Don mentioned the cable glands to me & that's what I used for the solar system going into the roof. Had to go through the aluminum skin & was worried about leaks. Used Osi Quad caulk to bed them & tightened the nuts. No leaks.
![Image](http://i1176.photobucket.com/albums/x331/Tim_Curry/CableGlands_zpsz4pxjte0.jpg)
On the bottom, I used bushings made from electrical conduit which I drilled & bonded into the deck with epoxy. Ran the conduit through the bushing & sealed the edges.
![Image](http://i1176.photobucket.com/albums/x331/Tim_Curry/Conduit_zpsnidfwqnq.jpg)