Captain Tolley's Creeping Crack Cure 60ml is a flexible polymer based treatment for leaks from hairline cracks in all caravan and boat building materials. Does not harm polystyrene, and it's transparent when dry and can be painted over. As an added bonus it's non toxic and flexible! Captain Tolley†s was created by Peter Tolley Jordan, an ex captain with 30 years of experience at sea. By skippering boats in all conditions he discovered that most leaks weren†t caused by large obvious gaps but by small, hard to fix, hairline cracks often hidden to the eye Thinking cap put on and Captain Tolley's Creeping Crack Cure was born! Thinner than water, this magical formula draws into the cracks using a capillary action, once in place it forms a strong and waterproof seal. Find the crack, it must be narrower than 1mm wide Clean any dirt or grease from the area and ensure it is as dry as possible If using outdoors the conditions must be dry and frost free Apply sparingly direct from the bottle in 30 minute intervals until crack is filled Wipe away excess immediately Rapid absorption indicates a large leak so check the product isn†t flowing through and dripping out of the other side! Repeat after 24 hours to ensure effective sealing For less accessible, overhead or vertical jobs inject with a syringe Remove dried excess with a rag damped with either white spirit, turpentine or methylated spirit