Flex Seal is an adhesive spray that was sold on infomercials by iconic salesman Phil Swift. 

Phil would get up to some wacky nonsense in the commercials, like sawing a hole in a boat and then replacing it with a Flex Sealed door. One time he sprayed a truck with flex seal and then converted it into a submarine. This isn’t an ad for Flex Seal, but honestly, we have to give the product, and Phil, props for going all out.

Swift’s antics have inspired a lot of people to do similarly ingenious, and some incredibly weird and stupid things with Flex Seal.