[ Ref. Roger Wiegand in 200816 MMDigest ]

Here are some comments about the sealing of wood.  Most player pianos
are at least 90 years old and have been in hostile environments, with
severe warpage, dried out and the strength is gone.

As it gets older, shellac becomes brittle, cracks and crystallizes.
You've got to make a decision as to how to make repairs.  Remember,
you can't make or change the dimensions of the board 'cause if you
do some of the air holes will be out of alignment as well as the
countersunk holes.  Re-drilling the holes to clean or remove the
shellac may change how the board is warped, possibly breaking out
the hole.

If you have cabinet-making skills and woodworking tools, such as
a wood lathe, drill press, disk and belt sander, you can copy the
dimensions from the old board to the new board. You need a special
Forstner drill bit to make the pouch hole.

Go to Menard's building supplies.  They have cabinet wood of all
types: https://www.menards.com/ 

You will have no trouble with a new piece of wood.  You can use your
own techniques.  I use a brass tube cut to 1 inch long, with half
in the hole and the rest to connect to the vacuum hand pump which
I bought at the auto parts store.  I slip the clear plastic tube on
the brass tube and add the Phenoseal sealant in the pouch hole until
it runs out the other end.  I use an air compressor regulated to
5 pounds pressure.

Add the sealant to the pouch hole until you see it on the other end.
Hold your thumb on the pouch hole and apply the air.  You will feel
the pressure try to left your thumb.  You may see some of the sealant
on the next hole, which means there is some leakage in the wood.
Wood has blood vessels, too!  Do all 88 pouches and let dry overnight.

Put the vacuum hand pump on the brass tube.  Hold your thumb on the
pouch hole.  Now hand pump and watch the dial on the vacuum pump gage
go up to about 15" water gage vacuum.  It will go higher if you pump
more.  If the gage stays the same, there are no leaks.

I have a comment: if you use a vacuum sweeper its function is to put
air in motion.  If you turn off the motor power there is no vacuum.
When you use the vacuum hand pump the gage shows vacuum reading but
there is no air in motion.  The vacuum sweeper has partial vacuum,
the hand pump has positive vacuum.

The name of the sealer is "Phenoseal".  This is a vinyl sealer.  It is
used in the building industries for water sealing.  It is supplied by
John Tuttle, https://www.player-care.com/  and by Steve's Piano Service
http://www.stevespianoservice.com/ 

S. Lee Walker 
Franklin, Indiana

 [ MMD articles about Phenoseal are indexed at
 [ https://www.mmdigest.com/Archives/KWIC/P/phenoseal.html 
 [ -- Robbie