Gluing sound board cracks back to ribs.

[Ron Nossaman]

Hi Ric,
I used to rebuild a lot of upright players, and have dealt with a whole lot
of patches just like what you're looking at in field repair situations, so
I have a couple of suggestions.

First, don't even consider the toggles. I've never used them, but I've seen
the aftermath where others have. Just say no. 

Here's how I always did it. Slide a thin spatula (hacksaw blade is pretty
thick, and has TEETH) between the rib and panel. Drill a 5/32 hole through
the rib until the bit hits the spatula. Insert the tip of your glue bottle,
or hypodermic with the needle removed, and force (Titebond) glue into the
hole until it oozes out under the rib. Spread the glue around under the rib
if necessary with the spatula. Insert a 1 1/4" x #6 drywall screw and
tighten it down until the panel is sucked back to the rib. Mop up squeeze
out and present bill. If you DON'T drill a pilot hole through the panel,
the screw will have plenty of bite to do the job. In fact, you usually
don't have to countersink the hole in the rib. The screw will hold in the
panel well enough to pull the bugle head down to not quite flush, but good
enough. Drywall screws come in a couple of different flavors depending on
the manufacturer and intended usage. The ones with the shallow threads are
fine for hanging drywall, but they are likely to pull out of a spruce
panel. I like the ones with the deep threads, and I like the #6 because I
don't want any bigger hole in the rib than is called for. The only reason
the screws are even there is to minimally hold the parts together until the
glue dries, so you don't need to install giant hunks of hardware, and you
don't need tons of clamping pressure.


Ron N