What is the best to seal my sponsons

[samcrimm]

I know that this is not related to boats per say, but I have made sponsons with aluminum and foam, I need input and ideas to seal these up. I have thought about flex seal, fiber glass(too much work) and that is all I can come with. And I need your help and input. I have attached pictures so you understand what I am doing.
Thanks

 

[airshot]

I use a product calked " leak stopper" it is a clear, after drying, rubbery plastic sealer used on roofing repairs. Tough stuff, used it on my badly chewed up jon boat hull and it hasn't leaked a drop in the past 6 years. Availiable at home depot and tractor supply, also see it on Amazon. Not sure how well it will work on your foam, testing would be needed.

 

[samcrimm]

looked that up and that sounds like it will do what I want! And yes test it on the foam, Thanks airshot

 

[samcrimm]

I use a product calked " leak stopper" it is a clear, after drying, rubbery plastic sealer used on roofing repairs. Tough stuff, used it on my badly chewed up jon boat hull and it hasn't leaked a drop in the past 6 years. Availiable at home depot and tractor supply, also see it on Amazon. Not sure how well it will work on your foam, testing would be needed.

So far I am find in this only in tubes, I have found other brands that claim to do the same so I guess I will try with them. Thanks again.

 

[airshot]

The stuff I have comes in a blue colored quart size can. Just looked it up and it appears they now have a black versuon which I have not used, supposed to have a fiber in it. Walmart shows the blue cans of the clear stuff I have used. Whether you want the fiber stuff is your call, all I can say is, the ribs on my jon boat were actually worn thru, cracks on the very points that leaked like a seive...coated both inside and outside with numerous coats of leak stopper, still gets dragged over sand and stones with O leaks and that was about 6 plus years back. Clear when it dries, reminds me of a clear rubber like feel but tough. Also used some on my barn roof about 7-8 years back, still there and no leaks. Best stuff I have found, but doesn't mean there isn't something better for you out there.