Rebushing S&S Damper Rail

[Paul]

Willem

Here's what we did:  we drilled a few test holes in a scrap the same
thickness as the guide rail. These holes were not tapered as were the guide
rail holes, which didn't affect our technique or outcome. Remove the old
felts and clean the holes. If the bushings were glued in, drill them out
with a bit size that  just cleans the old glue. A drill press at high speed
works best

Nameboard felt was the first layer and bushing cloth the inner layer. Both
were red. We couldn't locate a black colored felt of suitable thickness. Our
gauge was a #7 bridge pin. The felt was cut in strips about 4" long to a
width that would fill the hole snuggly without bunching. A wedge cut off the
end formed a "needle" for easy starting. The outer layer was pulled about
half way through then the inner layer was started and pulled to be slightly
proud of the outer one. Then both felts were pulled and stopped to be
slightly proud of  the top of  guide rail. This formed a nice collar to hold
the bushing. The technique will come to you quickly. The bottom was trimmed
with a new razor blade, slightly proud of the bottom of the guide rail. We
worked with about a half dozen strips at a time, pulling them all through,
trimming, then repeating the process. The bridge pins were inserted and  the
new bushings were dampened with water/alcohol solution, then dried with a
hair dryer. This treatment gave the felt a "set" and laid the felt nap down
to give the damper wires a very smooth and consistent surface. Caution! Too
much alcohol solution will damage the guide rail finish. No gluing was done.
It was easy to get the bushings uniform in height above and below the guide
rails by clamping them so the holes were horizontal and the top and bottom
could be eyed. We discovered that the inner felt would lay the nap down in
one direction  of both felts and pulling became easy in one direction. Any
mistakes had to be pulled out and threaded again. Working with short strips
kept from fraying the felt and keeping it snug in the holes.

I'm not sure if we reamed the original balance holes to accommodate our
felt. I do remember doing it on another job with improved results and very
pleasing appearance. If you need to do this, use a numbered drill index and
step up sizes on at a time. It's amazing how 1 or 2 thousandths changes the
fit of the felt. Run your drill press at high speed to prevent tear-out. Any
size change was tested in a piece of scrap with the felt and the bridge pin
gauge to determine the proper clearance. The #7 pin suited the damper wires
for this piano.

Our results were very satisfactory in function and appearance. We've done
only one double felt guide rail, but many single layered ones with this
approach, and no gluing speeds it up and keeps it neat. To date no service
calls to replace a bushing. The felt nap and collars top and bottom do a
great job of securing the cloth. We estimate about 2-3 hours for a complete
job.

 Let me know if you have any trouble or can improve on this technique.

Paul Chick
----- Original Message -----
From: <Wimblees@AOL.COM>
To: <pianotech@ptg.org>
Sent: Tuesday, September 26, 2000 9:17 AM
Subject: Re: Rebushing S&S Damper Rail


> In a message dated 9/26/00 7:12:46 AM Central Daylight Time,
> tunenbww@clear.lakes.com writes:
>
> << Paul
>  We just did one of these and found a combination of nameboard felt and
>  bushing cloth to work. We drilled some test holes in a scrap the same
>  thickness as the guide rail to establish the required sizes of cloth and
>  devise a technique for pulling the bushings. It turned out to be an easy
>  job. BTW we did not glue in the bushings. I can give you more details if
you
>  need them.
>
>  Paul Chick >>
>
> Paul
> I had been meaning too ask for more details on how to bush a S&S damper
guide
> rail Would you please share with us more details on your procedure.
>
> Thanks
>
> Willem
>