Re: Leaks when it rains.
I happened to catch part of the TV show How It's Made ? the other day. They were showing a company that builds RV trailers. One of the last steps in the build process was where they brought this blower inside the trailer, and connected the intake to the roof vent. Then they went outside and played a stream of water over all the joints, windows and roof penetrations looking for leaks. So clearly this method can work well. I'll bet some of the boat builders do it too.
Gary H. Lucas