This is one of the times that the cautionary rules explained above did not go as planned. As bill was cutting the first side of the tube, it was noticed that the kerf was closing behind the blade, making backing out of the cut impossible. The solution was to drive a thin wedge into the kerf to prevent it from totally closing, and continue cutting entirely through the first side of the tube. Note two things: the tiny wedge on the first side of the tube, and that Bill is sawing his way OUT from the interior of the tube.

Photo by Bill Liebman