I need some advice. I have a new pole barn with kiln dried pine rough cut board and batten boards. I want to stain it. However, I don't want to re-stain it every year. What is the best stain? When I say best I want to know what is going to last the longest. I want to be able to still see the grain so transparent or semi-transparent is what I am leaning toward. If I can get 3-5 years without re-staining I will be happy. Anyone have experience with long lasting high quality exterior stain?