You seem to have pretty innovative ideas from experience. I got a 33 bert, yes its a camper. Its a shoebox joint which holds the cap on, thru bolted with 1/4-20's through the aluminum rub rail. Alot of the bolts i can't get to, i want to seal it as best as possible with out removing the whole rail. I was thinking a quick and dirty approach , plasti dip slathered from the inside over the joint and 1/4-20's..... what are your thoughts ?
Maybe another (ex) builder's advice will help. Is it leaking because that section took a shunt sometime in its life? Had the builder used an appropriate sealant (3M's 5200, for instance), that and the 1/4-20s likely would've been a permanent thing.
There really isn't a band aid that'll fix this. If it is leaking because of a local impact, you could get away with pulling the rub rail a foot or some past the problem area, reef out the old sealant, and properly seal that area. If, however, it is the factory sealant that's letting go due to age, you probably have a significant project ahead.
The repair is all the more difficult due to this type of joint. As the deck is lowered alongside the hull, there is a tendency for the sealant to be displaced. There actually is a lot to be said for the strength and reliable seal that the simple flanged hull with the deck resting on it provides.
Maybe I'm too old school and there really is some shake & bake product out there that'll solve this for you but I'm doubtful about a quick and dirty fixes for something like this.
BTW, Travis isn't the only builder here and perhaps someone else will weigh in on this while he changes the water in his pots.