[pianotech] singing sustain, what to do?

[Bruce Browning - The Piano Tuner]

Mike,
Try talc or teflon powder on the felt.
Bruce Browning
The Piano Tuner.

>Here's what I
> think is causing it:  the lift tray is aluminum, the felt is soft and
> thick, and the tray pivot is nowhere near the underlever centers.  So
> when the tray is lifted, the underlevers slide on the felt, playing the
> aluminum tray like a violin.  What to do?