what is this corrosion?

[bases-loaded@juno.com]

I have done 4 "fire" jobs, each time waiting 6 months before making a
final estimate/appraisal.  Each time a complete restring job was done, as
corrosion continued to show progress over the waiting period.  All of
those jobs have turned out well, even 10 years later.

Interestingly, one set of bass strings was COMPLETELY dead on a Kawai
grand on initial inspection, and 6 months later sounded just as good as
new.  I replaced them anyway, but found that to be rather intriguing....

AS far as spraying lacquer on pins and coils, that doesn't sound like a
very good idea to me, although it may be OK.  I would think applying some
bluing fluid after cleaning off the rust would be preferable, and more
effective.  At this point, only band-aid approaches or a restringing
would seem to be the choices.  Tech #2 did this customer a great
disservice.

Mark Potter
bases-loaded@juno.com

On Fri, 26 May 2000 00:11:19 -0500 "PAT A RALPH"
<KENNETH.GERLER@prodigy.net> writes:
> 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
> >
> >
> >
>