wedges along the length of the line to prevent weak areas from cracking. The other difficulty is the patience required. Oak and hickory etc... have weak layers between strong fibers, and the splits love to stay on the fiber line. With maple and other more homogenous woods, the splits tend to be more influenced by the mass of the splits. When the mass of the two parts being split is uneven, the line will run out toward the weaker side. By tapping the wedges gently, the fibers have more of a chance to separate, rather than shear under the uneven influence. I know that the impulse to swing a sledge hammer like you're driving railroad spikes is tempting, but in this case, it's all about finesse. It takes some practice, but I have found the higher yields and simpler approach worth it.
Good luck.

2 comments:

greg said...

A nice straight, uniform and compliant log is a thing of joy.

If you were using a froe to make these splits you wouldn't be needing to score across the log. Generally the logs are small enough (once they are quartered) to allow the froe to make one straight split right across, negating the need for you to 'score' across & thereby enabling you to be less patient.

When I saw your first picture with the round split lines drawn in, I was reminded of the curved froe one of my friends brought years ago. It was hand forged, and from the curve I assumed that it was for splitting sap bucket staves. (I did use it when I made my son a canteen for 18th Century reenacting & it worked great splitting pine pre-curved staves.)

Caleb James said...

I continue to find a gem of information in your old posts Pete.

I am going to get some beech soon and start splitting out parts for making molding planes, etc. so trying to decide how to approach it. This and other post you have on the subject are helping shape my approach.

Thanks Again!