Doing crack

[larudee@pacbell.net]

I'm working on a 1993 Yamaha G3 that has two cracks in the soundboard.
One goes all the way through the board, and I'm going to shim it the
standard way, using the Spurlock method.  The other doesn't go through -
and here's the strange part - it's from the bottom and doesn't show on
top.  It's most visible between two ribs, but I can slightly feel it
forming on the other sides of those ribs as well.  On the other hand,
there is no failure of the glue joints between the ribs and the board.
Any suggestions for repairing the second crack without having a second
shim show on the top surface of the board?  This type of work is not a
large part of my business, so perhaps this situation is more common than
I think to those of you who do a lot of rebuilding.

Paul Larudee