I recently purchased a 12 ft jon boat that the previous owner informed me had a small leak. Upon inspection of the boat, I found that the leak was from around a poor repair job on one of the supports (not exactly sure what to call it)that runs from one side of the boat to the other between the 2nd and 3rd seats. The support had cracked on the raised part and was allowing the floor to warp. Whoever attempted to repair it riveted it to the floor and tried to seal around the rivets with what appears to be clear bathroom caulk. I am hoping to replace this and was wondering if there was any place where this kind of part could be found, and if there was a proper proceedure to prevent the leak from re-occuring. (epoxy around rivets, maybe an industrial epoxy or glue instead of rivets, ect... 
)
)