Decomposing key leads

[Jessica Masse]

Hi,
I once had a customer with an inexpensive probably Chinese made grand 3 
years after it was built the keys were binding.  I could not reach the 
manufacturer of it but contacted a technician  the US plant that 
probably contracted its construction.  This swelling key led problem can 
be seen rarely and I have seen it in older pianos.  Because the 
oxidation is a yellowish powder I wonder if it is zinc?

Anyway  this 3 year old piano probably built in 1997 keys were binding 
all over it didn't seem to affect the dampers.  The top surface of the 
keys had been finished I don't think this is relevant.  I took each key 
and with a sharp chisel or safety razor sliced off the protruding lead.  
Wear gloves don't make dust and store the leads.  Then I shellacked the 
surface of the lead.
This was done in 2000.  I saw the piano last about a year ago and 
everything is still okay.  I was unsure how long things would be okay.

Jessica Masse RPT