Mysterious blocking notes

[Daniel Honnold]

Aaron Bousel wrote:
>
> List,
> I've sent this twice in the past two days.  Hoping it will go through now.
>
> I have a customer with a S&S 'M' with an elusive, mysterious action problem.
> First some background:  It is serial number 490934 built in 1984.  The
> action is cloth bushed, except for a Teflon plug that holds the repetition
> spring in place.  It has those screws with the reduced and knurled bodies
> (just below the head) that sometimes break.  (This is irrelevant to the
> problem, but might help someone identify the action.)
>
> The complaint is that, on occasion, apparently at random, certain keys won't
> go down.  Or more precisely, they will go down but require an additional
> amount of force to start them.  Typically, he will be playing a passage and
> the note or notes resist his touch.  If he stops and goes back to those
> notes, they seem to work fine.  Needless to say, the piano smelled me coming
> and played fine when I tried to duplicate his experience.
>
> As he found the problem to be worst on notes C-52 and D-54, I began my
> investigation there.  The only thing I noticed that was different about the
> action parts in that area was that the wippens seemed too far forward, i.e.
> the capstan had worn the wippen cloth very near the back of its length, and
> the jack tail was hitting the let-off button very near the front.  I checked
> all pinning, lubed jack tops, and generally went over these two notes with a
> fine tooth comb.  I used travel paper on the wippen flange in order to move
> the whole wippen back just a bit.  Put it back in, and of course it worked
> fine.  But, it worked fine for me before, so I had no confidence that
> anything I'd done was of any use.  Tuned the piano and while checking it out
> after the tuning, I THOUGHT I felt a bit of resistance on G-47.  Going back
> to the note, I couldn't reproduce the sensation.  At this point I had to
> leave so I explained that I'd tried some adjustments and as I was coming
> back in two weeks to tune his upright, I could look into again at that point.
>
> Two weeks later he said it seemed much better, but G-47 stuck on him--once.
> G-47 didn't exhibit the same alignment problems I saw at the end of that
> section with C52 and D54.  I did everything to G-47 I had done to the other
> two notes, except shimming out the wippen flange.
>
> That was a month ago.  I just got off the phone with this customer and he
> said that just last Saturday A-49  'blocked' on him.  He went to the
> Steinway dealer here, who has sold him a Dampp-chaser (which I've been
> trying to do for awhile now) but I doubt that this is a humidity problem.
> For the moment he's going to let the Dampp-chaser work for awhile and see
> what happens.
>
> The sensation I felt was as if someone had pushed a tri-chord damper just a
> bit down into the string and then tried to play the note, an initial
> resistance, then it lets go.  I don't think that it has anything to do with
> the dampers, that's just a good description of what it feels like.  You may
> have noticed, as I did that it only seems to happen on the naturals.  I
> checked out the keyboard and everything looks fine, keys moving as they
> should, not chucking.
>
> Has anyone ever come across this before?  I would sure be great to be able
> to come back to this guy with something concrete.  Thanking you all in advance.
>
> Regards,
>
> Aaron Bousel
> Ormstown, QC  Canada
> abousel@rocler.qc.ca
perhaps the capstains need polishing and the whippen pads need replaced
or lubed. teflon powder.