[ Tom Sendall wrote in 100502 MMDigest:

> Before I tear off all that good-looking cloth and recover the bellows,
> I was wondering whether there is a flexible sealer I could coat the
> exterior of the cloth with to decrease its porosity, and save myself
> a big job.  Or is this just wishful thinking?

Tom,  Boy, have I got a deal for you!  Get yourself a bottle of
Pliobond and a can of acetone.  Pliobond is basically rubber dissolved
in acetone with the addition of some additives and an UV inhibitor.
Mix it about 50/50.

You may want to experiment a bit to get the best ratio.  You want it
rather thin.  Put on a coat of Pliobond and see what happens.  You may
want a second coat.  But, like paint, a thick coat isn't good.  You
don't want to see the build-up.

I restored a Wurlitzer harp over 10 years ago.  The pneumatics were a
mess after 100 years -- you could see right through the cloth in places,
and the rubber was 'crispy'.  But the mounting board was fragile and
I didn't want to take all 60 pneumatics off to recover them.  Some of
them leaked a couple hundred cubic inches a minute.

After one or two coats of Pliobond, none of them leaks more than about
five cubic inches per minute.  That's on a par with the air leaking
through the wood.

Make sure that you don't let the surfaces of the bellows touch each
other until it's completely dry -- when the smell is gone.  And, for
good measure, I also dust the surface with talcum powder after I think
it is dry.

Good luck.
Craig Smith - near Rochester, New York