I sympathize with everybody who has, in the past, tried to use shellac
to seal the end grains of wood-- particularly hardwoods. As Larry
Broadmoore wisely pointed out, you can pour that stuff in till you
are blue in the face, and you will still get leakage. Unless the
shellac is "burnt" (hot pot) shellac, made from button shellac, and
containing a large amount of natural lac wax, you are going to have
problems later on.
If you happen to have an old Ampico valve block, you'll notice it is
shiny with a thick, solid coat of shellac on it. Try this: Wet one
side with your tongue and then make a seal around that side with your
lips and give it a big smooch-- suck hard on that side! Put your tongue
lightly against the side of the block while you're doing it, and you'll
usually (or quite often) feel this fine "fizzing" buzz, as air is being
drawn through what appears to be solid shellac. It tickles your tongue.
Take that leakage and add to it about 85 more, and you have quite a bit
of leakage that you didn't expect. But there is definitely one way to
stop that leakage cold-- Phenoseal.
Don't think that you can go down to just any old hobby store or hardware
and buy it. It is especially good stuff. A friend of mine had a neighbor
who had a fancy fountain put in his yard and the bowl leaked. He called
the installers two or three times and they never could seal it with the
stuff they normally used, so he took my idea of using Phenoseal in
players and poured Phenoseal into it-- to this day it hasn't leaked
another drop. But what it does to wood is perfect-- it gets absorbed
first, then it dries and because it is flexible, it cannot be degraded
by the inter-pore movement in the wood. A bubble jar is all you really
need to see how absolutely tight you can make things using it.
I was the person who told Durrell Armstrong about Phenoseal in the
first place. I had been having problems with wood sealing for years.
Sealing flat grain is easy-- about anything will do. But sealing the
end grain in pouch wells or on stacks-- that's something else again.
There are two different "weights" of Phenoseal. I buy the "Concentrate."
That way, I can always thin it. It isn't cheap, by the way. In channel
stacks, you can cover the holes and fill the chambers with the stuff,
let it sit awhile, and then pour it out. It will be cartridge tight
It is made by the Gloucester Co. Inc. Franklin, MA 02038. You can
order by phone if there isn't a dealer close to you. Ask for item #203.
(I don't have the phone number right now)
I have never tried sealing cloth with either Phenoseal or PVC-E glue,
however. I believe I would try something else, first. But about the
question of removing PVC-E glue-- that's not hard at all. Either hot
water and a scrub brush or lacquer thinner and a scrubber will do it
very nicely (depending). It will also dry sand off using a belt sander.
It is very compatible and easy. What I dread is carpenter glues
(yellow aliphatic resin glues). Even Elmers white glue isn't half as
bad as these. After the plastic glue is washed off, you can go back
with hot hide glue.
Size the pieces first, just to make sure you'll have no lifting
problems. For pneumatics, bundle them in stacks and size their edges
with thinned down hot hide glue, first. let them (mostly) dry, and
separate them to harden fully. Now you're ready to cover them again.
If you are afraid you can't see the glue well enough, tint it with
food coloring first (an old trick I've used for years. When I would
seal pouch leather in the skin, I'd tint the sealant with something,
say analine dye stain-- that way you know which skins are sealed and
ready to go. You know you can use them for whatever by the colors
you've coded them with. Some players had red pouches, and it gave me
The reason I do not like some PVC-E glues for pneumatics is its softness.
If there is a constant weight or pressure on a pneumatic (like a pedal
operator), PVC glue might "creep." But worse, PVC glue does not rigidly
support the pneumatic hinge as it should. As a result, pneumatic leaf
action is not crisp and straight up and down. It skewers around,
depending on the sideways forces encountered on the way up. That isn't
how you want a pneumatic to work. Use hot hide glue. Learn how to use
it, and then use it all the time. It gells to set, assuring you of a
perfectly air-tight bond.
Tip: If you are using cotton/rubber cloth and would like to double the
working life, glue the rubber side inboard. That works well, for sure.
From there, you might try treating the cotton with some of these silicone
deck sealants, like Thompson ( I wonder??). I've never tried that. It
may preserve the rubber greatly, but don't take my word for that.