Description Flex Glue is an easy to use, super strong, waterproof adhesive that instantly bonds, seals, and repairs virtually everything. Flex Glue will grab and hold instantly. Flex Glue is specially formulated to work on all types of surfaces and can be applied on dry or wet surfaces, and can even be applied underwater! Plus, once it's applied, the clear glue will virtually disappear. Flex Glue is solvent-free, paintable, and never runs or drips so it can be applied overhead.