>[ Can someone please tell us the properties and typical uses of
>[ (1) silicone grease, (2) silicone oil, (3) silicone glue, and
>[ (4) silicone rubber?  -- Robbie

The uses and properties are very much like those of "regular" grease,
oil, glue, and rubber.  The difference is that instead of being made up
of carbon chain molecules, they're made up of silicon chain molecules.

Silicon forms chains that are a lot like those of carbon, but they
tend to be a good deal more resistant to breakdown by heat, time,
light, contaminants, and other factors.

A grease is just oil that's been absorbed into another compound, often
a metallic soap of some kind, so it retains most of its lubrication
qualities but is not liquid.  The soap may also contribute extra
lubrication or preservation qualities of its own.

Rubbers are long-chain molecules that are good and tangled up.  If you
take an oil and treat it so its chains get real long and joined in
weird ways, you'll get a rubber.  There are lots of kinds of rubber:
natural rubber (made of long carbon chains with sulfur bonds between
them), silicone rubber (made of long silicon chains), and weird ones
like the rubberized plastics we use in high-voltage power cables.

A glue is any liquid which will wet other solids and then turn to into
a solid itself when we want it to.  I believe that most silicone glues
are thick liquids which turn into silicone rubber.  The RTV stuff I use
on my truck engine certainly is.

From my reading of the discussions here in MMD, my sense is that the
big objection to silicone compounds is because, being resistant to
breakdown by most solvents or heat or time, you can never get rid of
them.  And when you work with traditional, carbon-based materials like
wood and leather, silicone compounds tend to sink in and sort of take
over the works.  It's a matter of materials compatibility, and is in
some respects an artistic issue.

Of course, I don't know what a pouch is.  I'm sort of guessing that
it's the actual air actuator: a diaphragm that the air sucks in and
out, and it's connected to some sort of actuating rod to strike the
hammer on the piano string.

And what's zephyr skin?  Are zephyrs endangered?

Mark Kinsler,  who also doesn't know what a "stack" is.

 [ Ooop!  Where's the "Player Piano Frequently Asked Questions (FAQ)"
 [ when we badly need it?  :)  -- Robbie