Sometimes wood breaks. In the old double-hung window repair world, this most frequently happens on weight pocket access doors. Occasionally jambs are made from boards with squirrly grain, or previously unopened weight pocket doors have kerfs cut through knot holes. When this happens, the pressure exerted to snap open the door can result in breakage. When you’re in the field there isn’t a lot of time to glue and clamp a broken board so we often use super glue and super glue activator. This practice only takes about ten seconds to cure and leaves a solid bond.
Some people think of dry rot as unprotected wood that has been exposed to the elements and contains large checks. This wood is usually still structurally sound. The checks can be filled and the fibers reinforced to save the wood. We think of dry rot as powdery or mushy (so in this case not really dry) wood that is no longer viable. This substance must be removed and replaced with new wood fiber in the form or a splice or dutchhman, or entirely new component — or filled with restoration-grade epoxy. The examples above show wood with a degraded finish – not dry rot. The wood fiber is still in good shape, it just needs refinishing.