Felt Warning

[Maxpiano@aol.com]

Ken-

I've seen this and had strings break occasionally in old uprights, notably
Lesters.  The particular location is in the felt wound around the nonspeaking
length of strings in the treble (counterpart of stringing braid).  Long before
the days of synthetics.  The reason, I am told, is that the acid used in the
felting process was not entirely washed out during manufacture.

Does anyone know whether all the felt we buy from suppliers is acid-free?  Any
way to check?

Bill Maxim

In a message dated 9/11/98 12:36:57 AM Eastern Daylight Time,
kenrpt@mail.cvn.net writes:

<<      List, I recently serviced a nice Yamaha C7 where someone had muted off
 an offending section of front duplex. As I was doing some regulation,
 voicing, etc., I took it out to see if it was necessary. The entire area
 where the felt was crusty with rust. The felt looked like what is
 commonly referred to as nameboard felt. I don't know what percentage
 synthetic fiber is in that stuff, but it was enough to hold in the
 moisture, and do some damage. The piano is only 12 years old. It may be
 common knowledge, but please make sure to use only 100% wool felt against
 strings. Is there any way to tell when felts are part synthetic. Aside from
 seeing if they melt when you burn 'em :-)
      Ken Jankura
  >>