Sunday, 31 December 2006

Splitting Wood

Due to visitors I don't have an opportunity to go into the forest whenever I want right now. This does halt the progress on most of my projects. To weigh up I have translated one of my former articles to English. It is partially overlapping with the "Elm Bow" project.

Splitting wood is a task often needed by the primitive, especially in the construction of bigger equipment like bows and skis. But it is also useful when making something as simple as a drill. The are are to my knowledge two methods for splitting a tree: Either by pounding in a wedge into the wood from one side or an end of the piece or by chopping into the wood and splitting the piece by breaking it out of the main piece. The last method is particulary useful when you are splitting off a smaller piece of a bigger tree or when you don't have an axe.

With a wedge

To split a bigger tree to get several pieces this is the only method. For a start, an antler wedge is pounded, usually in the end, to start the crack. If the tree is small one can usually continue the split by simply seperating the two sides. If the crack shows a tendency towards running of to one side, it can be corrected by directing pressure towards the thickest side. On thicker trees this is harder to accomplish, but the problem itself is usually rarer too. By using a fork in a standing tree you can easily put leverage over on the thicker side. It does of course not work on overly large trees, but instead of just small trees you can with the aid of a fork also do the medium sized ones. If one wedge wasn't enough to make the crack go completely through the tree, pound in one from the opposite side. To make sure you get an even split, pound wedges into both sides of the crack. To save strain on your antler wedges, use wooden wedges for anything but the initial split. Below: Starting a crack from one end of the piece.

If one's plan is to split the log into even smaller pieces, one can halve the pieces the number of times needed to reach the desired size. It does however become progressively harder for every time you halve them, to keep the crack from running off to one side. Sectors are harder to halve than pieces square in cross-section. Because of this, it can be very advantageous to carve the sectors to squares to make the results more reliable. Below: The principle of guiding the crack. The thicker arrow indicates where the majority of the force should be excerted.

The same principle in practise: By using the forked tree additional force can be laid on the thicker left part.

Without wedges

This metod is difficult to explain by text only, but it is, as mentioned, very useful if you have few tools available to you. Especially if you don't have an axe. Start by sawing (with a biface for instance) halfway through the tree or branch while it's standing. When you are finished sawing you use your hand and pulls or pushes in the direction of the notch you have made. This should make the wood split in the deepest portion of the notch and you can guide the split up the tree/branch like described above. If you have no tools you can still do this if you very carefully break the sapling into the middle of it and continue as above.

If you don't need the whole tree, but you need a broad and flat piece, you can take the more ecological approach by splitting out a piece of the trunk without cutting down the whole tree. I rarely use this method, and it does require quite good tools. Make a cut into the tree in the upper and lower end of the piece you want to split and hammer an antler wedge into either or both of the notches to pop it free from the main trunk. It is an excellent method for splitting bowblanks out of large trees (for low crowns) and will often not kill the trees themselves, especially if the trees are conifers.

To most purposes you want as straight grained wood as you can get, I will because of that mentioned a few guidelines for seeing whether the grain is straight before you cut down the tree itself. Some species are generally more straight grained than others. Examples of these are spruce and pine. A wood notorious for it's twistedness is rowan and I have to this date yet to find a piece that was perfectly straight grained. It is easier to find straight grained wood growing on flat ground and in dense stands.

There are in general three signs, on which you can see whether the tree has straight grain or not:

  • Is the trunk straight and even? If not, chances are the grain itself isn't either.
  • Do the fissures in the bark go vertically towards the ground rather than spirally? That is a good sign as the bark usually has the same direction as the wood behind it.
  • Are the branches aligned vertically on top of each other. If the wood is twisted, the branches are often placed in a slight spiral on the trunk.

Illustrations will be posted tomorrow. Happy New Year!