False Beats in high treble after stringing

[Ron Nossaman]

>Just finished stringing my Wing and Sons upright piano project and have 
>quite a few false beats in the last two octaves of treble in single 
>strings.  My first restringing project.  Phil Bondi suggested that I ask 
>on-list for advice.  The treble bridge seemed (to me anyway) to be in 
>pretty good shape.  About 1/3 of the bridge pins were loose and I had 
>removed and replaced after putting epoxy on the ends of the pins.  Also a 
>little epoxy whereever there appeared to be any hints of small cracks near 
>the pins.    Great results, except in certain strings of the high treble. 
>Other than there, the piano sounds great.   I don't see anything different 
>about these strings or the bridge from other strings, but I think I need 
>to fix if possible.  For example, B6 center string has a beat of about 2 
>bps.  Not as loud as a real beat between two strings, but still 
>THERE.   Some higher strings beat faster.

Did you epoxy all of them, or just those that seemed to be loose? When you 
epoxy or CA bridge pins like this, you need to do them all, and thoroughly. 
You need enough epoxy to soak into the bridge cap and fill the gap between 
pin and cap. The bottom of the pin isn't terribly important, just the part 
where the pin enters the cap - where the string is. Otherwise, the "still 
tight" pins will prove to be loose enough to produce false beats with the 
nice new strings. The "best results for the work" way to approach this is 
to pull all the pins, clean up the notches with a chisel, and epoxy in new 
pins. The "least work for the results" method for old uprights that need 
more work than they are going to ever get is to apply epoxy around each 
original bridge pin and heat it with a hair drier or heat gun so the epoxy 
thins and wicks down into the hole around the pin - or use CA, also with 
the original pins in place.


>I have experimented with seating the strings with my copper rod, at each 
>bridge pin.  Also tried tapping each bridge pin in a small bit.  Doesnt 
>seem to help, except in certain strings.  I did lightly sand and buff the 
>v-bar before restringing, and think I have the right adjustment on the 
>pressure bar.  I've been reading the archives and the PTG CD articles re 
>false beats, but the number of "hits" for this search term is overwhelming.
>
>Can anyone offer me advice on what to do next to reduce the false beats, 
>short of unstringing and recapping bridge, etc?  I would appreciate your help!
>
>Frustrated in Florida,
>
>Dave Smith
>SW FL

As an after the fact disappointment balm, try putting a drop (or two, as 
necessary) of thin CA at the base of the speaking length bridge pin of one 
of the false beaters. If you like the results, proceed carefully with the 
rest, and try not to bury the string in CA.

Ron N