re: Best varnish for exterior door & beams?

I just refinished the Cyprus columns around my house (10 of them). The original painter of our house recommended Farrell Calhoun Spar Varnish. Can't speak to the durability yet, but the finish turned out beautifully. I rolled it on, but can be brushed. Best of all was the price...little over $30 a gallon. One gallon should do for a door. They have a store in the shopping center at the corner of Seigen and Perkins. Good luck.