Glide bolts

[Isaac OLEG]

> We bang on the piano (on the wooden beam that is situated
> against the iron
> frame and directly over the keyboard, what is the name?
> please)

I may say the stretcher

 and listen for a rattle.....
> If we hear a rattle we put one finger lightly on each bolt,
> until we have
> found the one that causes the rattle.
> Tighten bolt, end of story.
>

Rattling noises can well came from other parts too, the front rail too
lightened or badly bedded, or the back rail. You forget to mention we
may push a little on the left pedal for the "banging test" ....

On old pianos we sometime have a rattle then only because  in the wood
under the glide bolts there is an imprint at the at rest position, and
pushing slightly the action to the right the bedding is disturbed
enough to rattle.

I usually level the surface of the wood under the glide bolts before
the beginning of the work.

For sure it takes time to get a precise feel for that. On actions
where we can hold the glide bolt screw, I use my vise grip pliers to
check the extreme ones or the ones I hardly can hold firm enough. Then
it is easier to pull lightly on the screw.

Talking about pressure & sound regulation, while there is a very
definite advantage in sound to have a very even pressure, as the bass
side is heavier, the knocking test may well work easier on this side,
or we may have a bit more if the treble if the tone is better then.
Is it acceptable or evening is necessity ?

Regards and thanks

IZaac OLEG Z

>
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> "where music is, no harm can be"
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