Greetings:

This is in response to Brett Mohr's query regarding the water
manometer. I used a fancy term for a plain old vacuum gauge, an
example of which is described by Reblitz in Player Piano
Servicing & Rebuilding on page 8. My preference would be to make
it direct reading instead of differential. Set up a quart or half
gallon bottle on the back of the workbench with colored water in
it, and stick a 1/4" I.D. clear plastic hose into the water by
several inches. (Don't seal the neck of the bottle - air must be
able to get in.) Take the hose straight up as high as you can (at
least 40" above the water level), then over and down to your test
situation. Tack a yardstick on the wall behind the hose, with the
zero inches end even with the water level in the bottle. If the
hose goes vertically more inches than the maximum your vacuum
source can deliver, you won't get any water into your parts or
vacuum supply. Experiment with smaller or larger I.D. hose until
you get results that you like. And have fun.

I wouldn't worry too much about the mildly disappointing results
of thirty seconds leakdown time for your pump. Try as we might,
there are some systems that have just too many surfaces or
junctions susceptible to leakage. I've seen players work well (as
long as the stack was tight) with pumps that leak down in only
ten seconds . A full minute would be ideal, but 30 seconds is
nothing to be ashamed of.

By the way, do take note of Bob Conant's cogent comments at the
end of his contribution Re: Cable piano motor in the Automatic
Music Digest 96.01.20. I knew I didn't want to have to do much
sucking on old player parts, no matter how much I'd be able to
brag about it afterwards, but I'd forgotten about lead tubing,
and how that innocent looking white dust is eventually
distributed throughout the pneumatic system. The Mad Hatter got
his name by absorbing mercury during the felt-making process in
the 19th century. We can only guess what makes us crazy enough to
work on old player pianos.

Cheers.

Doug Rhodes¶
Victoria, B.C. Canada¶
wo631@freenet.victoria.bc.ca