Flex Seal dries in varying time frames depending on the product and application method. For example, Flex Seal liquid dries in 24-48 hours, while Flex Tape sets in 24 hours. Spray-on Flex Seal takes 12-24 hours to dry, and brush-on Flex Seal dries in 2-4 hours. In hot or humid conditions, drying times may be shorter; in cold or wet conditions, they may be longer. It’s recommended to allow adequate drying time before exposing Flex Seal to water or heavy use.