A little history. Yesterday I stopped by to do a little diagnosis on a
DA OR, a family heirloom with an interesting history. The goal was to
determine if the piano could be patched into a decent condition or if
it needed a full pneumatic rebuild. It had been "gone over" by a
hobbyist with good intentions but with the experience of a previous
decade, a time when a partial restoration might be all that was needed.
He did a very careful recovering job and replaced all the tubes but had
not worked on the valves and pouches. A few years ago I was called into
try to finish the job. I advised the owner (a friend) that it is not
generally good to do a "partial" job on a piano like this if a good
performance was expected but agreed to try a step by step approach. I
rebuilt the expression box since the theme valves were original and
leaking and rebuilt the pump which was totally gone. I did a complete
job on both and found that the leaking cross valve stack needed to seat
itself as well as the pump valves and suggested that the piano be
played for a while before giving another evaluation. The piano sat for
years during a home remodel and subsequent sale and move .I was called
after this to address a weak playing situation and a slow rewind.

What I found was a piano that could barely play all notes on a level 15
accompaniment code. I checked each of the major components and looked
for major leaks but everything seemed to work independently. The box
could maintain a range of vacuums and the modulator passed full vacuum
etc. but the piano could develop no power at all. Experienced
rebuilders of grands are probably guessing at the reasons by now but
my experience in grands is limited and what ever I have done was
generally with original instruments.

After about 2 hours of attempts to readjust the 0 levels and look for
other problems I was about to admit defeat and send the piano to be
completely overhauled by an experienced pro. Just about then, I
noticed, while crawling out from the piano for the fiftieth time that
one of the legs looked a little uneven at the point where it met the
case frame. The gap was not even. Almost immediately thereafter I found
that three critical small tubes were almost completely crushed between
the leg mount and the frame. By then the pneumatic regulation was
completely gone but after replacing the tubes and resetting the
0 levels, the piano played again like a piano that had sat for years
and needed a good workout. I was pleased that I did not have to admit
defeat and loose a customer and good friend and also felt a little
ripped off by the carelessness of the piano mover who claimed
experience with reproducing pianos. I was not responsible for the
retubing and do not know if I would have routed the tubes the way they
were, but know for a fact that I would never do this on a future job.
I am sure this is not an isolated experience. Piano movers who remove
the legs are not thinking about such details. Brawn is their forte not
brains.

I still need to let the piano break in and do some further test and
expect that the stack valves and others will need to be properly
rebuilt once the owner hears what a Duo-Art (mine) can do under more
favorable conditions.

I hope to remember this experience in the future and make it a point
to route the tubes which can be caught under the treble end leg
(modulator control, stack cut off and spool motor regulator bypass)
through the framing in such a way that a careless mover can not
repeat this error.

Spencer

Spencer Chase
http://www.SpencersErolls.com/