One thing I learned the hard way was to treat the wood thoroughly with both oil and varnish before installing the bed pieces. I originally used what was advertised as a high quality outdoor urethane varnish, but it only lasted a year before it started to lift. I took the wood out again, stripped, sanded and then used three coats of Watco Danish wood oil. After drying and light sanding I applied three coats of marine spar varnish. The color, finish and durability is much better.
