1965 Jet Board
Board - Leaks
The above shot is the worst of the corrosion showing large holes through to the foam inside. The board was made of two pressed aluminum skins that were welded at the tail end of the board, and riveted along the lateral seam. The rivets had come loose over time, and the sealing compound at the seam had become brittle.
My first step was to get the corrosion areas down to bare aluminum so that I could use a marine epoxy filler to bridge and seal the holes. The primary idea behind the board was to get it running. Although some people may find a restoration based on this theory not a great idea, we decided the hull was in bad enough shape to warrant major epoxy repair. In the future if someone wants to properly repair the board, nothing we have done has ruined the board in any way.
We used PC-11 marine epoxy to fill the worst holes, and smeared a bead of marine silicon around the side seam of the hulls. The first time we set the board in the water we realized this was not enough to seal the leaks. Although the board has a sump system to evacuate water inside the board, it only works when the engine is running. Finally we decided a coat of marine bondo would work well to smooth out the hull. We used a small can and probably only added 2 lbs to the weight of the board overall.
Once this is sanded down and painted it should look pretty decent. The hull was so beat up that this was the only way to be sure.