[pianotech] re-fabricating a failed soundboard

[Ron Nossaman]

On 5/27/2012 9:29 AM, jim at grandpianosolutions.com wrote:

> The board is steamed out from above, steam penetrating the soundboard
>  from above and making its way through the wood to the glue at the
> rim, case veneer protected from the steam. The board is extracted
> whole, with none of the pulling of spruce grain that often
> occurs(even with masking tape..geez). The ribs are steamed off whole,
> again no damage. Board is re-glued as necessary and an occasional
> small 1/8 or less piece of old spruce glued in mid panel at
> appropriate places, to make up for what cross grain dimension has
> been lost to compression (although they say compression set is
> BS...we'll skip that, little side show) but in any case returning the
> panel width to its original width.
>
> Panel dried as in compression crowning, original ribs glued back on
> to original panel, at original grain angle in a dished deck (I
> think). Old wood configured to original width takes on a healthy
> crown, and healthy to significant downbearing.

There was a fair amount of discussion on this LONG ago (like 1998), that 
re-using panels was common practice in other parts of the world. They 
replaced the ribs, though I'm not sure why, and compression crowned the 
reassembly.


> My hunch has been that the old soundboard wood, if it could be
> reclaimed with enough left to reuse in a panel, could be, if
> structure was re-built into it again, as in a new ribbed fabrication,
> could be a viable soundboard structure.

That's been acknowledged a lot of times here. The part of the question 
that's left out is what type of construction is being used. Countless 
compression crowned boards failed since being built. If these boards 
being discussed required re-ribbing and insertion of strips of old 
spruce to compensate for the compression set that didn't happen  and 
take them back to full width from which they mysteriously presumably 
shrunk somehow, they were apparently among the failed. Reproducing the 
conditions under which the original failed with the original material 
seems to me to be rather optimistic and not really paying attention.


> I think they are earning at least $3 an hour on these babies( on a
> good day)...anyone want to line up for a franchise<G>

And, there is that. More time spent ought to be offset by performance of 
some definable sort, shouldn't it? Where's the trade off?

More and more, we're hearing about ways of trying to save the old dead 
materials most of us gave up on long ago and replaced with new. I fully 
expect at any time to read of miraculous results obtained from soaking 
old pianos in vats of Ressurectum to eliminate all parts replacement, 
refinishing, regulation, voicing, and any further need for tuning - 
either aurally or with an ETD. Sooper Goop!

Any day now.
Ron N