[pianotech] Kimball Spinet with HEAVY Sponge Action

[Terry Farrell]

I was stumped this morning (and still am). I went to tune a 1960s (or so) Kimball spinet this morning. Sat down at the piano and struck a big cord with both hands. YUK!  Totally weird action. Felt like someone dropped a four-foot long sponge down into the action. ALL keys move heavy initially, and then resistance keeps increasing as you push down. Piano clearly hasn't seen a regulation since it left the factory (assuming it was regulated then) - but that wouldn't explain the heavy sponge action. It has excess lost motion, let off is 1/4", etc., etc., but nothing to explain the spongy action. Looked for split rails, any action components way out of whack, but didn't see anything unusual.

The only thing I could think of - and I don't know if this is even possible - is the crusty/crunchy rubber nuts for the drop stickers (is that what they are called?). They are all real hard and I suspect they will crunch up right quick if you tried to remove one. I wanted to to isolate action & keys, but didn't have any spares with me, so I didn't as I knew they would crunch apart.

When the key is depressed and the rubber nut and drop sticker rise, the angle that the drop sticker makes with the key changes. If the rubber nut is very hard, I guess it would tend to resist that angle change as the key is depressed - AND it would tend increase resistance as the key is depressed.

BUT, that angle changes so little - seems hard to believe that it could have THAT much effect.

With the lost motion available, I checked action freeness as best I could and it seems very free, as do the keys (what I could tell).

Anyone have either an opinion on whether it could actually be hard rubber nuts causing the heavy spongy action, or any other ideas???????

Thanks!  Hey, maybe this will at least make a good puzzler!

Terry Farrell