[pianotech] Soundboard repair

[Dale Erwin]

Hi Roger, all.
 Thanks for psoting this.
 With all sincerity and without stepping on your comfort zone Roger, I'd like to offer another experience. My comments interspersed below

Dale Erwin R.P.T.


Roger wrote



Chuck,
I’m stepping out of my comfort zone to respond to your post – a post that may mislead new technicians who may be inclined to venture down the paths of restoring 100 year old pianos. By simply filling the cracks with shims and performing a static gluing of the panels to the ribs, your chances of restoring a 100 year old soundboard to it’s original impedance character are little to none.Your comment about a 1000% more “vibrant” is misleading.


Certainly results can vary, and you have a valid concern to be certain sure but I've restored several hundred uprights in 40 years. Some were fantastic doing only what Chuck suggests and others only fair. I really think that upright boards are more driven by the mass and stiffness of the materials alone unaided by any notion of much if any mass and stiffness provided by crown and downbearing. 


  The stopgap repair certainly restored unity to the soundboard, but after that, a piano with that much deterioration would have little to no tension remaining within its composite structure. It defies the physics within the soundboard to believe that a massive gluing of that nature restores any rib-to-panel tension; tension that is necessary to the characteristics we associate with good piano tone.
 
I think I would substitute your word tension perhaps for integrity. A soundboard doesn't need tension as I understand it, it needs compression.  I've restored uprights , repairing a few cracks with no crown, regluing ribs to restore panel integrity etc. This done in conjunction with removing the old finish and applying an epoxy finish to the soundboard which has improved the sound dramatically. Of course new bridge caps/strings also helps enormously as does a modest amount of pressure against the them and the board. Everything can help if the design is adequate to begin with.


 
When I was young and felt I knew everything about the make-up of the piano I ventured into a massive static soundboard re-gluing job where every rib along 75% of its length was detached from the panels. The end result was a disaster. It was like listening to a ball peen hammer striking against a cast iron frying pan – all attack and no decay.
 
I think my procedure varied  in one important dynamic way from what you had attempted.
 I executed a similar procedure on old no named family upright baked in the hot summer sun in a mini warehouse here for 10 years. The board had 3 full length cracks. I was able to open the glue joints on all the ribs from case edge to case edge.
  After drying the board these cracks allowed the board to be expanded, pushed toward the front of the piano as wedges were driven between the back posts and the ribs while being reglued and screwed to the ribs. Shims applied and The piano regained more belly than many new boards. It sounds remarkable. I was frankly proud of the repair and the results.
Granted this was a one time triumph but the principles are the same. Some force crowning and panel drying and the ability to expand the panel.
 As a side note I have observed that the number of ribs on the old monsters seems to be a determining factor when listening to and liking the sound of any old upright. For me,10 ribs is not usually not enough support or mass to provide a tone I appreciate or want to rebuild. 11 is better and 12 is great. Taller ribs are always a better sounding board to my ear. Ribs less tall and wider are not generally a good result. Sustain is my number one predictor (is that a word) of soundboard health and rebuild viability.


 I would urge technicians to seriously weigh the restoration investment to the end result before engaging in such a massive reconditioning. A good new upright piano can be had for $6,000 to $7,000, and it would have a new bridge, a new pinblock with 2/0 tuning pins, and an entirely new action, plus much more. Is it worth our reputation to encourage our clients to invest in a 100 year old piano with that level of restoration liability?
 
This point is well taken Roger. Careful assessments need to be made and options considered.
 However uprights on the west coast have often survived in unbelievably good original conditions and are more than worthy of restoring with outcomes that in my opinion far surpass new pianos both in tone, touch and beauty. 
  These gorgeous Victorian cases will NEVER , NEVER be made again and many should be preserved even  though it can be expensive.
I've got some rebuilt uprights out that are tonally superior to anything new. IMHO.
Merry Christmas
Dale


Roger Gable

 

From: Chuck Behm 
Sent: Saturday, December 22, 2012 9:30 AM
To: pianotech at ptg.org 
Subject: [pianotech] Soundboard repair

 

Hello again - For those of you who entertain yourselves upon occasion with refurbishing and old upright with a loose and cracked soundboard, I've come up with a quick and easy method of regluing the ribs to the soundboard before shimming that really seems to do the trick. I don't believe I've ever seen it done this way before (that doesn't mean it hasn't been done before - I just haven't seen it done [or don't remember seeing it done, which at my age may be a more accurate way to put it]). 
 
Anyway, click here (I hope the link works) for a photo set that highlights the process. The soundboard of the piano in the photos is a 1000% more vibrant now than it was before the procedure was done.  Chuck


 

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