[pianotech] Expanding leads

[tnrwim at aol.com]

David

Good to meet you at the Westpac. It's always good to put a face with a name

In the 28 years when I was in St. Louis and Alabama, I ran across one piano with expanding leads. Now that I am here in Hawaii, I have had at least 40 pianos with expanding leads. So I am presuming that a lot of humidity has something to do with it. But I have talked with the other techs here, and none of us seem to know exactly why it is happening, especially since all the leads don't all corrode on the same piano. I've had Sohmers, Yamahas, Kimballs, Baldwins, and even a few Steinways with this problem. But, again, there might be 40 - 50 keys in one set that are expanding, but not all of them. So it's not necessarily the compound of the lead, since it is presumed that the leads used in one piano all came out of the same batch.  

 When I first got here, I was advised to chisel the leads down to the sides of the key, and spraying them with Shellac. But after a few years, those leads expanded again. So now I give the customer the option of replacing the leads or drilling them down. So far none of my customers have opted for the replacement process, mainly because the pianos do not justify the cost involved. What I am doing now is using a forstner bit to drill the leads down below the surface of the key about 1/16" and then spraying the lead with Shellac. The cost of doing that is about half of a new set. I know this is not a permanent solution, and it does change the touch weight on the keys a little, but as I tell the customer it will be 15 - 20 years before the leads expand to where they touch each other again, and by that time, it's not my problem any more. And most customers agree that it won't be their problem, either.  

But on your Bosey, the cost of replacing, and weighing, is definitely worth it. 

Wim


-----Original Message-----
From: David Love <davidlovepianos at comcast.net>
To: pianotech <pianotech at googlegroups.com>
Cc: pianotech <pianotech at ptg.org>
Sent: Tue, Mar 12, 2013 10:27 am
Subject: [pianotech] Expanding leads


While I have run into expanding lead problems periodically generally they seem 
to have been reserved for "lesser" pianos.  Today I found a 1950's Boesendorfer 
200 with leads expanding both in the back action and the keys to the extent that 
they were binding on their neighbors and on the verge of splitting things.  Of 
course I will have to remove and replace, a large task considering the new 
weigh-off at the key end that will be required.

My question is what is it that causes that reaction and why after such a time 
does it happen.  This is some 60 years later. 


David Love
www.davidlovepianos.com



 
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