Wooden action parts and frames

[Phillip Ford]

>I expect aluminum flanges would be some noisier, especially as the felt
>(bushing) takes on compression-set over the years and leaves room for a
>slight amount of slop. Wood is inherently a better damper. Though, I
suppose
>the argument could be made that the transmission path is so short between
>the flange tongue and the edge of the rail that there would be no
practical
>(audible) difference.
>
>On the other hand, how often have you come across hammer flange screws
that
>were slightly loose. Enough that the flanges had to be moving slightly
each
>time the note was played. Yet there was little or no audible clacking or
>clicking. I expect there would be some of both with an aluminum flange.
Of
>course, on yet the other hand, without the expanding and contracting wood
>fibers the screws might not loosen up in the first place.
>
>Del

It was my thought that the screws might not loosen in the first 
place.  This, and the fact that the metal would not move around causing the bushing to get tighter or looser, were the reasons I thought there would be some advantage to it.  I suppose it would be easy enough to install a few on a sample piano and find out.  One thing I'm not sure about is sizing the bushing in the metal flange.  I'm not sure how bushings are normally installed or sized.  I believe the way Renner does it is to string several bushed flanges on a wire of some appropriate size and soak them in a solution (proprietary?) for some period of time and then let them dry on the wire.  Perhaps this is only sizing the felt and so the same thing could be done with the metal flange.  If it is also sizing the wood then the result might not be the same with a metal flange.

Phil F



Phillip Ford
Piano Service & Restoration
1777 Yosemite Ave - 215
San Francisco, CA  94124