Many thanks to Ralph Nielsen for his most well-informed posting
yesterday.  Many of us have tried modern glues and found them wanting
in certain applications and I thank Ralph for detailing his experience
so eloquently.

I have used hot glue for over thirty years but also use PVA and PVC-E
glues in certain applications, predominantly on joints that need to be
permanent, such as structural joints.  I always use hot glue for action
work, such as when using rubber cloth, leather and felts etc.  I am
also a great fan of burnt shellac.

As a member of the British Player Piano Group I read Paddy Handscombe's
treatise on modern materials and glues and was interested in his
discussion on PVA and PVC-E glues.  As Paddy says, not everything that
looks like white glue is PVA.  Most (possibly all) PVA glues have the
designation PVA on the label.  So far, so good.

The most popular wood glue in Great Britain is Resin-W, made by
Evo-Stik which is now a division of Bostik.  Unfortunately, neither the
container nor an extensive trawl on the Internet will tell me what type
of glue this is.  The only specification I can find is that it complies
with EN 204 Type D4, which defines weatherproofness.  Paddy tells us
it is a PVC-E, which I will accept.  So now I can investigate the
comparative post hardened solubilities of these two types of glue.

I set up an experiment using sections of hardened PVA (a decorator's
glue from a well known do-it-yourself outlet) and PVC-E (Resin W
weatherproof) on a piece of wood.  These were not assembled joints,
only lengths of hardened glue.  I soaked each length of glue with
water.  After about 15 minutes the PVA came away and a few minutes
later so did the PVC-E.  Both lengths of glue remained intact and
appeared milky and slippery to the touch.  I believe the adhesive joint
was loosened by the water soaking into the glue/wood interface and
releasing the cohesion.  Both lengths of glue remained intact as
rubbery masses.  My conclusion is that there is no significant
difference between the water solubility properties of PVA and PVC-E.
Both will come away with extensive soaking and both are not truly water
soluble once cured.

The results of my experiment reinforce my stance on glues.  I will
continue to use hot glue on all interior work on pianos, organs,
organettes and orchestrions.  It has ideal characteristics.  It is easy
to use, is clean and quick, has good holding power on initial gelling
and tightens the joint as it hardens, is cheap, and in these days of
concern for our environment it is a natural and organic material, and
best of all it smells nice!

Nicholas Simons, GB