ive experiened the same on old #12 some yrs ago,i tried carpenters wood glue ,but i think the brand (gorilla glue) is much better,but you want to moisten the area w/water firstand work the glue into the crack,then sqeeze the area to see if glue squirts out and if so, apply some more and then clamp but not too tight to avoid cracking the area, and wipe off all ecess glue and let sit for at least 8 to 12 hours,it worked for me and it wont cost what a luthier would charge .