Cutting Wood (Safely!) With a Chain Saw

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Whenever you cut, be sure the engine and the chain are going full speed when the chain touches the wood. Then let the saw do most of the work. Don't force the saw into the wood. Pivot the saw on the bumper spike. Use plenty of chain oil (pump the oiler every ten seconds to break in a new saw). Keep your body just slightly to the left of the plane of chain rotation. Hold the saw firmly. And don't be afraid. You are in charge.

Bucking

Out there in the woods, we're going to be cutting all sizes and kinds of wood, under various conditions. How do we avoid limbs that snap back and logs that roll? We'd better look at some woodcutting situations.

Plastic or homemade wooden wedges will be useful tools. In many cases, simply using a wedge will save a guide bar from being .pinched in a cut. A pinched bar is often bent so badly that it makes continued cutting difficult or dangerous, so it is definitely to be avoided. If you're going to buck a log that's lying fairly flat on the ground, so that its weight is supported by the ground for its entire length, use a wedge to keep the kerf open enough to avoid pinching the bar (Fig. 4). Or make a series of overbucks, then roll the log over and finish from the other side. Remember to work on the uphill side and avoid cutting into the dirt.

The first thing to consider in any more complicated woodcutting problem is the stress factor. If we analyze the stress conditions before we cut, we'll avoid many problems.

The general rule is first to cut the side of the log where the wood is compressed by the stress, then cut the side on which the wood is under tension created by the same stress. For example, when a log is supported on only one end, the compression of the wood occurs on the underside of the log, while the wood in the upper portion of the log is under tension. On the other hand, if a log is supported at both ends, the compression occurs on the top side, while the tension occurs on the underside. Always stop to analyze the stress before cutting (be especially careful of tree limbs bent against the ground), and always cut the compression side first and then the tension side.

With a huge log supported on one end only, we must minimize the amount of stress at the moment the cut becomes complete. A wedge won't help in this situation because it would increase the stress, rather than decrease it.

So let's start our cut from the underside of the log by cutting upward with the top side of the guide bar (called pulling chain) until we've cut about a third of the way through. Then we can finish the cut from the top of the log, and the stress at the moment the cut is complete will be considerably lessened. The log will be unlikely to split, and the cut end will simply fall free as soon as our top cut meets our bottom cut (Fig. 5). Note that this procedure is made much more difficult, even impossible, if the saw won't cut straight because of a bent bar, an improperly sharpened chain, or unevenly filed bar rails.

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