I recently built my first kayak (stitch and glue). I painted the hull and varnished the deck. I used West System epoxy to seal the deck, and finished it with four coats of Z-Spar Captain's Varnish. I was very pleased with the finish of the boat on completion. The varnished deck looked great. Later, we put in the water and played all weekend and it sat in the sun for a while also. When I brought it back home to clean and store, it still looked great. I hung it up under my car port for about two weeks and looked at it daily. It still looked great. Then one day I took it out to play, and the deck varnish had large faint cloudy or milky spots. The spots got much worse during the weekend, so I figured I would need to sand it down and refinish. But after a week or so in storage, the cloudy areas disappeared. They seem to come and go, possibly according to the weather. Can anyone explain to me what is happening, how I can fix it, and most importantly, how to avoid this problem on my next boat? Thanks