Carol, I'm sure other techs will confirm, but if you every get into a piano that has been exposed like this one, the stock response is either total rebuild or replace AND only rebuild after the piano has set for a year or two to see if the case is going to hold together. Ken Gerler ----- Original Message ----- From: Carol R. Beigel <crbrpt@bellatlantic.net> To: <pianotech@ptg.org> Sent: Thursday, May 25, 2000 10:15 PM Subject: what is this corrosion? > Hope some of you might know what is going on with this piano. It is about a > 14 yr old Kawai GS-30 and four years ago, the household sprinkler system > went off overhead while the owner was at work. The piano was completely > closed (lid and fallboard down) and water was sprayed on the high polish > finish of this piano for an undetermined amount of time. The immediate > observation was that water had not directly poured into the action or > pinblock area, but the action was damp and the keys were stuck. > > The first piano tech on the scene pronounced it a write-off. Actually, I > would too using my formula water + wood + piano + plus insurance premiums = > insurance company replaces the piano. However, for some reason, a second > technician was called out about a week or so later. The piano had dried out > a bit by then, and he didn't feel that there was sufficient damage to the > instrument to rate an ethical pronouncement of piano replacement. The piano > owner > had bought the instrument used. > > Anyway, a decision was made to replace the strings and tuning pins that had > rusted from this accident - perhaps a dozen. The insurance company settled > the claim and covered all the repairs that Tech 2 thought necessary. > By the end of the repair work, several months later, no rust was apparent. > > Now, four years later, corrosion is rampant, but in an odd way. The new > strings and pins are fine. The speaking lengths of all the strings are fine. > Only on some sections where the strings cross the understring felt is > there rust. All the coils are rusted, but it almost looks to me like the > plating on the old tuning pins is rusting, not the coils themselves. There > is also rust on the INSIDE of the brass agraffe holes and at the bases of > the agraffes. > > My guess is that the rust is appearing on the metal underneath the various > platings where the plating has worn off - like the edges of the tuning pins > that contact the tuning hammer tip; where string coils friction may have > scratched the plating on the tuning pins, and on the agraffes where the > strings passing thru the holes have worn the brass plating thin. Perhaps > the rust appearing at the base of the agraffes is where the threads > underneath the agraffes are not solid brass, but plated steel. > > Would a reasonable repair be to clean off the rust, and spray lacquer on the > tuning pins and coils and agraffes? Would that hurt anything? > > Could there have been something corrosive that eats plating sitting in the > sprinkler pipes? I think residential fire sprinkler systems use PVC pipe, > not galvanized steel ones. > > The insurance company says they settled the claim years ago and they are not > interested in funding anymore repairs. I have been asked to give a second > opinion in this case, but I have never seen anything like it. How about you > guys? > > Carol Beigel > > >
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