Identify the source of the crack, such as one in the handle, on the end of the bat or in the barrel of the bat. Separate the crack as carefully as possible with a flat-head screwdriver and leave the screwdriver wedged in the crack.
Apply a generous amount of wood glue inside the crack. Ensure the glue gets into the crack by using your fingers to rub the glue into the crack.
Remove the screwdriver and apply the clamps to the crack. Use an old rag to wipe away the excess glue. Let it dry for at least three hours or overnight for best results.