On 1/30/2011 12:59 PM, Chuck Behm wrote: > Here's my question. With the past rebuilds, I've decided that the gluing > method that I used to attach the bellows to the decks has not proved as > tight as I would like. I used hot animal hide glue, and clamped the > bellows with Jiffy clamps overnight. But now, 20 or 30 years later, I > don't think the seals are completely tight. Them's pneumatics, incidentally, specifically striker pneumatics. Hot hide is the way to go, as it's most effective and least destructive in the long run. If your shop is anywhere above 60° (65°+ is better), you don't need to preheat. What you do need is a proper gram strength glue, mixed to a usable consistency, a means of clamping the pneumatic to the deck immediately and firmly, and moving quickly enough that the glue doesn't gel. A gram strength of no more than 192 is recommended. That will give you good adhesion and working time. It's also the preferred glue for key bushings, dampers, and general felt work. I hang hammers with it too, or Pianotek's glue. Pianotek's 251 gram glue is good too, though not as friendly for general purpose work, and I don't recommend it for player work. It's better for hammers than the 192, as it stays put better and gels quicker. Schaff's 370-399 gram weight glue is well out of the range of anything I have a use for. I find it impossible to use. Aeolian used to bed a layer of what looks like cheesecloth between the pneumatic and the deck, though I typically don't replace it. If something's leaking in the player after 20 years, I'd bet it's not the pneumatic bedding joint. Did you do the valves, pouches, and all gaskets the first round? Ron N
This PTG archive page provided courtesy of Moy Piano Service, LLC