Galoots,
Previously it was written in part:
> One way is to use "absolute alcohol", and this
>is what I would do if I could.  But I can't, so I try to dry my own.  But
>that's for a future post.

In days past water was removed from alcohol by methods of azeotropic
distillation which left traces of nasty chemicals in the alcohol.  Not good
by today's standards.

A Galoot-friendly method is to use "molecular sieves".  These "sieve"
materials are adsorbent crystalline zeolites in the form of pellets or
beads with tiny "holes" in them that you can hardly see.   (:

There are three types commonly available - called 4A, 5A, and 13X with
holes of 4, 5, and 13 Angstrom, and all are suitable for our purpose.  All
will remove alcohol from other substances, but they like water best!

They can be bought from many scientific reagent suppliers, or you may be
able to track down some discarded material.  They are used to remove water
and certain gases from infra-red equipment, and this is a possible source.
Bags of the sieve are placed into the IR instruments, and purged with dry
nitrogen to keep a clean spectrum and to protect components from moisture.
Some manufacturers recommend that these be replaced every six months, and
the old ones are thrown out.  Some "re-charge" them by removing from the
open-weave bag and heating, and they are as good as new.  Better than new,
in fact, as new mol. sieve should be dried before use if there is any
question of it's history.  Try a university science lab for discards.

To regenerate used mol. sieve, it should be heated for a few hours in an
oven or furnace to between 150 and 300 degrees centigrade, with cooling in
an empty desiccator preferable.  A word of caution for used sieve - find
out what the ms was used to dry in it's previous life.  As it is heated the
residue will be forced out of apparently dry sieve.  Best is the stuff used
in IR instruments, or for drying gases (even refrigerant gases, I now
remember).  Even if only alcohol has been dried, it will be forced out as
it's heated.  And another lesson I learned in the School of Hard Knocks is
that you can fill the space in an oven with alcohol fumes, and when the
door is opened, you can end up with a spectacular eyebrow-singeing ball of
fire!!  The safest approach is to soak the ms in water for a day or so,
drain off, let dry, then heat in the furnace.

Don't be tempted to rely on the fact that water boils at 100 c, and that
should be enough.  We had a postdoc who didn't appreciate this until I took
his regenerated-at-105 sieve and put it in a furnace at 250c.  He couldn't
believe the water condensing on the furnace above the door (it holds at
least 15% of water).  He ended up having to replace a $1500 beam splitter.

Sorry, Mom's - back to the point.

I'm sure there's a reasonably easy method to determine if the alcohol is
dry, but I can't think of one right now (Add to dried copper sulphate, pot.
permanganate?? GC(ms)/TCD?  Anyone?).  But if you work on 5 to 8% water,
and 15% adsorption, then you can work how much ms you'd need to dry a
certain volume of ethanol (easy if you're metricated).  Of course if you
need only to determine if it's over "proof" or not (about 50%), then all
you need to do is to wet some gunpowder with the alcohol.  Apply a lighted
splint, and if it goes "POOF", you have your proof!

Dry the ethanol by adding the cool dry ms to it in a sealed bottle.  Leave
for a day or three, mixing occasionally.  Regenerate and repeat if
necessary.  Then carefully decant off the dry alcohol directly into your
shellac container.  Don't shake or mix first, or fines may be carried over.
 Unless you have a ready supply of ms, I wouldn't put any in with the
shellac solution, or the shellac will have to be washed off before the next
regeneration.

I'm close to the wind topic-wise, but I reckon that in this case the end
justifies the means.

Keep your alcohol dry,
Paul