I've got 1500 feet of birch tongue and groove that I'd like to seal. I plan on sealing before I put it up, and seal on both sides. I've been told that sealing before you install is best because you don't get unfinished lines develop as the boards shrink. I've been told to seal the top as well as the bottom to prevent the boards from cupping over time.
Half of this will be on an indoor ceiling, the other half will be on a soffit overhang. We're in Tucson, so very very dry most of the year. We plan on sealing clear to show off the wood.
So the question is what's the best / quickest / least painful method for sealing? I've read about oils (tung, linseed, etc), but 1500 square feet with a day drying time between coats seems like it'll take a year to get through the whole bundle. I was leaning toward spraying a catalyzed lacquer because it would be fast, but I'm a bit concerned about how well it'll hold up in the soffit (albeit it's so dry here that maybe I'm overthinking things?). I've also read about people spraying poly through typical airless paint sprayers. Maybe that's the solution?
Thoughts?