humidity, teflon, hell, jon, whateve:(Was Tapping Strings)

[A440A@aol.com]

David writes: 
>Ed's example of the hole drilled in high 
>humidity being oblong at Christmas would not prove out, I suspect, in that
> the shape would be created by the difference in dimensional shrinkage of
> the end grain verses across the grain.  The end grain change would be less,
> creating the out-of-round, however, the cross-grain shrinkage would exert
> enough pressure on the teflon bushing to cause the pinning to be 
>excessively tight, requiring easing.  The stuff that was loose in winter
> would probably be caused by previous deformation of the teflon, mis-easing,
> or Satan.

Greetings, 
   I don't think so.  I also have a customer whose piano is fine in the 
winter, yet every summer, there are numerous clicks in the action, plus, the 
springs move the hammers a lot faster in summer. This seems to be the result 
of the teflon being deformed by the summers humidity.  I believe that the 
cross grain expansion is sufficient to distort the teflon, (end grain change 
is realistically nil) allowing this to happen. I have been told that teflon 
has cold-flow properties, which I took to mean it would deform under stress 
and then come back. 
Regards, 
Ed Foote