key bushings

[Baldwin Yamaha Piano Centre]

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>Hi Isaac,
>I usually leave the cauls a few hours, but noticed that the sizing is not 
>as stable as I like sometime.

I have also noticed the same thing on field repairs using PVCE glue, some 
times get a recall for a sluggish key.

>
>But as I use most often heated brass cauls, I guess the drying is faster 
>(in surface anyway)

Bin thar done dat.  Still do it if I'm in a hurry.  Usually on a rebuild, 
we do every thing that is needed to the keybed, then the action analysis, 
to determine what parts to order.


I think the big area of movement, is the reaction of the water in the glue, 
on the key button. Leaving them a couple of days, we have found no sizing 
is needed on the bushings, only sizing the balance rail hole.  This we size 
with a polished balance rail pin, chucked in a battery operated drill, one 
quick pull of the trigger, and the hole is sized to perfection.  We size 
from the top down.  No guess work as to where the friction is coming from.

Key bed fitting, friction control, and key fitting, is perhaps one of the 
most neglected jobs in our craft.
Regards Roger



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