Strings riding up (was Tuning stability)

[Ed Sutton]

Fred wrote:
> The real thrust of my musing was to consider
> "going with the flow" in real world situations, where recapping or bridge
> replacement aren't going to happen (at the particular moment). "Curvature
> happens." Bridge tops crush at both sides more than on top. This is what we find
> most often in the field.
and
>    BTW, if anyone reading really believes that  light tapping doesn't crush
bridge
> tops, take a piece of wire, lay it on a bit of exposed bridge top (above C8, eg)
> and give it a tap with your brass rod. Even with your hammer shank. Give the
> amount of tap that has "given focus to the tone," "allowed you to see the string
> drop," "dropped pitch 4 cents," whatever. Then look at that bridge top. I
> guarantee you'll see a little groove where none was before.

So, this suggests we should be tapping the string in the middle!

Not near the termination points, but along the arc in the center of the bridge
cap.

If humidity change can crush the wood at the edges to make the curved string
groove, then tapping forcefully in the middle should be able to deepen the groove
in the middle so that the string is not lifted away from the termination points at
the edges.

Would we then reach a point of stability as the crushed wood becomes harder, or
would we just be starting the process over again, so that the next rise in
humidity  would push the edge grooves still deeper?

Let's hurry up and get this figured out, I'll be restringing the next piano in
about 2 weeks!

Ed Sutton