Sikaflex

Sikaflex 291i is a multipurpose product used in marine constructions. It is suitable for making elastic vibration-resistant joint seals and can also be used for a variety of interior sealing applications. Sikaflex 291i bonds extremely well to the materials commonly used in marine construction like wood metals metal primers and paint coatings 2-C systems ceramic materials and plastics GRP etc. Sikaflex 291i must not be used to seal plastics that are prone to stress cracking e.g. PMMA PC etc.
Features
Wheelmark approved
1-component formulation
Highly elastic
Low odour
Non-corrosive
Can be painted
Bonds well to a wide variety of marine substrates
Solvent free
Very low VOC
Low isocyanate content
Sealing applications
Chain plates
Deck Fittings & Hardware
Hatches
Ports, etc.
Specifications
Chemical base: 1-component polyurethane
Colours: White, Black
Cure mechanism: Moisture-curing
Density: 1.3 kg/L
Non-sag properties: Good
Application temperature: 10-40 degrees C (ambient)
Skin time (CQP019-1): 60 minutes
Open time (CQP526-1): 45 minutes
Shrinkage (CQP014-1): 2%
Shore A hardness (CQP023-1/ ISO7619-1): 40
Tensile strength: (CQP036-1/ ISO 527): 1.8 MPa
Elongation at break (CQP036-1/ ISO 527): 700%
Tear propagation resistance (CQP045-1/ ISO 34): 7N/mm
Service temperature (CQP513-1): -50 to 90 degrees C, 4 hours 120 degrees C, 1 hour 140 degrees C
Shelf life (CQP016-1): 12 months
Application
Surface preparation

Surfaces must be clean, dry and free from grease, oil and dust.
Surface treatment depends on the specific nature of the substrates and is crucial for a long lasting bond. Suggestions for surface preparation may be found on the current edition of the appropriate Sika® Pre-Treatment Chart. Consider that these suggestions are based on experience and have in any case to be verified by tests on original substrates.

Application
Sikaflex®-291i can be processed between 10 °C and 40 °C but changes in reactivity and application properties have to be considered. The optimum temperature for substrate and sealant is between 15 °C and 25 °C.
Sikaflex®-291i can be processed with hand, pneumatic or electric driven piston guns.

Tooling and finishing
Tooling and finishing must be carried out within the skin time of the sealant. It is recommended using Sika® Tooling Agent N. Other finishing agents must be tested for suitability and compatibility prior the use.

Removal
Uncured Sikaflex®-291i can be removed from tools and equipment with Sika® Remover-208 or another suitable solvent. Once cured, the material can only be removed mechanically. Hands and exposed skin have to be washed immediately using Sika® Cleaner-350H cleaning towels or a suitable industrial hand cleaner and water. Do not use solvents on skin!

Overpainting
Sikaflex®-291i can be best painted after formation of a skin. Painting could be improved by treating the joint surface with Sika® Aktivator-100 or Sika® Aktivator-205 prior to paint process. If the paint requires a baking process (> 80 °C), best performance is achieved by allowing the sealant to fully cure first. All paints have to be tested by carrying preliminary trials under manufacturing conditions. The elasticity of paints is usually lower than that of sealants. This could lead to cracking of the paint in the joint area.