"I have tried just about all the suggested methods of cleaning real ivories but none of these gets the dirt out of the "ivoryite" that Yamaha uses on some of their grands. This is quite porous material and the dirt penetrates beyond the action of any cleaner I've used. Any suggestions." The Ivorite on Yamaha pianos prior to serial numbers in the 4,750,000 range had a formula that allowed the stain from the sharps to penetrate resulting in staining of the naturals that no cleaner can remove (this has since been corrected). The only remedy is a full keyboard replacement (including sharps) which Yamaha has always been willing to provide (labor included). Call Greg Frank at Yamaha 800 854-1569 to discuss the procedure. They have always been concerned that all pianos with this problem be attended to and at times have covered the claim even if it isn't the original owner since any pianos out there with this problem reflect badly on Yamaha. If I'm not mistaken, there once was a question posted here on the time approximation for installation that should be in the archives. Larry Newhouse San Francisco Conservatory of Music
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