Aluminium Grey Sikaflex 291 Multifunctional Adhesive Sealant in a sausage pack.

Sikaflex®-291 is a non-sag, 1-component polyurethane sealant specifically developed for the marine market, which cures on exposure to atmospheric moisture.

Sikaflex®-291 meets the requirements set out by the International Maritime Organisation (IMO).

Features:

• Bonds well to a wide variety of substrates
• Good ageing and weathering resistance
• Elastic
• Low odour
• Non-corrosive
• Can be over painted
• Can be sanded

Usage

• Sikaflex®-291 is a multipurpose product for use 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®-291 bonds 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®-291 must not be used to seal plastics that are prone to stress cracking (e.g. Plexiglas, Polycarbonate, etc.). Once cured, Sikaflex®-291 can easily be sanded as required.
• This product is suitable for experienced professional users only. Test with actual substrates and conditions have to be performed to ensure adhesion and material compatibility.  

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 for Marine Applications. Consider that these suggestions are based on experience and must be verified by tests on original substrates.

Application

• Sikaflex®-291 can be processed between 5 °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®-291 can be processed with hand, pneumatic or electric driven piston guns as well as pump equipment. For advice on selecting and setting up a suitable pump system, contact the System Engineering Department of Sika Industry.

Tooling and finishing

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

Removal

• Uncured Sikaflex®-291 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®-291 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.