Sika Sikaflex® 221 Multi-Purpose Polyurethane Sealant/Adhesive - 10.3oz(300ml) Cartridge - Aluminum Gray

Sikaflex®-221 Multi-Purpose Polyurethane Sealant/Adhesive in Aluminum Gray is a one-component, moisture-curing sealant and adhesive designed for versatile bonding and sealing across wood, metal, ceramic, and plastics. It’s ideal for construction, maintenance, and DIY projects that require durable elasticity and reliable adhesion.

• Size / Volume: 10.3 oz (300 ml) cartridge
• Color: Aluminum Gray
• Formulation: 1-component polyurethane sealant/adhesive
• Cure mechanism: Cures on exposure to atmospheric humidity to form a durable elastomer
• Non-sag performance: Non-sag formula provides stable, high-adhesion bonding
• Substrate compatibility: Bonds to wood, metals (and metal primers/paint coatings in 2-component systems), ceramics, and plastics
• Elasticity & durability: Highly elastic and durable, with strong resistance to aging and weathering; non-corrosive
• Finishability: Sandable and overpaintable to match surrounding finishes
• Certifications: NSF registered and UL listed for potable water
• Standards: Meets ASTM C920 classifications and ANSI/UL 723 testing for surface burning characteristics
• Applications: Designed for permanent elastic seals with high adhesive strength across substrates
• Regulatory note: Prop 65 warning — contains chemicals known to the State of California to cause cancer or reproductive harm

This sealant/adhesive enables durable, flexible seals and bonds that accommodate movement and environmental exposure. Its one-component formula simplifies application, while broad substrate compatibility reduces the need for multiple products. The sandable and paintable finish helps you blend joints with surrounding finishes, and potable-water certifications provide assurance for plumbing or drinking-water related components. Whether you're sealing windows, joints, countertops, or plumbing fixtures, Sikaflex®-221 delivers reliable performance across projects.