I hear gluvit is good. I used coat-it on the bottom of my boat and 5200 on inside seams.
Coat-it is some good stuff. Little hard to work with, but comes out great when done. Really seals up good and it is pretty cheap. A quart was $20 at academy sports and it did every seam and rivet on the bottom of my boat.
The 5200 is great on inside. But **** it takes forever to fully cure! The coat-it drys in 24hrs.
The good thing about Gluvit is that it flows into the crack or leak to seal it and doesn't just sit on top like the gflex or 5200 seems to do. I think the coat-it may be similar but I don't have experience with it.
