A-440/Cracked Plate, etc.

[Dave Nereson]

----- Original Message ----- 
From: "Dempsey Jr., Paul E" <dempsey@marshall.edu>
To: <pianotech@ptg.org>
Sent: Friday, November 12, 2004 7:45 AM
Subject: A-440/Cracked Plate, etc.


> David I. said: "Why don't we ask the List if anyone has had a plate
> crack during a pitch raise.   I've been working on pianos for 30 years
> and it has never happened to me"

    Yeah, I had a Baldwin console plate break on me.  It just would not stay 
up to pitch.  I thought it was because it hadn't been tuned in a long 
time,or not enough, or because the last tuner didn't "pound it in."  So I 
kept pulling 'em up when all the sudden, "POW!!!!!," a rifle shot went off, 
and I probably jumped a foot off the piano bench.  Couldn't stop shaking 
after that.
    What should've tipped me off was that one key started sticking and I 
couldn't figure out why.  Well, a plate strut was cracked and it had been 
gradually bowing out until it contacted the tail of a wippen.
    Anyhow, I looked underneath, and it wasn't the fault of the pitch raise, 
but rather the casting.  There was a small pile of sand directly under the 
break.  Somebody must've kicked part of the mold in at the foundry and the 
sand made a weak spot in the plate web.
    Well, it was still just barely under warranty (9 1/2 years old), so 
Baldwin agreed to replace the plate if the customer would pay shipping one 
way.
    Two other plates have cracked on me.  One had cracked before and someone 
did a poor welding job -- it broke again in the same place.  Another 
developed a hairline crack in a strut, but never fully broke.  It still 
holds pitch at A440 and I tune it every year or so.  It's been 10 years or 
more and the crack has never widened.
    On old pianos, if they need more than about a quarter-step pitch raise, 
I tighten plate screws first.
    --David Nereson, RPT
    --