[pianotech] Damper spring

[Richard Ucci]

JD,
I still see alot with just cord and no pin.
Also the pace book doesn't mention pinning the spring.
Do all pianos need both?

Rick Ucci/ Ucci Piano
www.uccipiano.com


On Jun 19, 2011, at 10:05 AM, John Delacour <JD at Pianomaker.co.uk> wrote:

> At 09:05 -0400 19/06/2011, Richard Ucci wrote:
>
>> Last week I was working on an old Chickering upright and wanted to  
>> replace a bass damper spring.
>> It was pinned and after removing the pin it still was connected.  
>> Seems to also have cord in there as well.
>> Why both? When redoing does it need to be same again?
>
> The most common thing found is a pin with bushing cloth or thin  
> facing cloth, not cord.  The pin is there because without it the  
> pressure of the coil of the springs would push out the cloth.  The  
> cloth is there to prevent wear and squeaking and the pin is there  
> for stability.  If you use just cord you will probably find that it  
> pulls up.  The pin and cloth allow for free movement of the coils.   
> If you use something that is a tight fit in the coils, the coils  
> will be unable to do their job of closing up as the spring tightens  
> and the life of the spring will be greatly reduced through fatigue.
>
> Tear of some strips of cloth as though you were going to rebush  
> centres, but the cloth can be thinner since it only needs to be  
> tight enough to keep the pin in place, so it is an easier task than  
> rebushing centres.
>
> JD