Hello Steve, I think you'll find turps a highly ineffective and
unsatisfactory solvent for shellac. The best is reagent grade ethanol
(ethyl alcohol aka "grain alcohol"). The second best, and much more
widely available, is industry grade anhydrous denatured ethyl alcohol
(typically 95% enthanol, 5% methanol). For best results what you
definitely want is 0% water in the ethanol.
Note that methanol and isopropyl alcohol are not good second choices
to ethanol. Over-the-counter isopropanol (aka "rubbing alcohol") is
typically cut with at least 30% water and can variously contain
methanol, ethanol, or ethylene glycol. It will usually cause the
shellac to form nasty little balls that are a real bugger to dissolve
properly thereafter. Methanol (aka "wood alcohol") is, of course,
quite poisonous and isn't as good as ethanol anyway.
You might find these links worthwhile: Shellac FAQ:
http://www.shellac.net/faq.html Shellac Finishing by Donald C.
Williams: http://www.alan.net/prgfeat/dwshel.html Padding Shellac By