Re: WOW it honestly really does happen..........(LP Content)
A properly-done (meaning thin) glue joint is stronger and more dimensionally stable than the original wood itself; that's common woodworking knowledge. And it is right on the weakest spot of the neck, because it is right where the break occured. There is a very good reason that traditional guitar construction calls for a scarf joint on the head (which is basically just a neat version of the joint you get when you repair a broken head). Efficiency of use of your materials is one reason (no need for thick lumber), but strength is another. And volutes are right there with scarf joints. The invention of Gibson's one-piece, no-volute neck design was based on manufacturing considerations, not on high-end guitar making practices of the time. It works, and it looks good. But it does have it's compromises. And, of course, when Gibson finally did start making their guitars with volutes, they put them in a less-than-ideal spot and made them uglier than sin, so there was really no point in it.
Another point is that you don't need anything stronger than wood glue for the above mentioned "properly done glue joint." Epoxy is overkill. It's way stronger than needed, it's less plastic, it's more expensive, it's more toxic, it's harder and messier to work with and to clean up, and it is practically non-reversible, which is a bad thing when it comes to building guitars. You want most joints to be fairly easily reversible if possible.