[pianotech] Restoring Crown to Undamaged Soundboard

[David Love]

For all the trouble it seems like putting a new board in isn't that much
more work.  If you wanted to take short cuts (budget and/or time
considerations) you could even just transfer the old bridge over adjusting
the height from the bottom (of the bridge) if you needed to cut corners.
Use a panel such as NW specialty woods is providing for $200 (non matching
grain a few knots and blemishes) and move ahead.  The hassle and risk of it
trying to restore crown by reribbing an original board in the piano hardly
make it seem worth the trouble.  

David Love
www.davidlovepianos.com

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Monday, July 06, 2009 9:43 AM
To: Roy; pianotech at ptg.org
Subject: Re: [pianotech] Restoring Crown to Undamaged Soundboard

Roy wrote:
> A few years ago, Ron Overs posted pictures of a procedure
> to laminate the ribs from the bottom.  It basically
> involved planing down the ribs, and then gluing on a layer
> of wood.   I forget whether the strips he glued on were
> crowned, or if he forced crown into the board. Maybe he can
> explain.  But the basic idea was to laminate crown into the
> rib.  This seems to me like the only realistic route to be
> able to re-crown an old board....by converting it from
> compression crowned to rib crowned. It seems like the hard
> part would be to get the ribs sanded flat enough to be able
> to get a good glue joint, because the beams are in the way.
> I haven't tried it, so I can't say how effective it would
> be.  It's one of those things that I've had in the back of
> my mind to try when the right situation comes along.
> 
> Roy Peters

As I recall, Ron's conclusion was that it seemed to work well 
enough, but wasn't realistically worth the time and 
aggravation. I've thought for a long time, and it's been 
mentioned to me by a few others as well, that the best chance 
would be crowned rib side laminations, likely of about 3mm 
maple, jacked up against the panel and glued to the rib sides. 
With the tooling and techniques to develop, the lack of room 
to work, and inaccessibility of the high treble in any case, 
it still seems like an expensive and probably ugly kludge.

It's been wished for many times through a lot of years, but to 
my knowledge no one's come up with a practical method that 
actually works.
Ron N