I received a guitar for repair yesterday that I have mixed feeling about. It is an inexpensive (Dean) acoustic that has a crack starting at the bottom of the nut slot that has propagated about 1" toward the body of the guitar.
The crack is closed under string tension. I loosened the strings and the crack widens when moderate pressure is applied to the face of the headstock but closes up when pressure is removed. Tuning is stable. The guitar has other issues resulting from mechanical trauma in other areas (cracks in top and sides)
I'm inclined to leave the crack alone at the moment because I can't open the crack enough to flow glue far enough into it to make a sound structural bond. The neck appears stable and - short of another blow to the headstock or prolonged exposure to heat - I don't think the crack will get any worse. If it does - a proper repair can be.executed at that time.
Will get photos posted later today.
Thoughts and suggestions would be appreciated?
First - thank you all for sharing your knowledge and excellent suggestions!
I finally had time today to take some photographs of the crack on both sides of the neck. It is a pure crack and not the scarf joint opening. The scarf joint on this guitar (Dean brand) starts behind the nut about 1/2" from the E string tuners and extends to the middle of the headstock. The crack starts at the front edge of the nut slot on both sides.
I'm going to pull the nut for starters and it appears that I can spread the crack to about 0.020" opening with light pressure. More to follow as I get into this repair.
After pulling the nut, it appears that the crack extends all the way across the nut slot at the fingerboard. Glue of unknown origin used to roughly glue in the nut (which came out easily. Cleaning up the mess.
The condition leads me to believe that the crack may have occurred when someone removed the nut without properly supporting the head of the guitar. I use fret nippers and a rocking motion, FTR.
I'd personally clamp that at the second fret (with something hard) between the clamp and neck/fretboard (obviously) and gently work some glue in. It looks exactly like the repair I did recently. You'll get a good solid join there!
I was a bit sloppy on this fix as it was my own (very inexpensive) guitar and I'd take more care over a customer guitar but you get the idea. So long as you don't snap the headstock off, your guitar will glue up fine...
Again - thanks for all of the thoughts and ideas. Here is what I decided to do (drawing from many of your comments).
Photos attached. Again, my profuse thanks to all who contributed.
and a few more pics
Should work a treat :)