[CAUT] Servicing guide rail bushings

Stan Kroeker smkroeker at shaw.ca
Sun Nov 22 09:07:26 MST 2009


Ok ... thanks to all for the helpful advice.  I have scheduled a  
service appointment during which I intend on starting with the  
simplest remedies before the more invasive ones.  Thanks, too, for  
jogging my memory on Steinway's spec. re: damper wires bearing lightly  
against the bushing.  That tidbit was buried deep in my memory  
bank ... polite way of admitting 'I forgot'.  I somehow still like the  
idea of minimal free play in these bushings but realistically, it  
shouldn't make a difference.

Apart from the symptoms I mentioned in my original post, another  
annoyance that comes and goes is the damper wires buzzing against the  
closely spaced low-bass bichords.  Is it possible that, with the wires  
regulated to bear against the bushing, they may not be centered  
between adjacent unisons ... and if so, would it be permissible to  
make a slight corrective bend just above the guide rail (but below the  
string plane).  Or would this simply be compounding the error?

Finally, I still find it challenging ... more so on some pianos than  
others ... to 'pinch' the lower end of damper felt wedges (bichord and  
trichord) to neatly slip between the strings of a unision.  Out of the  
package they generally seem to just sit on top of the strings without  
actually wedging down between them.  I do have damper felt pliers  
(purchased from Jürgen at Pianofortesupply.com) for teasing these felt  
wedges into more of a 'chisel' point.  On this particular Steinway B,  
the bass bichords are so thick and closely spaced that it seems no  
amount of squeezing the dampers helps them wedge decisively between  
the strings.  Any advice on this issue?

Stan

On 21-Nov-09, at 2:30 PM, Stan Kroeker wrote:

> Dear Colleagues,
>
> Am regretting not replacing damper guiderail bushings on a recent  
> Steinway (1976 B) parts retrofit.  The new damper action installed  
> smoothly and required only minimal re-bending of damper wires.   
> However, in spite of careful attention to proper alignment and  
> seating of bichord and trichord damper wedges, I can't seem to  
> eradicate an 'oink' together with longer-than-satisfactory 'ringing- 
> on' of most dampers in this part of the scale.
>
> There is actually quite a bit of free play in the guiderail  
> bushings ... you can see the damper head wobble when the key is  
> struck.  Am kicking myself for neglecting this important interface  
> but, short of rebushing the rails, has anyone had success with  
> moistening the bushings in hopes of swelling them back to acceptable  
> tolerance?  I sometimes do that with moderately compressed  
> keybushings ... would it work on these as well?  If so, would you  
> mind sharing the procedure?
>
> Thanks and best regards from the Canadian prairie!
>
> Stan Kroeker, RPT



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