[pianotech] Fwd: Bummer Bass Bridge

Terry Farrell mfarrel2 at tampabay.rr.com
Sun Feb 20 07:29:49 MST 2011


No capping material at all. Solid maple (I think) bridge - top to  
bottom and everywhere in between.

If they are going to offer to replace the piano, I wonder whether she  
would be better off with another piano made of the same materials, or  
if she would be better off with this piano after repair and  
installation of a good laminated hard maple cap. I suspect the latter  
- especially looking far down the road of time. John Formosa's comment  
that he has seen the same thing on a new piano of the same model as  
this is especially concerning.

If I were to repair it, my main question would be with regard to the  
treble bridge. The bass bridge is a no-brainer - repair/replace the  
root and put a good laminated cap on it. But the long bridge is less  
clear. The cracks are big in the very low tenor and diminish to not  
visible about where the long bridge is half way across the bass string  
section. So one could argue that only the tenor section of the long  
bridge would need a new good cap (not that there was one originally).  
That would be something reasonable to expect from the dealer/ 
manufacturer standpoint. But from her standpoint, it would seem to me  
that a recommendation to cap the entire long bridge with a good  
laminated cap would be prudent - the thought being that as long as you  
are in there tearing the piano apart, might as well do what will be  
most productive to make and keep the treble clean and clear for many  
years to come.

Any thoughts on that?

Another question. I've repaired bass bridges and have always just  
loosened the tuning pin just enough to yank the string loop off the  
hitch pin and move the string out of the way. I have not ever repaired  
a long bridge where I wasn't restringing anyway. Regardless of whether  
half the long bridge is to be recapped (awkward term to use when the  
original did not have a cap) or the entire bridge is to be recapped -  
what works best - pop strings off loop and reuse or remove all strings  
and restring after bridge work is completed. Seems to me if you left  
strings on the tuning pins you'd really have yourself a big pile of  
spaghetti and end up putting kinks in wires, etc. - maybe better off  
to just restring. And if I did restring, remove tuning pins, or just   
loosen on turn and put the new strings on with a pre-made coil? Seems  
to me a lot easier to remove pins and install new ones, but then again  
that would unnecessarily enlarge the tuning pin hole in the pinblock -  
you'd probably want to got up one pin size - pretty cruddy thing to do  
on a new piano.

How can something so simple generate so many questions?

Terry Farrell


On Feb 20, 2011, at 8:18 AM, Ron Nossaman wrote:

> On 2/20/2011 5:16 AM, Terry Farrell wrote:
>> Hmmmmm, is this a test? That's funny - I can only picture you as the
>> teacher standing in front of the class asking that question - one  
>> that
>> you already know the answer to!
>
> Nope, it's just a long time cumulative observation.
>
>
>> So, okay, I'll bite:
>>
>> Interesting question. I would presume it would be most likely  
>> related to
>> the grain angle in the bass bridge - that a weaker orientation  
>> lines up
>> more favorably with the speaking pins and cracks more easily. But  
>> come
>> to think of it, when I have seen a cracked bass or high treble  
>> bridge,
>> it is almost always the speaking side that cracks more. Could it be  
>> that
>> the string doesn't tend to render through the bridge pins  
>> completely and
>> more tension is on the speaking side of the string and thus more
>> pressure is applied to the speaking bridge pins?
>
> I don't know. There are times in the humidity cycles where the  
> static tensions of the back scale will be higher than speaking  
> lengths, so I don't think that's it. Impact pulse, or factory  
> seating methods? I don't know, but I think I can accurately say it's  
> apparently not ideal capping material.
> Ron N



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