Cracked head stock

thats an unfortunate thing you got going on. by string t i assume, you mean a retainer to increase tension across the nut? if so, then you could easily have cracked you headstock applying it. for future reference, in case what i suspect to be the case has happened, you should pre-drill your holes. and if the neck is maple, then even more so.

 

About the only fix at this point would be filling the crack/hole with titebond. If the area is dark get some of the dark wood titebond, it hides fairly well. Glues now days are stronger than the wood itself.
It's not the best solution but it would be better than nothing since vibration and stress could cause the crack to get worse.
And yes it could be if you didn't predrill that might have caused it.
Good luck,
Dirk

 

No, that is only cosmetic. Personally, I would get water-thin consistency superglue, and wick it into the crack (capillary action) to ensure that it stays put where it is and doesn't progress. How big / long is the crack? Is it at the exact spot where you're putting in the string tree? If so, you could also water down some titebond a tad, and fill the screw hole then use the tree's screw to "force" the glue-slurry into the cracks...it's almost as effective as the superglue, and either should work well.

 

i must say, though i hadn't thought of it, filling the crack with glue and clamping it as tight as you can (preferably using pads of some sort not to damage the headstock) would probably be an effective repair. after that, then a laminate would be an added bonus, and would make the damage invisible. also, if you have any doubt whether you cracked it or not, then you probably did not predrill a large enough hole. also, if you can, pre-threading is a good idea.