One of our esteemed colleagues does not directly participate on these lists (or any other lists for that matter), but benefits indirectly by having me consult all y'all on his behalf from time to time. Below is his description of the problem he is currently facing.
"A 1988 American Steinway B has stuck hammer flange centers and the flanges themselves are stuck, almost glued, to the black cloth on the hammer rail. The hammer rail cloth was definitely gooey. When I began repining, both ends of the extracted center pin were coated with a black, sticky substance from the bushings. I repined a total of 9 hammer centers. Most would swing one time or were completely frozen, several swung three times. The rest of the hammer centers were free. The problem presented itself as no or slow repetition.
The owner of this piano has a humidity control system (just a humidistat and the heater rods, since it is never too dry in her home) and a string cover. The piano stays in tune beautifully.
This piano was made after Lloyd Meyer left Steinway when they briefly used the Renner parts on B's and D's and went back to the American parts after Lloyd was gone. I believe they soaked the bushing cloth in some sort of liquid Teflon. Not sure and have no idea of the procedure. Protek did nothing. I needed to physically ream and burnish the bushings and install a half size larger (21) pin. I'm sure there will be more stuck centers."
I have not encountered this before. Have any of you?
Sorry, Alan, I had forgotten that you were acting for someone else.Any sign of the goop on any of the other rails or centers?Any sign that something was spilled into the piano?Well, how could you know ...
It would help me, at least, to know whether these parts are NY factory (maple, round cross-section, smaller pianos), or Renner-built (octagonal, hornbeam, in B's and D's). The Renner-built bushings at that time, if I remember correctly, were often lubricated with graphite. White cloth, black ring against the pin. These would sometimes get tight and slow in the way of a number of manufacturer's parts in the last few decades, seizing up during heavy playing. There has been much speculation on the cause, but the short of it is that those parts would misbehave, for me anyway, until repinned. I've tried a number of short-cuts, and they have not worked. This would match your description except for the gooey bit. Is this beyond what too much graphite would yield?BTW, it is entirely possible for only a few parts to have the problem. It is, unfortunately, also possible for the entire set to need attention.If, OTOH, these are NY parts, something was almost surely introduced after manufacture. The centers were sometimes spongy, but I've never seen any that showed any stickiness. In fact, as has been mentioned, there was sometimes too little adhesive, resulting in a tendency for the cloth to push out while repinning. I have, occasionally, had the NY bushings get stiff, again under heavy playing, but the cloth in these bushings always felt somewhat hard and a bit too white. As if the dipping compound was too concentrated. But certainly not black and certainly not sticky.The black action flange rail cloth was (and still is) self-adhesive. I have removed it from a number of rails, for replacement along with new hammers and shanks, and had to work on it a bit, scraping off the dried-out adhesive. But I've never had any that was stickier than the original adhesive. Your description would have me thinking, as others have said, of some contaminant that gummed up the adhesive. A petroleum-based lubricant would fit the bill nicely.If the bushing cloth is contaminated with a gummy substance, one should be able to feel that with a replacement pin before reassembling parts. That would concern me, as the problem might well recur even after repinning unless the parts were rebushed or (better) replaced.Doug