I have used many different shellac thinners.  I find denatured alcohol
is unreliable between various brands.  I don't want spend the money to
buy "Everclear" ethanol for [dissolving] shellac.  I will save that for
spiking the punch bowl at church parties.

However, I do use what the old guys used in the olden days.  I purchase
a 5-gallon can of methanol from my local chemical company.  It is less
than $10 per gallon that way; more like $6, I think.  This makes the
shellac flakes melt faster and I only get blush on extremely damp days.

Methanol or wood alcohol has a definite way of inhibiting one from
drinking it: it makes you go blind permanently.  So don't drink it.
I wouldn't drink anything in my refinish department either.

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