Tuning peg, Breedlove six string

Q: I broke out a bit of wood from an ebony mandolin bridge between the two E strings. A tiny, perfectly square piece split and popped away somewhere, maybe a 16th or 32nd of an inch deep. The E strings buzz now since this tiny bit of material flew the coop? The missing material is just the amount of ebony between the E strings on the bridge. I was thinking of trying to fill the void with marine tex or some other type of epoxy?
Thanks,
Wendelin

A: The only replacement material you should consider is ebony. Any lutherie will have lots of little pieces of ebony; cut offs from guitar bridge blanks, fingerboards, violin pegs etc. I have a box of such pieces. Get a very sharp knife. An Excel, available at craft centers or hardware stores is best. An Exacto #11 will work, but not as well.

Carefully, square up the bottom of the gap. Then, widen the gap beyond the notches for the E strings. You want the strings to be resting on new wood and not on the glue line between the new and old. Cut and fit a piece of ebony to fit snuggly into the gap. The bottom and ends should fit perfectly. The sticking out part should overhang in all directions. The excess will be shaved off after the glue dries. Make sure the grain of the replacement wood is going the same direction as the old wood. The grain of ebony is much less obvious than the grain of other woods.

The perfect glue is black epoxy. It dries slowly, so it capillates deeply into the wood, and dries very hard to carry vibrations well. The black color blends with the black of the ebony. Clear epoxy will "lens" any gap in your joint, making it look bigger than it is. If black epoxy or clear epoxy with nigrosine coloring powder, can not be obtained, any wood glue will work fine. Clamp it, wipe off squeeze-out and let it dry overnight. I then use the sharp knife, and various files to shape the patch. The final finish is a rubbing with steel wool. I then mark the wood with the knife and use a .013" gauged file to cut the new string slots. Your E strings are either .010" or .011." Cutting to .013" gives them some breathing room. If you have no fancy, expensive files, all this work can be done with your sharp knife. You can even do the final finish by scraping with the sharp edge. Here's a fun fact: Sand paper was not available until the 1800s. All the Stradivarius violins were scraped to a lustrous shine. Remember that the string slots must slope very slightly toward the tailpiece so that there is a clear contact point at the fingerboard side of the bridge. Just loosing the wood between the strings would not necessarily make them buzz.

Steve Mason