Soundboard repair question

[Richard Brekne]

I dont think CA would do well for soundboard cracks.  Maybe if they were 
really thin hairlines... but I doubt it.  You can use an epoxy.  I have 
used West System epoxy in the past with great success for years and 
never had a sign of a soundboard re-cracking along the old crack lines.  
You tape the underside of the cracks so the epoxy doesnt just leak 
through. Use some good strong adhesive tape.  The epoxy does not need to 
behave like wood in the face of humidity changes. It just needs to hold 
on to the edges during tension periods and stand up under the pressure 
during compression periods.  The rest of the wood (probably 99.% percent 
of the total resultant panel) will take care of dealing with humidity 
changes.

By the sound of your question I'd like to add that this kind of job is 
done with the strings removed.... just in case there was any question.

If the pianos sound good, and the cracks are only thin more or less 
hairline in character... I wouldnt bother.  In fact I dont bother with 
filling cracks in soundboards anymore as a general rule.

Cheers
RicB


    This question was posed to me yesterday by the facility manager of a
    local
    community center:  could a cracked soundboard be repaired by dripping CA
    into the crack (as is done with bridges)?

    My questions were:  would CA hold up and would it help?

    I didn't know the answers to any of those, although I could hypothesize
    some.  BTW, I told him NOT to try it, since both the pianos with cracked
    soundboards are Steinways:  a 1950s B and a 1931 L that's been
    rebuilt and
    refinished.  And nobody ever mentioned (or remembered) to think about
    humidity control.  Harrumph!  The cracks aren't horrid, but they are
    there.

    Thanks for any comments.

    Annie G.


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