Hi all, I need some clarification as to what this particular finish
is.  I always thought it to be shellac but now I wonder if it could
be something else instead, like maybe cellulose?

I have come across it on the old pianos many hundreds of times and I
just encountered it again yesterday on an old cabinet phonograph.  It
is often completely dull and sometimes has a million very tiny cracks.
Often, it is still glossy on the inner parts or in the corners near
the mouldings.

When running sandpaper or a fingernail over it, it immediacy seems to
go to a yellowish colour, and the sanding dust smells most peculiar.
It comes off easily with paint remover / stripper and on many occasions
a bit of sanding will take it right off with that peculiar dust and
smell.

I am not 100% sure but, whatever it is, it seems to have had colouring
in it as well, as once it is stripped off the wood is lighter and not
that much sanding is required after stripping as opposed to wood
stained with a stain before polishing (new stain, that is).

Surely you other folks have encountered this and can tell me if it is
shellac like I always thought of something else?  If it is shellac,
then it must have gone bad as no new shellac smells or sands the way
this finish does.

If it is shellac, then did they put colouring or stain onto shellac in
the old days (1920-1940)?  Did they spray it on?

Best regards,
Bernt Damm
Sydney

 [ Del Fandrich, the piano designer, writes: "The hand-rubbed finish is
 [ usually nitrocellulose lacquer.  This material is quite easy to work
 [ with, just remember that it is extremely flammable -- explosive even
 [ -- so take care.  It also stinks and it's not real good for your
 [ insides.  You will need lots of ventilation, both to reduce the fire
 [ danger and to reduce the wear and tear on your lungs and your brain."
 [ Ref. http://www.lungster.com/l/speakers/pianofinish.shtml  -- Robbie