Recently I bought a 32 Once bottle of 91% isopropyl alcohol at
Walgreen's drug store for a couple of dollars.  I didn't have any
shellac to test it but it did a good job of dissolving exterior
rubber base paint.  In fact it was just as effective as my can
of Ace Hardware labeled "Denatured Alcohol, for shellac thinner
and chafing dish fuel".

Bill Chapman
La Quinta, California