Ken, I can't answer your questions about the formaldehyde glue. For a 1/4" separation the most important thing is to stabilize the separation so it doesn't get worse. With this crumbly glue you talk about, I would probably tell the client that doing the job right will be very expensive, and give a quote for replacing the pinblock. I would also say that I am relatively confident that the piano can be repaired for a lot less than that, but unfortunately I can't give a guarantee. If he's willing to take the risk, pull the crack together with clamps the best you can, fill it with epoxy, and bolt it together good. NOTE: Whenever I don't guarantee my work -- for example, a soda straw repair of a hammer shank for a client who won't pay the labor for a new shank on a wornout piano -- I inform the client orally and also put it in writing on the invoice. I have to cover my own backside. Regards, Clyde Kenneth Zahringer wrote: > I was recently called to check out a piano that another technician had > declared untuneable. Well, he was right. The pinblock had completely > separated from the back beam - end to end, top to bottom. I looked in > the gap and both surfaces were covered with what looked like a flocking > of glue. I scraped some of the glue from the underside of the block, in > back, and it crumbled in my fingers - full of air bubbles, I think. > Once it crumbled, though, the remaining granules were rock hard. The > manufacturer said at the time this piano was built they were using > formaldehyde glue in this joint. The warranty expired some years ago, > so it's up to the owner and me to fix it. I would like to do this > without disassembling it, replacing the block, and restringing it. It's > not that old and the pins are still fairly tight. > > My problem is that old glue. I know there is no way I could clean all, > or even most, of it out of a gap that's barely 1/4 inch wide. And the > granule are so hard I'm sure they would prevent the two surfaces from > being clamped together effectively. Does anyone know of a way to soften > or dissolve formaldehyde glue? Can it be "reactivated"? If it were > softened or partly liquefied, would it interfere chemically with other > glue, like Titebond? Based on what little I know about formaldehyde > glue, I'm not sure I want to use it in my shop. > > Ken Zahringer, RPT > Columbia, MO
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