I live in Biloxi, so I know of the humidity problem you speak of. Living across the street from the beach , I also have to fight salt-air. My storage room is not air tight, so I had to find a solution also. I picked up a few of the large plastic storage containers with lids from Wal-Mart. I was able to put most of my parts (with the exception of large body parts) in these. They also stack up nicely. They come with small vent holes under the molded handles. I just taped over these to seal them. Large engine parts, I oil and double bag with black plastic bags. As for large body parts; I make sure they are stored off the ground, paint them with a rust prohibitve paint, and check them occassionally for surface rust. It's not easy living with the fishes.