Quote Originally Posted by Dan Jansen View Post
I'm pretty new to the whole HVLP spray finish scene but I picked up a used Sprayfine fairly cheap. I've used it to spray some typical Minwax Polyurethane and got good results by thinning it slightly but it takes so long to dry. Is there a trick to getting it to cure faster? More thinner or should I try a different product?
Varnishes "dry" in two phases: First the volatile components (including any thinner) evaporate leaving the resin/oil solids behind, and then the solids cross-link (chemically bond) to form a solid film. The second part is what takes so long, and mucking with the volatiles by adding thinner etc won't do a thing to change it.

What you want here is finish that quickly cures to a point where it can be handled/recoated/sanded and doesn't attract dust. There are two basic ways to do that:

1. If you want to stick with oil-based varnishes, then step up to a catalyzed finish of some sort. The catalyst greatly accelerates the cross-linking process.
2. Change to a finish that cures by a different mechanism, for example one that cures by evaporation (lacquer, shellac) or by coalescing (many non-catalyzed waterbornes).