I read the question asking about the advisability of using white glue
on player actions.  The facts have been brought out many times on this
site, so maybe an example will help.

I recently tore down an Autopiano roll motor what I had rebuilt
carefully as a teenager forty years ago with white glue.  The
pneumatics were welded to the frame wood and they splintered apart into
many pieces when removed.  Some pneumatic wood stayed in rocky lumps on
the frame, some of the frame wood was pulled apart and stayed on the
pneumatics.

When I removed the cloth, some wood pulled off the side with the cloth,
some white glue stayed on the wood leaving lumps and uneven areas that
would have to be taken off with a sharp knife, leaving dips and areas
providing for poor sealing, if they would ever be recovered.

After dismantling, I was left with a heap of unrepairable kindling,
and I threw it all away and bought another Autopiano bellows engine
off eBay for ten dollars.  This I completely popped apart and stripped
in fifteen minutes with a putty knife and X-Acto knife.  As for the
pneumatic stack, it was useless as the same thing happened, only more
severely considering the fragile nature of striker pneumatics.  Other
bad things happen when using white glue, but I think the examples here
demonstrate something.

As for a hot glue pot skimming over, you might try turning down the
heat just a tad, or keeping it properly replenished with water.  I use
the same jar of hot glue for a year or two at a time, heating it and
stirring it and adding water as needed.  The expense of hot glue is
miniscule, its management elementary, and its "unknown qualities"
minimal.

A cheap and effective way for the hobby rebuilder to use hot glue is to
get an old percolator coffee pot, fill it half full with water and plug
it in.  Take a glass jar a little smaller than the top opening of the
pot and drop in a couple inches of hot glue crystals and add water a
quarter inch over that.  Drop it into the percolator.  Twenty minutes
later stir the mixture up, and you're ready to glue a stack.  When
you're finished, unplug and put a lid on the pot.  A month later when
you want to glue something else, plug it in, add a few tablespoons of
water to the jar, and glue away.

Tim Gautreaux