Soundboard installation with hide glue

[Richard Brekne]

Hi Stéphane

I just ran into an argumentation I thought was kind of important, so 
I'll share it.  It goes to the claim that hide glues are necessary 
because of their ability to harden as they do and thereby transmit 
vibrational energy better.  The argument against this was real simple 
and made a lot of sense. It simply stated that the wave lengths of all 
relevant  frequencies are so long that the whole idea is moot to begin 
with.  As the reasoning goes... in order for this hardening to have any 
practical meaning at all we would have to be talking about very short 
wave lengths far out of the range the piano actually produces.  I 
haven't had any time to look into the matter so I have no idea really as 
to the truth of the matter.

The other thing discussed recently is that in the case of the 
soundboard... it is actually a "desirable" that the glue be able to 
creep slightly. Obviously in the case of a hitch pin rail that is glued 
into place on an historical instrument or a Cembalo this is not a good 
thing... but thats a completely different situation.

If these two reasonings are sound... I see no reason why something like 
Tite Bond can not be just as successfully used both physically and 
acoustically as hide glue.

Just a few thoughts for the day :)

Cheers
RicB


    I'm about to install my second new soundboard into my 23rd piano. 
    The first
    one I glued with fish glue.  This one, I want to try with hide glue,
    as I
    read somewhere that only this glue will and fill the small gaps
    efficiently,
    and dry very hard, favoring minimal energy loss at the joint.
    Do you think at some cave at's, or do you have special advice for this
    situation ?  I already understood that I need one or two helpers in
    order to
    spread the glue very quickly.
    I'm just asking now, because Friday it will be too late.
    A fellow restorer did tell me to bore the holes in the soundboard at the
    place for the plate bolts in two times, starting the hole from
    below, and
    finishing from above, in order to avoid those nasty wood splits when the
    bore come out.  I know this can sound pretty obvious for some, but I
    have to
    admit that I wouldn't have thought of it, and would have had to do
    the first
    bad experience before upgrading my process.
    I'm now in the mood of upgrading my process before doing some more bad
    experience.  You all know what I mean.

    Thanks in advance.

    Peace to all.

    Stéphane Collin.