You start the hole for the spike using a VERY small drill bit. Only drill a few hars deep into the neck---just enough so that the model railroad spike can be pushed about a third of it's length into the neck. Then tap it gently down the rest of the way. I should hold nicely that way. If the drill hole is too small you might split the fingerboard. If your drill hole is too large the spike will not stay put.

Art Thieme