I see a lot of the guys who bash it haven't even tried it but doubt it because it's an "As seen on TV product". GRANTED, most of the stuff is cheap junk... I've used Flex-Seal and it does work.. Like with any spray on product, prep is key. Once you have a clean toothy surface you apply LIGHT coats, don't cake it all on at once. Apply several light coat layers allowing a few minutes between coats like as if you were spray painting. The back of the can even suggests applying it this way. If you cake it on, it's never going to cure/bond correctly like with any sealer product. My guess is the people with negative reviews probably didn't do the correct prep and caked it on.
It's available at Lowes and a couple of other stores local to me so I picked up a can. Used it as a temp fix on a couple of slow leaky rivets on my boat and didn't have a problem. *I have since replaced those couple of leaky rivets!!* But at the time of replacement, the Flex-Seal did hold up (removing it wasn't fun though). I replaced the rivets for peace of mind as the flex seal was only used for a temp repair, but it did work and it probably would have held up for a while who knows.
However after examining it, it seems it's nothing more than a glorified version of rubberized spray automotive undercoating, which also works great for sealing a slight leak. Just so I don't get yelled at by anybody, I should add that the "real" way to fix a leak/hole on an alum boat is to pound the rivets, replace rivets, alum sheet patch + rivets, weld etc! I've heard good things about Gluvit & similar products but never tried it so I can't vouch, sounds like good stuff though. But for an inexpensive quick temp fix till you have the time, sure try it! If you only have a leaky rivet, it will do the trick till you get around to a more permanent repair.
Now, if your boat has a HOLE in it.... this isn't for you, obviously. As much as I had success with the product, that screen door on the boat bottom is very very far fetched haha. But if you have a slow leaky rivet, it can't hurt to try. That''s just my $ .02 and experience with it not looking to start a Flex-Seal debate lol. However I think they should send me a free can or something for my good words about it. :mrgreen: :roll: Just kidding.
Sorry for the long reply I just get uneasy when I see guys bashing products that they admit they haven't even tried.. :roll: :mrgreen:
-Mike