Soundboard cracks

[A440A@aol.com]

 Greetings list,
Rob wrote;


>         I've been working with this problem for some time: I've done a
> soundboard separation repair and I have a crack to fill on the board
> itself. Some can be done using maple wedges, but smaller, more
> elusive cracks I fill with a G2 epoxy (fairly elastic but strong,
> used for laminating tennis rackets or X-country skis.)

      It would seem to me that a fairly elastic glue would not be appropriate
for a soundboard, as it would increase the damping.  This may be purely
academic on a small crack or two,  but board-length cracks and separations
may require enough material to make a difference.
      Glues used in the wooden soundboards of musical instruments should be
as acoustically "transparent" as possible. I believe that Steinway still uses
hide glue to lay up their soundboards.
      There is a   difference in the impedance of a joint that has been
epoxied together, and one that has been glued with hot hide glue, or ( as
Willis Snyder proposes), Resourcinol.
     Also,  can you explain the use of "maple wedges" ,  as I would not
expect maple and spruce to get along very well.

Regards,
Ed Foote
Precision Piano Works
Nashville, Tn.