[pianotech] Player piano question

[Chuck Behm]

John - Thanks, I'll try your method. I would imagine that you need to be
very cautious heating the bottom of the bellows not to harm the bellows
cloth. Chuck


>I use hide glue.
I dampen and heat both surfaces.
By dampening the wood, you don't have some of the moisture 'sucked' out of
the glue.
The heating of the wood with a  heat gun also seems to help.
The consistency of the glue also has an effect, too thin is not good, as is
too thick.
Experimenting should help you figure it out.
I have never considered any other method of attaching the bellows
assemblies.
John Ross
Windsor, Nova Scotia.<
On 2011-01-30, at 2:59 PM, Chuck Behm wrote:

> List - I've got a question concerning a player piano rebuild that I'm
hoping those with more experience can give an opinion on.
>
> Back in the 70's and early 80's I rebuilt a number of player actions, but
I've since tried to steer clear, and leave the work to others with more
expertise than myself.  Recently, however, after some arm twisting, I
consented to take a player into the shop. The piano work is done, and I now
need to tackle the player action.
>
> Here's my question. With the past rebuilds, I've decided that the gluing
method that I used to attach the bellows to the decks has not proved as
tight as I would like.  I used hot animal hide glue, and clamped the bellows
with Jiffy clamps overnight. But now, 20 or 30 years later, I don't think
the seals are completely tight.
>
> Would I see an improvement if I were to preheat one or the other of the
wood surfaces? I've always wondered if the glue might have gelled
prematurely upon contacting the cold wood? Or, would I be better off to put
in an automotive type gasket material, and use Titebond? I want a bond that
is able to be torn back apart down the road, if another rebuilder does the
whole thing over again in some distant year. Not likely, I realize, but I
myself re-redid a couple of rebuilds where the previous rebuilder had glued
the bellows directly to the decks with woodworking glue. On one such pianos
I had to remake the entire set of bellows from scratch - a job that
definitely wasn't figured into the estimate!
>
> Duaine, would you have an opinion on this? What is the method you prefer?
>
> Thanks, Chuck
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