I think I may be about to "stir the possum" or "put the cat among the
pigeons" here.  A couple of months ago I asked for, and received, some
very good advice about the correct travel for the three cross valves in
the pedal power governor in my Steck Half Duo-Art.  During an exchange
of emails with one of my advisors (hello there, Bruce), I mentioned
that I was not planning to remove the lower valve seats in order to
replace their burnt shellac sealer.  Bruce's comment about this was
very tactful, but I got the impression that he didn't think it a good
idea.

I should mention that this player is one I bought about thirty-five
years ago.  I suspect that it has been in Hobart, Tasmania, ever since
it was exported from the U.S., soon after its manufacture.  I have
pulled apart only a handful of player actions; but this one has less
corrosion than any of the others.  Many of the wood screws have no
visible rust at all on them.  I think Hobart's climate is kind to
pianos.  The relative humidity spends most of its time between 40% and
50%, and the temperature range is rarely outside about 5C to 30C (that
is about 40F to 85F).  It doesn't get near the top of that range very
often, and the temperature range inside a house would be a good deal
less.

The lower valve seats looked to be in excellent condition, with almost
no marks of any kind on the surfaces that mate with the leather
facings, and the burnt shellac looked shiny and uncracked.

However, Bruce had got me a little worried; so I got out my flow gauges
to see if I could measure the leakage.  The only practical way to do
this that I could devise was to measure the leakage with the releath-
ered valve sitting on the bottom valve seat, but with the top cross
valve seat removed, and to apply positive pressure of 20 inches water
column to the top.  The leakage rates seemed to be between 400 and 500
milliliters per minute.  This sounds like a lot, but remember that the
valve was just sitting on the lower valve seat without the upper stem
guide in place.  I had of necessity sealed up all other apertures in
each valve well.

I then applied a couple of coats of shellac to the inside of each valve
well, including everywhere except the mating surfaces of the seats, and
measured the leakage again.  Now the rates ranged from 350 ml/min to
500 ml /min.  I concluded that wherever the leakage might be, it wasn't
around the lower valve seats.

After polishing these seats I did give each of them a quick spray with
3M No. 3900 Clear Protective Coating, on the grounds that modern leath-
er may well be tanned with chemicals that are less kind to metal sur- 
faces than was leather eighty years ago.

The point of all the above is that I have yet to dismantle the upper
action.  There I will be faced with eighty-eight lower valve seats.  If
they look to be in as good a shape as those in the pedal power gover-
nor, I will be very unwilling to dismantle them.  I invite your com-
ments or howls of derision.

John Phillips
Hobart, Tasmania