It's a shame that Player Piano Co. no longer stocks #71 bleeds. They
are the correct size to read the tiny perforations in 12/inch pipe
organ rolls.
But there is an easy way to make the holes smaller, if one can get only
PPCo standard #68 or #64 bleeds. This is the same technique used by gas
fitters to reduce the combustion orifices, when converting old
appliances from coke oven gas to natural gas or propane.
One needs a set of wire-size drills, a pin-vice, an old 1/8" drill, and
a hammer. Clamp the 1/8" drill, shank end up, firmly in a bench vice.
Slip the bleed cup over the drill end, and hit it with the hammer.
This will swage the hole closed.
Using the selected wire size drill in the pin-vice, ream out the hole
to the desired size. Hold the bleed in the fingers; the drill will
turn easily by hand. Such a small hole can not be made with any power
drill without breaking the bit.
#71 is probably small, for the Gulbransen, but one can determine the
correct size by trial and error. Then one can learn how many hammer
blows are needed to reduce the hole to below that size. It took me
three good whacks to reduce a standard bleed hole to where a #71 drill
would barely cut metal.
Richard Vance
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