superglue

[Bill Spurlock, RPT]

Gordon:
I don't think anyone seriously believes that any adhesive will adequately repair
a hammer shank broken off right at the hammer head; a long tapered break maybe .
. . . I think the broken shank thing is just done as a demo in exhibit halls,
but clearly there's no longer any continuous grain from the shank on through the
hammer head.

I do find the stuff very useful though. In the shop it's great for quick & dirty
jigs, attaching stop blocks to fences, etc. In the field, it's good for
reinforcing suspect action glue joints and repairing some broken parts:
* laminating veneer onto the sides of broken keys: cut the veneer pieces, lick
them to moisten slightly, apply medium viscosity CA glue to the key, and press
the veneer in place for 30 seconds. (The moisture causes the glue to set up,
eliminating the need for the very smelly accellerator.)
* upright jack flanges breaking loose from wippens: apply a little accellerator
to each jack flange glue joint, then follow with the thin CA glue.
* stripped screw holes: this is one of the best uses. As long as the holes are
not totally stripped yet, saturate with thin CA glue, apply a little
accellerator, and the threads become hardened enough to hold very well,
sometimes even better than original in soft wood.
* attaching rubber buttons: The type of rubber buttons that fit into holes in
the case parts can easily be knocked off if attached with other glues. CA glue
welds them to the case for good. Put a drop of medium viscosity on the end of a
hammer shank (do this off to one side of the instrument), swab the recess in the
case part with it, breath on the rubber button to moisten, and press in place
for 10 seconds.
* One of my favorite uses is for attaching bushing cloth "bow ties" to trapwork
parts. For example, upright damper lift rods, where the pedal dowel pin goes
through a hole. The modern rubber grommets fall apart quickly. You can just
insert two 1 1/4" pieces of bushing cloth, wet one end of each with a little
spit, uh . . .  I mean saliva-based accellerator, apply medium CA to the other
ends, and squeeze them together lightly with pliers (not your fingers!) to make
a quick, permanent cloth bushing  like the older pianos had.

I do not find CA glue to be as strong or as predictable as wood glues or epoxy
for structural repairs though.

Bill Spurlock