Just a few more points about Hydrophane Leather Dressing which arise
from the surprising interest I'm receiving.

Hydrophane Leather Dressing used to be produced by a different, older,
famous grindery company and was universally known among equestrians
simply as Hydrophane, so I'll continue to call it that.  It took me
several months of testing a good few years back to confirm it as the
only viable leather treatment for pouches and I've used it and
recommended it to rebuilders here ever since.  Today's product seems
just as good as the original.  It is extremely well-regarded and tried
and definitely does not rot any kind of leather.

Since it is easily emulsified and removed by ordinary detergents,
I believe Hydrophane Leather Dressing contains no silicone, or only
a very small proportion of low viscosity.  However, having been
involved in materials testing and technology I caution against being
anti-silicone.  Silicones (organic compounds of silicon, the second
most abundant element in the universe) are very inert and stable,
and used right are extremely effective materials.  Invariably it is
inappropriate solvents or dispersing agents or other ingredients
that damage materials and not silicone.  Note that silicones must be
completely removed any if adhesives are to be effective subsequently.

Hydrophane not only by swells the fibres of pouch leather and zephyr
skin, thus making them effectively airproof, but also, unlike latex
and albumen, lubricates them, which increases suppleness.  It is also
fairly temperature insensitive and doesn't thicken, crystallize and
therefore increase much in viscosity in cold climates.  And unlike
some proofers it soaks in and doesn't form a stiffening laminated film
on the surface.

All these factors are what makes it such a harmless and effective
substitute for those air-proofers we know the original manufacturers
used.  It is a mistake to think that simply replacing old pouches and
envelopes will return pneumatic mechanisms to full original performance:
they must be proofed as they were originally, or they effectively
increase the bleed size by some random factor, and soft playing and
repetition are impaired.  And, anyway, there is often no need at all to
replace pouches which are not disintegrating but simply dry and porous:
Hydrophane can make them work just as well as modern replacements.

Patrick Handscombe
Wivenhoe, Essex, UK