All this talk of finishes on wooden planes has sparked a question.

Is there an easy "flowchart" type way of determining what kind of finish is
on a plane (or anything for that matter)?

I think I heard that alcohol will dissolve shellac, but not varnish or poly.
That mineral spirits will dissolve both varnish and shellac, but not poly.

I could be way off here. Any tips or websites that help you identify a
finish?

Matthew Groves