[pianotech] PVC-E and keytops

[Jon Page]

I use PVC-E glue for keytops as many techs do. Maybe your first set failed
because the glue wicked into the porous keystick and the joint was starved.

After planing to develop a clean surface and attend to reestablishing
overall keystick height (to maintain a relation with the sharp) apply
a sizing coat of glue to the key. This will keep the glue from wicking away
and maintain a bond.

Clamping is usually not needed after a firm mating. If you are using tops
with the fronts attached and they don't mate well at the front then clamping
is needed. A rubber band will suffice for the front with a slat and 
spring clamp
for the top.

If there is an extended shoe on the bottom of the key, the elastic can be
placed around the back of it and stretched to the front. Otherwise, place
the elastic around the key (top to bottom) at the back of the button; cross
the bands under the key and stretch to the front. Certain applications
may require the additional use of a push pin somewhere strategically placed.
You want the pulling force to approach the front from the bottom in an effort
to draw the plastic unit downwards. Apply slat and clamp the top.
-- 

Regards,

Jon Page