Sikaflex®-291 LOT
Sikaflex®-291 LOT is a non-sag 1-component polyurethane sealant specifically developed for the marine market, which cures on exposure to atmospheric moisture. It is designed for applications that require additional working time.
- Use above and below water line
- Bonds well to a wide variety of substrates
- Elastic
- Non-corrosive
- Can be overpainted and sanded
- NSF registered, Proprietary Substances and Nonfood Compounds (black and white)
PRODUCT BENEFITS
- Use above and below water line
- Bonds well to a wide variety of substrates
- Elastic
- Non-corrosive
- Can be overpainted and sanded
- NSF registered, Proprietary Substances and Nonfood Compounds (black and white)
Usage
Sikaflex®-291 LOT is a multipurpose sealant for the use in marine applications where a long working time is necessary such as for bedding-in of teak plank decking laid on top of the sub deck surface. It is suitable to make elastic, vibration-resistant joint seals, and can also be used for a variety of interior sealing applications. Sikaflex®-291 LOT bonds well to the materials commonly used in marine construction like wood, metals, metal primers and paint coatings (2-C systems), and fiberglass. Sikaflex®-291 LOT must not be used to seal plastics that are prone to stress cracking (e.g. Plexiglass, Polycarbonate, etc.). This product is suitable for experienced professional users only. Tests with actual substrates and conditions have to be performed ensuring adhesion and material compatibility.Packaging
| Cartridge | 300 ml |
| Unipack | 400 ml |
| Tube | 3 oz |
Product Details
| Chemical base | 1-component polyurethane | |
| Color (CQP001-1) | White, black, mahogany | |
| Cure mechanism | Moisture-curing | |
| Density (uncured) | depending on color | 1.46 kg/l (12.2 lb/gal) |
| Non-sag properties | Good | |
| Application temperature | ambient, product | 5 ─ 40 °C (41 ─ 104 °F) |
| Skin time (CQP019-1) | 4 hours A | |
| Curing speed (CQP049-1) | (see diagram 1) | |
| Shore A hardness (CQP023-1 / ISO 48-4) | 45 | |
| Tensile strength (ASTM D412) | 1.3 MPa (190 psi) | |
| Elongation at break (ASTM D412) | 550 % | |
| Service temperature (CQP513-1) | -40 ─ 90 °C (-40 ─ 194 °F) | |
| Shelf life (CQP016-1) | 12 months B |
| CQP = Corporate Quality Procedure | A) 23 °C (73 °F) / 50 % r.h. | B) stored below 25 °C (77 °F) |
CURE MECHANISM
Sikaflex®-291 LOT cures by reaction with atmospheric moisture. At low temperatures the water content of the air is generally lower and the curing reaction proceeds somewhat slower (see diagram 1).
Diagram 1: Curing speed Sikaflex®-291 LOT
CHEMICAL RESISTANCE
Sikaflex®-291 LOT is generally resistant to fresh water, seawater, diluted acids and diluted caustic solutions; temporarily resistant to fuels, mineral oils, vegetable and animal fats and oils; not resistant to organic acids, glycolic alcohol, concentrated mineral acids and caustic solutions or solvents.
Application
Surface Preparation
Surfaces must be clean, dry and free from grease, oil, dust and contaminants.
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®-291 LOT can be processed between temperatures (climate and product) of 5 °C and 40 °C (41 °F and 104 °F) but changes in reactivity and application properties have to be considered. The optimum temperature for substrate and process material is between 15 °C and 25 °C (59 °F and 77 °F). Sikaflex®-291 LOT can be processed with manual, pneumatic or electric driven piston guns.
Tooling and finishing
Tooling and finishing must be carried out within the skin time of the product. It is recommended using Sika® Slick. Other finishing agents must be tested for suitability and compatibility prior the use.
Removal
Uncured Sikaflex®-291 LOT may 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 a suitable industrial hand cleaner and water.
Do not use solvents on skin.
Overpainting
Sikaflex®-291 LOT can be painted after formation of a skin. If the paint requires a baking process, best performance is achieved by allowing the sealant to fully cure first. 1C-PUR and 2C-acrylic based paints are usually suitable. 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.