I've always admired the short sapling bows that John Strunk would create from various woods such as vine maple, service berry and hawthorne. They look like they should be so simple to build. Just split the stave down the middle and tiller the belly until a bow materializes - no fades, handles or shaping of the limbs required. But looks are deceptive. Lateral and vertical pin knots, bumps, dips, and a high crown that wanders from one side of the limb to the other are enough to make any sane bowyer throw their arms up in despair. I've attempted three of these bows in the past, two of which were utter failures, and one which survived, but I was not satisfied with. A couple of weeks ago I decided to torture myself again and attempt to fashion a bow out of a hawthorne sapling. I have spent hours looking over John's sapling bows trying to decipher the techniques for successfully building such a bow and this time I was determined to apply my observations.
The first observation is that you must faithfully follow the back. If the the back dips, so must the belly follow. If the crown wanders to the left then more wood must be taken off from the left. The second observation is that pin knots can be deadly unless handled properly. If a knot (particularly one that is lateral) is ignored, it will likely result in a cyrhsal if in a high strain area. It should be left proud, but not too much or other areas may become overstressed particularly when there are many such knots in close proximity. Finally because the limbs are typically narrower than one would normally design with the same wood of larger diameter and the presence of a high crown, you must be very thoughtful about the tiller to ensure the compressive forces on the belly are distributed as evenly as possible - there is very little room for error.
In the past couple of weeks I have attempted to apply these observations, though clumsily at times. A serviceable bow has emerged from my efforts, but more importantly my understanding of tillering has grown substantially. One thing is for certain, I'll never look at sapling bows and those who successfully create them the same again.
