The Flex Glue commercial looks incredible: a super strong adhesive that can do it all. But does it really work that way? The TV commercials show Flex Glue lifting more than 1,000 pounds, working underwater and even gluing an entire 4x4 together. Inside Edition went to the Grove School of Engineering in New York City to get some help from two professors, chemical engineer Raymond Tu and mechanical engineer Ali Sadegh. First they carried out the cinder block test.