Bolt strength

[Delwin D Fandrich]

----- Original Message -----
From: "Farrell" <mfarrel2@tampabay.rr.com>
To: <pianotech@ptg.org>
Sent: September 21, 2001 4:19 AM
Subject: Re: Bolt strength


> .... I did a Baldwin Hamilton a while back with a 1/2" to 1" separation
> across the entire back. It was a lot of work bringing it back together
with
> the ten clamps - and that was with tension down two full steps, and I did
> not quite get it completely back together - but at least the damper were
> rising from the strings (that was the original complaint from the
customer -
> the plate was so bent over, the dampers were not able to lift from the
> strings!).
>

Your use of multiple clamps is well advised. Many vertical plates are rather
weak along the top of the pinblock. Too much clamping force in just one area
could be a problem--as in a broken plate.

You'll rarely get one of these things all the way back together. The longer
the gap/separation has existed, the harder this will be.

Which is why you use a combination of bolts and adhesive to hold them once
you give up on the notion. It's also why I use epoxy. In the end, when
everything is cured, I can grind off the excess and at least it looks like
there's no gap left. Ron's point is well taken, though. Titebond will
generally do the job and it's much less messy. And, if you're concerned
about leaving a visible gap, you can always shim the thing.

Del