Marine Crackseal instructions 1. If possible identify the source of the leak. 2. Introduce Crackseal by means of the spout. 3. As Crackseal makes its way into the crack, repeated applications may be required. 4. Use masking tape or putty to prevent Crackseal from running out of the other side of the crack. 5. Allow to dry (transparent). Should Crackseal re-absorb moisture before fully hardened it will blanch, but when conditions permit it will cure clear. Glueing using Burgess Crackseal Apply a light coat to both surfaces and clamp firmly together for at least one hour. Wipe away excess Crackseal before drying.