Range of choices:1. Nothing- maybe the oil (would be my choice). White oak resists rot tight grain won't absorb much. You'll get a nice patina.2. Spar varnish is the traditional treatment but requires periodic renewal. I'm not a fan of the orangey color.3. Epoxy probably best performance if you don't mind turning your wood top into a plastic one. I think they look awful.
Wood treatment for outdoor countertop
