Why?

[Billbrpt@AOL.COM]

In a message dated 3/10/01 10:47:35 AM Central Standard Time, 
tito@PhilBondi.com (Phil Bondi) writes:

<< The note played just fine until the damper pedal was depressed.
 
 (snip)
 Is there something I missed in my trouble-shooting that will cause this
 problem to surface again?..and why would this note only stick when the
 damper pedal was depressed? >>

This is a very common complaint.  I saw this post well after you have already 
had good responses but I'd like to elaborate a bit.

There are at least 100 problems that a customer might identify as a "sticking 
key".  I remember a list from about 20 years ago entitled "101 Causes for 
Sticking Keys".  Just as with elusive noises in the piano, there may be more 
than one source for a "sticking key" problem.  It takes a good diagnostic 
prodedure to resolve the problem entirely.

You were correct to rule out a tight center in the wippen flange because 
there is no reason why you could not have *both* a tight center *and* a tight 
key bushing or keypin hole.  For that matter, they could *all* be tight or 
any combination may be.

Usually, however, the common complaint that the key sticks only when the 
damper pedal is depressed means that there is only *marginal* tightness in 
one of these places.  The damper lever spring is usually very strong so it 
serves to push back against the spoon much the way the repetition spring in a 
grand wippen pushes against the key, aiding return.  Pressing the pedal takes 
the spring out of the works.

Coincidentally, the last piano of the day for me yesterday had this very same 
problem.  I detected some sluggishness in a few keys when tuning and saw that 
with the damper pedal depressed, they stuck right down.  It was a Baldwin 
Console.  I removed the keystop rail and the music shelf supports so I could 
lift the fallboard to ease some keys.  (The fallboard itself is tricky and 
difficult to remove and replace on these, so if I don't really need to remove 
it, I don't.)

Even upon finishing the job, I depressed the damper pedal to play a big F 
Major arpeggio and F2 stuck right down even though I had no problem with it 
when tuning.  I decided this meant that I should check *all* keys with the 
pedal down just to make sure I wouldn't have a call back complaint about keys 
still sticking.

Whenever there is a general sticking key problem where you have determined 
that the friction is in the keys themselves, it is a good idea to remove the 
action (if it can be done easily) in a vertical or the action stack in a 
grand, lift out the keys, vacuum, then lube the keypins, bushings and keypin 
holes.  Protek works well for this but I usually use the "Wet Lube" from 
Schaff Piano Supply.  There are other good lubes but Silicone based lubes and 
WD-40 are *NOT* recommended.

After cleaning and lubing the keys and keyframe, you should find that the 
keys move much better with a minimum of easing required.  When easing, 
determine *first* which of the 3 points is sticking:  keypin hole, balance 
rail bushing or front rail bushing.  To do this, drop the key down on the 
balance rail pin.  If it is the keypin hole which is tight, it will not drop 
or will drag noticeably.  If it is the balance rail bushing, it will catch 
there.  Once these two points are shown to be free, then the front rail 
bushing will feel tight if the problem is there.  You would feel virtually no 
side play in such a circumstance.

This diagnostic procedure is important to avoid over easing of points which 
are not tight to begin with.  Go *easy* with the keypin hole easer and easing 
pliers.  These crush and deform the wood which weakens it.  They should be 
used with gentle pressure.  In some cases, it may be better to remove a 
little material rather than simply crunching the wood.  In the case of a 
tight front rail bushing, make sure the front rail pin has not been or become 
turned sideways.  If it is and it turns very easily, it may become turned 
again by itself over time and the same problem will recur.  A little water 
thin CA glue applied at the base (with the punchings removed) will tighten it 
up to where it can only be turned with substantial force.

I hope this clarified a few things.

Bill Bremmer RPT
Madison, Wisconsin