Sikaflex 291 LOT Slow Cure Adhesive Sealant 10. 3oz 300ml Cartridge Black. Sikaflex 291 LOT is a 1-component, marine grade polyurethane elastomeric adhesive and sealant. It is a moisture cured, non-sag system designed with a long open time for jobs that require more time. Uses General all-purpose, high strength marine sealant, which may be used for light duty bonding with long open time capability for humid climates or jobs requiring more time that remain permanently elastic. Characteristics Advantages Use above and below water line. Resists salt water. Paintable and sandable. Excellent bond. NSF approved for potable water. USDA approved for incidental food contact. Sikaflex 291 LOT Slow Cure Adhesive Sealant 10. 3oz 300ml Cartridge Black. Sikaflex 291 LOT is a 1-component, marine grade polyurethane elastomeric adhesive and sealant. It is a moisture cured, no n-sag system designed with a long open time for jobs that require more time. Uses General all-purpo