Lacquer is no longer sold in hardware stores in California, Oregon and
Arizona, and perhaps other states.  It is available by order in paint
stores, but only in 5-gallon batches sold for industrial use.  Similarly,
rubber cement thinner is not sold here, but I found it in Chicago.

A piano tech here in California has resorted to buying lacquer in a
spray can which he sprays into a container and then applies it to the
hammer as needed.  What substitutes are being used when hammers require
hardening?

I bought the softest hammers I could find because I prefer the softer
tone.  Very hard hammers could possibly obscure the dynamics of
reproducing instruments, which brings up the subject of psychology of
sound.  It may be the softer hammers were used in the 1920s, and I
guess 78-rpm audio recordings might reveal hammer properties of that
era.  These recordings precede the hi-fi improvements, but in my
opinion, have set off a trend of exaggerated use of sound, including
upper end frequencies.

I recently attended a concert in a smaller auditorium (at a high
school) where a concert grand Steinway was amplified!

Bill Chapman
La Quinta, Calif.