glueing controversy

[Delwin D Fandrich]

Frank Weston wrote:
> 
> Delwin D Fandrich wrote:
> 
> >
> > I've also used shrinkable Teflon tubing on a number of set of Steinway
> > type repetition springs. It’s a very reliable method of permanently
> > lubricating this friction point. And I do mean permanently. The spring
> > setting is much more reliable and consistent. It is not necessary to
> > clean out spring groove in the bottom of the repetition lever beyond a
> > quick wipe with the tip of a pencil. In fact, half the time I don’t even
> > do that.
> >
> 
> Del,
> 
> Pray describe this technique in greater detail.  Where and how is the
> tubing mounted?
> 
> Frank Weston

------------------------------------------------

Frank,

Years ago I came across a Steinway action that was sluggish enough that
it barely worked. I "dry cleaned" the action centers, i.e., I tried
naphtha first. That was marginally successful. Then I took the action
outside and juiced everything with (are you ready for this?) gasoline.
I’m not sure which of the two treatments was most successful, but the
end result was that I was able to free up the action centers. I did all
the other work to the action that was scheduled and then tried to
regulate it. All went well until I got the repetition springs. I simply
couldn’t get them to work consistently and smoothly. Finally, I got the
picture and examined the grooves on the underside of the rep. levers.
They were fairly rough, full of Lord only knows what all kinds of junk
and had a decided groove worn in them from the rough surface of the
spring. I considered replacing the springs. I considered replacing the
wippens—not such an easy task in those days, the replacements would have
had Teflon bushings. 

Then I remembered the shrinkable Teflon tubing I’d used during my visit
to my Uncles airplane patch in Thailand. I tracked some down at a local
industrial electronics distributor. I simply took one of the springs
with me and purchased the smallest diameter tubing that would fit. I had
to buy quite a bit. It came in strips about 18 inches long.

I took my newfound treasure back to my shop and tried to work out a
procedure to put it on the spring. What finally worked was to simply
unhook the spring and slide the tubing over the end of the spring so
that the entire curved end is covered and a bit of the straighter
portion of the spring behind the curved bearing surface—use about 15 mm
of tubing is used per spring. I use a small side cutter to trim the
remaining part of the strip flush with the end of the spring. Once the
tips of all 88 springs are covered I simply heat them with an industrial
heat gun. Teflon tubing shrinks at about 350° or so, if memory serves.
You want to get the tubing hot quickly so that you don’t heat up the
entire spring. The tubing shrinks down and grips the end of the spring
tightly. Once shrunk, it won’t slip off easily.

Notice, I’ve not said anything about cleaning either the spring or the
groove. You may certainly do so if you wish, but I have found that it’s
really not necessary.

Because of the larger diameter of the bearing surface the spring will
now ride in a different spot in the groove. Because the Teflon tubing is
quite smooth there will now be very little friction and the movement of
the spring will be much smoother. I’ve done this little operation to a
number of pianos in which regulating stability was considered important,
such as pianos that are regularly used for concerts. It has always
worked extremely well for me. Once the springs are set, they pretty much
stay put.

Let me know if this doesn’t answer your questions. If you can’t
visualize the thing, send me a spring and I’ll fix one up for you.

—ddf