"pounding"

[Brian Henselman]

I dunno, Ron.

But even the best hammer technique on the world is wasted when the board is
being loaded up with pressure.  I recommended getting to full tension ASAP
without concern for test blows or finessed hammer technique.

Then remute, retemper with modifications to allow for additional board
squishing if applicable, and retune unisons, with some good test blows and
proper hammer technique.

Test blows before your up to tension is just wasting your ears, and test
blows while its still muted is wasted time also.

Cheers,
Brian Henselman, RPT
musicmasters@att.net

-----Original Message-----
From: Ron Nossaman <nossaman@SOUTHWIND.NET>
To: pianotech@ptg.org <pianotech@ptg.org>
Date: Tuesday, November 02, 1999 9:04 AM
Subject: Re: "pounding"


>There's something else here that I've noticed that hasn't been addressed.
>When doing a quarter semitone or more pitch raise on some pianos, an odd
>thing happens in the high tenor and treble on the second pass. After a
>string is tuned adequately, often a sharp rap will knock it down about
>three or four beats. It will only do this once. Further pounding has no
>positive effect, and a quick check will indicate that the other two strings
>have settled too. The immediate response of pitch change from tuning hammer
>movement prior to the sharp blow indicates that it is NOT coming from
>unequal segment tensions forward of the bridge, so it is definitely NOT a
>hammer technique problem. That only leaves two possibilities that I can
>see. The first is that the coils spontaneously settle around the pin and
>the pitch drops accordingly. I guess this is a possibility, since it's easy
>enough to demonstrate how drastic the pitch drop can be by tapping directly
>on the coils, but I can't see the shock of a hard blow going past at least
>two bearing points and arriving at the tuning pin with enough power to
>settle the coils. That would seem to leave possibility number two, which
>looks to me to be considerably more likely. That is that the strings render
>through the bridge, more nearly equalizing tension between the speaking
>segment and back scale. That would also explain why this is much more
>noticeable with a big pitch change, than with a minor one. I assume it
>happens more in the high tenor and treble for two reasons. The total string
>length from the rear bridge pin back to the hitch is greater in proportion
>to the length from the front bridge pin to the tuning pin in this area than
>it is further down the scale. That means there is proportionately greater
>elongation potential in the back scale, so more string can render across
>the bridge to "equalize" (though it's highly unlikely to be exactly equal)
>tension in the segments. Also, a little string movement makes a bigger
>difference in pitch in the top half of the scale than in the bottom half.
>
>In defense of this idea, note that when doing a pitch lowering of over a
>quarter semitone, pitch often tends to drift slightly high in these same
>areas as you tune the second pass. That would be the higher tensions in the
>back scale slowly pulling the string sharp as it renders across the bridge.
>Pounding does no good whatsoever when doing pitch lowering. Didn't you ever
>wonder why, when it is often the only way to get a pitch raise to stay put?
>When pitch lowering, I find that hitting them fairly gently, but in rapid
>succession, and a lot of blows, will settle them better than anything else
>I've found. If you keep them moving, they slide better.
>
>All this also indicates to me that one can't state with any certainty that
>hammer technique alone will take care of this problem. I would say that at
>least one fairly "firm" blow per unison, at pitch, is absolutely necessary
>when pulling a piano up to pitch. Dropping pitch, or tuning something that
>is already at pitch is a different story.
>
>
>I know that I'm the only guy on the planet that thinks strings render
>across bridges, but I don't account for my observations any other way.
>
>
>
>Ron N