Well, why is it so difficult to understand that there is a very fine
sealant for the wind channels, for every pouch board as well as
individual pouch wells?  Just look at what is there.

The factory installed shellac or burned shellac into the pouch wells.
Over the years this may have cracked, but if you pour fresh shellac
through the chambers and around the pouch well, the seal is back.

Organ Supply Industries (OSI) has a large wooden box with a drain in
it going to a shellac reservoir.  They have a system that pumps the
liquid shellac out of a hose so they can force shellac through every
channel in every pipe organ chest they build.  This has been done this
way for over a century.  They are not pumping Phenoseal through it --
only shellac.

Personally I do not use burned shellac for this as the factory could
set the items on the shelf for several months before use.  I don't
have the time for burned shellac to dry.  I put fresh shellac -- either
commercial shellac canned and thickened, or some I have mixed up using
the flakes and methanol -- into one of my squeeze bottles I use and
sell for hot glue.  I squeeze the shellac through every channel and let
it drain.  In some cases I tape one end of the channel and fill it up.
Then I pull the tape off and let it drain.  Often I must run long, fat
fuzzy pipe cleaners through the holes to make sure there is no excess
shellac.  It must set up to dry overnight afterward.

I had this demonstrated just last week.  I had a Story and Clark stack
that had been restored by another shop.  I replaced the leather that
leaked like a sieve, gapped the valves correctly, and had it all back
together.  However, in testing the stack alone in the piano, there were
many poorly working notes.  Some would not repeat and some would only
repeat if its neighbor was open.  I also noticed several that did not
fully raise the valve so that it played weakly but the outside valve
hissed.

I opened up the pouch board and attached a tube to one pouch while
keeping the others all closed.  I also closed all the bleeds and blew
into one pouch.  The pouch rose easily and upon continued blowing, the
pouches on either side of that one also slowly rose.  This would be
seen by the system as extra bleed or extra tracker bar hole size at
various times in the roll.  I realized that I expected every shop to be
as thorough as ours.  Of course, we had to remove all the pouches and
pour shellac through the channels.

Because of the use of plastic glue I ran the pouch board through the
planer, which took off only the pouches and glue.  We had removed the
old bleeds, of course.  Pouring the channels took about 15 minutes
between the decision to replace and setting it up to dry.  The previous
rebuilder had used way too much glue so the edges of the pouches were
firmly glued in the shape of the belly.  About 1/8" of glue was found
making a border inside the pouch well.  This impeded the pouch action
as well.  The next day when dry, the new pouches were installed in
about an hour, they were sealed and new disks and felt disks installed
in center in another thirty minutes and new bleeds were installed.

When reinstalled in the piano there were only 2-3 bad notes that needed
valve attention and all the other 30 note problems were gone.

As many of you know I don't use something just because it is new.
We don't use bathtub caulk which Phenoseal always has been, and in some
re-restorations we have had to remove that new stuff.  Don't get me
started on that.  Everything we do is what the factory did or would
have done.  We have learned our lessons with synthetic materials decades
ago and now have no use for them.

Stay original and it works.  You will have much less test time as well.

D.L. Bullock
http://www.pianoworld.us/