Sorry Jay, I think you've missed the point there. As Brian said, some varinishes will cure rather than dry – to be more precise: "curing" means that there is a chemical reaction taking place rather than a solvent (or water) evaporating leaving behind the hardened varnish. There are many different cure-reactions:
- epoxy resin molecules need a correct amount of hardener molecules they can partner up with
- polyester resins use a catalyst that starts a chain reaction (that's why the mix doesn't need to be as precise as with epoxy)
- polyurethanes usually need a catalyst hardener and/or minute amounts of CO2 or H2O from the air. Most times there will be a solvent involved that speeds up the cure.
- acrylic varnishes cure after the water has evaporated, the same goes for many simple solvent and oil based varnishes

Once a varnish starts to flake or become in any way uneven it's unwise to continue application because the cure has already changed it's structure leading to some unforseeable results.
As a basic rule most 1-component varnishes can usually be rejuvenated (or removed) with a solvent or even water. With 2-component stuff that's usually not the case as the cured end product has changed from loose into a fully cross-linked structure non-accessible by solvents. That's why we have to remove those using abrasives.