Is the mast finger jointed or scarphed? A finger joint has multiple tapered
tongues that mesh like the fingers of two clasped hands. In a scarph joint the
pieces which meet end in a single very long taper , typically 12:1.
I've never seen a finger joint in a spar, so i hesitate to advise without having
seen it.

For a scarph joint, it's best if you can disassemble the parts. Abrade the
mating surfaces back to clean wood. If you can't disassemble the parts, the
odds of cleaning out the failed joint are slim and you might consider cutting
out a section of the failed stave and scarphing in a long dutchman. This is a
finicky bit of chisel work.

There are several kinds of glue which can be used for a job like this. For most
boatbuilders these days, the standard adhesive is epoxy. The brand that's
easiest to find is West System. There are others. Get a gallon. You'll use it
elsewhere in the snipe. The advantages of epoxy are that its properties can be
tuned to the individual job, that it'll fill less-than-perfect joints, and that
it does not need heavy clamping pressure. Get the West System book on wooden
boat repair. (about $5).
An older wood spar was probably glued up with something like Weldwood Plastic
Resin glue. This is water soluble, inexpensive and needs tighter fits and more
clamping than epoxy. Also OK but a pain to use is resorcinol. It's a two-part
glue which needs tight fits good clamping and moderate temperatures. Its a dark
red in color and unsttractive in a spar that's to be varnsihed..
Don't use white glue, yellow carpenter's glue or polyurethane glue on a spar.
The PVA (white and yellow) glues creep under load. The polyurethane is just not
strong enough.
Good luck,
Jim

..

The McClunes wrote:

I am slowly rebuilding a wooden Snipe class sail boat. The boat sat in an
old garage/barn for many years. One of the results of age is that the mast
has come apart near the top where it had been finger jointed(?) together.

First of all, is it possible to re-glue this joint?
Second, what should I use? Will Elmer's wood glue hold or is there something
better I need to know about.

Any help will be greatly appreciated.
Thanks!