exterior victorian door with several layers of paint. plan to strip, sand with 120, then stain with natural. question is, what product can a diyer use to finish and protect that will last beyond a year or so? pros say that polyurethane or spar varnish will give up in a year or so. door is under a 6 or 7 foot overhang, but faces west. and this is texas heat and sun. are there any oil finishes that you can recommend? or, what do you recommend i do?