Hello everyone!
I am no expert in piano engineering and tuning, I am a beginner, a hobby enthusiast, and I love to learn and try new and odd stuff :)
I am restoring a grand action and budget is an issue... Also, in Romania you cannot find piano supply stores, and most of the ones in Europe won't sell parts to non-professional piano technicians... I am barely starting this career now...
The knuckles are pretty bad worn (flattened with pretty visible jack indents). The leather seems to be in an acceptable shape... I cannot afford a knuckle replacement set, so I searched the net for various methods of repairing...
What I have come up, rather than bolstering with yarn is a simple method to restore the compressed fibers of the felt inside the leather.
I drilled a 10mm (diameter) hole in a piece of wood, then cut it in half to make a caul, or mold (i don't know exactly the english word..). I then heavily impregnated the knuckle with isopropyl alcohol (as it came from the store, not further diluted with water) and applied the caul with a clamp. After about 2 hours, when I removed the clamp, the knuckle was perfectly round with no jack marks and holding shape (it seemed to have the same stiffness everywhere).
I still have a lot of knuckles to reshape, so I haven't had the chance to test them yet... but I'll let you know. It seemed like an interesting experiment. And it might work, because, I think, the felt should be intact inside a worn knuckle, only compressed in a wrong way... don't you think?
I would be so curious what a professional would have to say about this experiment... :)
Cheers!!!!
Ovi
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Ovidiu Turcu
Piano Tuner and Technician
Bucharest
+40724414692
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