[pianotech] Totally glueless

Ron Nossaman rnossaman at cox.net
Thu Jan 31 07:36:23 MST 2013


On 1/31/2013 8:05 AM, Ed Foote wrote:

>   Ok,  a question, then.  Do you glue your bridges to the soundboard,
> and if so, why?

I sure do, because we all know that screws can become loose through time 
and humidity swings. My bridges will hopefully have positive bearing on 
them, so even with slightly loose screws and no glue, they still ought 
to work. Glue insures a solid mechanical connection for a long time.


> I don't think a pair of screws couples the bridge
> adequately to the soundboard, either mechanically or acoustically, but
> if there are reasons why that coupling isn't worth questions, I would
> love to hear them.

It's the presumption of "acoustic coupling" that is questionable here. 
Good mechanical coupling is necessary for one part to move the other to 
make the system work. What I tried, unsuccessfully again, to point out 
was the difference in scale between the mechanical action that is taking 
place and the imagined tiny vibrations within the various individual 
parts. The basic action is much coarser and simpler than is typically 
believed. Was the O rebuilt because the bass was dead? Were the bass 
strings replaced and the bass was still dead? If the screws were too 
loose to provide a decent mechanical connection, that should have been 
the case. What prompted the rebuild?
Ron N


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