Sleek
in post 32 above, Dan identifies four different causes that could induce set. One that he mentions is "Early growth break down between growth rings". Having that single early ring in the center of the limb may bring out the type of failure he mentions. This is often described as a failure in "shear" by engineers, and not uncommon in certain beam configurations.
My interest in this inquiry, is that it would be nice to be able to learn how to identify the different types of set as they rear their ugly heads while tillering. Perhaps letting us know whether the stave needs heat treating, a better back, just more time drying, or an early retirement.
