[ Ref. "Filling in the Gaps", 04.02.06 MMDigest

To Eliyahu and group,  The best remedy for over-sanded deck boards is
to make new reproductions, copying the original size.  However, the
following might be helpful for a hobbyist who doesn't have access to
the power woodworking tools necessary for making new decks:

The orchestrion builder J.D. Philipps & Soehne of Frankfurt, Germany,
sometimes found it necessary to rout diagonal slots in the bottom
surface of pneumatic deck boards, to locate pneumatics off-center from
where the channels started at the edge of the deck. This left the deck
not only with channels partially opened to the bottom surface, but with
all channels purposely cut open and wandering sideways beyond the edges
of the pneumatics. The entire bottom surface of each deck was then
covered with heavy paper or seal cloth, with holes punched to align
with the holes in the pneumatics but covering the rest of the slotted
areas.

Something similar also can be used for repairing damaged pneumatic deck
boards.  (Please --- I'm not suggesting that the channels in the old
deck first be cut open with a router, but I feel obliged to mention this
in case someone reads it the wrong way!  I'm only suggesting the use of
the seal.)  It assumes that the old decks are flat enough and that the
total thickness of deck and seal equal the original thickness of the
undamaged deck.  Changing the thickness of the deck boards will also
change the space between decks and consequently the available travel of
the pneumatics.  This might make it difficult or impossible to regulate
the pushrods correctly, unless the difference can be corrected by
changing the thickness of the pneumatic rest felt.

If adding a seal appears to be practical, I recommend something that is
easy to glue on both sides but will stick well with hot glue or liquid
hide glue.  Aeolian used pouch leather originally. If something heavier
is needed, heavier pneumatic leather or thin split suede leather will
also work.  Just be sure to select a leather that won't split. Gently
iron the leather as you glue it down, wait for the glue to dry, and
clamp the pneumatics as you glue them.  The next time the pneumatics
have to be recovered, remove the pneumatics first, then wet the leather
seal and heat it with an iron, which will dissolve the glue and release
the leather without damaging the wood.  At that time it will probably be
time to make new pneumatics and deck boards anyway, something which is
neither uncommon nor particularly difficult, given the right tools.

Art Reblitz
orchestrion@juno.com.geentrop