I have front and back tongue and groove pine porch ceilings that are 15 years old. The front porch ceiling was whitewashed with a watered down water based stain 15 years ago. I have cleaned several times and power washed it as well with Concrobium and it's ready to be finished. It gets foggy where I live along a river. It has been getting grey mildew on it for several years (not bad but enough to see the grey on the wood). I do not want to use anything to finish it that will attract mildew and I do not want to paint it. I also do not want to ever again have to strip it to recoat. Any suggestions? The back screened in porch ceiling has never been finished, I just cleaned it with Concrobium and am ready to finish it, but again I do not want to have to redo often or strip off old finish when it is in need of redoing. I am thinking either an oil stain or some type of clear oil? I do not want to put anything on it until I know for sure, so I am stuck!