Bridgetop Extravaganza Revisited

Farrell mfarrel2@tampabay.rr.com
Fri, 20 Dec 2002 08:14:53 -0500


Stephen wrote:

"The piano is long overdue for restringing.  It has never been restrung.  It is starting to shed treble strings.  Capo needs to be reshaped.  No one noticed the cap.  It does not sound good in the treble.  I thought I was catching a whiff of that old " If it doesn't have X amount of crown it isn't worth working on".  That was why I said I was not going to condemn the piano."

If the board is shot, not too many folks would condemn a 15-year-old S&S D. It may simply mean that it is time for a new board. With all the inequalities in bridge heights, and resultant funky downbearings, and apparently soft cap, it seems to me there is no good course of action short of recap if the board is "good", and recap and replace board if board is not "good".

It may take some explaining, but how are you going to explain it when chunks of epoxy start crumbling off the repaired bridge, etc., etc.? Explain to the "powers that be" that there is so much more that can be diagnosed when you start removing the strings - that is why you now can plainly see that recapping is a must, and maybe a board.

If the owners of a 15-year-old Steinway realize that it is "long overdue for restringing", then surely the "powers that be" are aware that a performance piano that sees a lot of use needs major overhauls every 10 to 15 years. Well, now's the time for an overhaul. Making bridge caps and perhaps a board of poor durability characteristics is NOT YOUR FAULT!

Just a few thoughts.

Terry Farrell
  
----- Original Message ----- 
From: "Stephen Bellieu" <sbellieu@mindspring.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: Friday, December 20, 2002 1:37 AM
Subject: Re: Bridgetop Extravaganza Revisited


Dale Erwin wrote:
Could you share how it is you're measuring 1.5 degrees of bearing on the bass and with what. If the rear string length was 8 inches( possible on a D) 8 Times .026=.208 or (1.5 degrees) of distance bearing . Considering this bass bridge has no cantilever  I don't mind seeing this at the top end of the bridge but I'd like to see .05 degrres in the mono section........................

Dale,  All measurements referred to so far were from the strung piano.  Individual strings were removed and thread/gap measurements were taken.  I was conservative in the bass and subtracted for the twisted part of the string riding on the hump.  Note # 3 showed 1.3 deg, note # 10 showed 1.7 deg, and note # 19 showed 1.3 deg.  Inverse tangent of (gap/rear length).
Did you mean to write .5 deg in stead of .05 ?   Just for giggles I checked one of the previously measured tenor bridge strings in the middle of the overstrung section after the bass strings were off.  (The following day)  It came up from .06 deg to .5 deg.


Greg Newell wrote:
I re-read your original post below and I still come to the same conclusion. It sounds as though you're somewhat accomplished in rebuilding so I'm not sure I understand your hesitation in recapping. If the original pins are loose and you don't intend to replace with oversize but you are going through the trouble of pulling the plate and then subsequent re-stringing then .... why not? ..............................

If I could do something with epoxy in a few hours and save all that expense. It will get new pins.  I am not an accomplished rebuilder or expert woodworker.  I have done dozens of restringings and several board shimming internal restorations with doweled in new blocks.  I haven't done any in shop belly work for almost a year.  Am doing mostly actions now.  At one time I was hot to try bridge capping but I don't think this is the right time for me.  The piano will go to another shop if that is the decision.  It has been a lot of dues paid to get to where I am right now.  It has kind of been a relief that the constant acquisition of tools has slowed and I have been busy doing things I am good at.  I'm reluctant to take on the big learning curve again.  It is tempting though.  I am handy with chisels and planes and japanese saws and reach for them first before power tools.  I used to cut down key # 88 with a bandsaw, now I pare it with a chisel just for the pleasure of it.

Ron Nossaman wrote:
But it's not being condemned, it's being restrung even though it sounded ok 
before? Is the damaged cap the reason for the restringing? And if so, why 
the reluctance to replace it? If not, why is it being restrung?

The piano is long overdue for restringing.  It has never been restrung.  It is starting to shed treble strings.  Capo needs to be reshaped.  No one noticed the cap.  It does not sound good in the treble.  I thought I was catching a whiff of that old " If it doesn't have X amount of crown it isn't worth working on".  That was why I said I was not going to condemn the piano.  I was trying to find out if any one had done the kind of bridge top resurfacing that I am imagining.   I have an obligation to try to repair economically before replacement.  

>I'm anticipating tight new bridge pins are going to contribute to tonal 
>improvement up higher.

Why, considering the condition of the cap and resulting bearing measurements?

The pins come out easily.  I thought the bearing was ok in that part of the piano.  (I'm not an expert,  I'm soliciting an opinion from you rebuilder types) 


Everybody,
     One thing I have learned already is to inspect every piano in the field if possible.  I hate these kind of surprises.  Forgive my lack of protocol knowledge on this kind of message board if I'm creating strange posts.  I guess we have to be careful not to take each other out of context with all this cutting and pasting.
       I attempted to quantify the condition of the grooves now that the strings are off.  Either it doesn't look as bad as I thought or I'm getting used to it.  Maybe they are swelling up a bit.  Humidity is up.  I held a straight edge on the edge of the bridge and slid a needle under until it stopped.  It measured between .025" and .030" in tenor and low capo.  High capo was .020" to .025".  Actually that is about as bad as I imagined,  the strings were about 2/3 into the top.  I have no idea what "normal" wear is because I have never thought about this before.  Mitigating factor :  the wood at the edge that the ruler was on is a little bit puffy.
     Is this too far to sand/plane down?   Could the duplexes be ground down a bit if so?   This might be my last gasp here.  Does anyone know of anyone who has attempted to resurface a top?  I guess this is mostly for my own interest since I would only do it if it were a known procedure that worked.  Like epoxying pins is now a known procedure.  I seem to remember it used to be controversial.
     I just had another thought that might not offend those who thought any buildup of epoxy in the groove would fail.  What about swelling the top a little,  then planing,  then renotching,  then pins in w/ epoxy and saturating notches and top.  Any amount the grooves swelled up would then be saturated and not built up.  (Wood Epoxy Saturation Technique anyone?)

Cheers,  Steve Bellieu


  ----- Original Message ----- 
  From: Erwinspiano@aol.com 
  To: pianotech@ptg.org 
  Sent: Wednesday, December 18, 2002 6:04 PM
  Subject: Re: Bridgetop Extravaganza Revisited


  In a message dated 12/18/2002 4:03:28 PM Pacific Standard Time, sbellieu@mindspring.com writes:


    Subj: Re: Bridgetop Extravaganza Revisited 
    Date: 12/18/2002 4:03:28 PM Pacific Standard Time
    From: sbellieu@mindspring.com
    Reply-to: pianotech@ptg.org
    To: pianotech@ptg.org
    Sent from the Internet 

         Steve


          Could you share how it is you're measuring 1.5 degrees of bearing on the bass and with what. If the rear string length was 8 inches( possible on a D) 8 Times .026=.208 or (1.5 degrees) of distance bearing . Considering this bass bridge has no cantilever  I don't mind seeing this at the top end of the bridge but I'd like to see .05 degrres in the mono section. That being said I've seen D basses set up with more than that that sounded great and ones with nominal bearing or none that sounded somewhat  weak. Where's the beef?
    What's really there has or will come to light with the strings off no doubt.
         Dale Erwin








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