Sikaflex 521 UV Weathering Resistant Adhesive and Sealant

Sikaflex 521 UV Weathering Resistant Adhesive and Sealant Overview

Sikaflex 521 UV is a one-component Silane Terminated Polymer (STP) adhesive and sealant designed for long-term durability in weather-exposed environments. With excellent adhesion to metals, ABS, PC, FRP, and wood, it is ideal for both internal and external sealing and bonding applications. This versatile adhesive does not require special pre-treatment and provides elastic bonding with exceptional aging and weathering resistance. Suitable for professional use, Sikaflex 521 UV offers low odor and can be painted or sanded for a seamless finish.

Sikaflex 521 UV Features and Benefits

• Weather and Aging Resistant: Maintains performance in harsh environments.
• Versatile Adhesion: Bonds to a variety of substrates without special pre-treatment.
• Isocyanate- and Solvent-Free: Safer formulation for improved user safety.
• Paintable and Sandable: Provides a smooth, professional finish.
• Low Odor: Ideal for enclosed or confined spaces.

Specifications

• Series: Sikaflex 521 UV
• Chemistry: One-Component Silane Terminated Polymer (STP)
• Application: Elastic Sealing and Bonding
• Substrates: Metals, ABS, PC, FRP, and Wood
• Color: Light Gray, Black, and White
• Cure Mechanism: Moisture-Curing
• Package Size: 10.1 fl oz (300 mL) Cartridge and 20.3 oz (600 mL) Unipack
• Density (Uncured): 11.7 lb/gal (1.4 kg/l)
• Application Temperature: 41°F to 104°F (5°C to 40°C)
• Skin Time: 30 Minutes
• Curing Speed: See Diagram on TDS
• Shrinkage: 2%
• Shore A Hardness: 40
• Tensile Strength: 260 psi (1.8 MPa)
• Elongation at Break: 400%
• Tear Propagation Resistance: 30 pli (5 N/mm)
• Service Temperature: -58°F to 194°F (-50°C to 90°C)
• Shelf Life: 12 Months
• Storage Temperature: Below 77°F (25°C) - Protect from Direct Sun Light

Applications

Sikaflex 521 UV is designed for sealing and bonding in environments exposed to weather and aging. Suitable for use on metals, plastics, FRP, and wood in industrial, marine, and construction settings.