Description
Sika 221 Adhesive & Sealant – 300ml Multi-Purpose Polyurethane
Sikaflex 221 is a high-strength polyurethane adhesive and sealant designed for flexible bonding and permanent sealing across construction, transport, marine and industrial applications.
Widely used for vehicle bodywork, caravans, campervans, metal fabrication, panel bonding and general assembly, Sikaflex 221 provides durable elastic adhesion on metals, plastics, wood, composites and painted surfaces.
Its non-sag formula makes it suitable for vertical and overhead applications while maintaining excellent vibration and weather resistance after cure.
Tested to ASTM C920 and Federal Specification TT-S-00230C, and classified to ANSI/UL 723 for surface burning characteristics, Sikaflex-221 offers dependable performance in demanding environments.
Common Uses for Sikaflex 221
Sikaflex 221 is commonly used for:
- Caravan and motorhome sealing
- Campervan conversions
- Bonding aluminium trims
- Sealing vehicle body panels
- Trailer assembly
- Marine sealing applications
- HVAC and ventilation systems
- Bonding composite panels
- Interior fit-out work
- General industrial sealing and fabrication
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Sikaflex 221 Suitable Substrates
Sikaflex 221 bonds well to:
- aluminium
- steel
- painted metals
- wood
- GRP/fibreglass
- ceramics
- rigid plastics
- composite panels
Key Benefits
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One-component polyurethane sealant and adhesive
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Non-sag consistency for vertical and overhead applications
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Cures to a tough, elastic finish
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High adhesive strength for permanent sealing
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Bonds to a wide variety of substrates
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Ideal for general construction, fabrication, and repair work
Available Colours
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Grey
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White
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Black
Sikaflex 221 vs Silicone
Unlike standard silicone sealants, Sikaflex 221 provides stronger adhesive performance and improved mechanical strength, making it more suitable for bonding applications rather than sealing alone.
Sikaflex 221 vs Hybrid Polymer Adhesives
Sikaflex 221 is a polyurethane adhesivehttps://www.adsupply.co.uk/polyurethane-pu-adhesives/, meaning it generally offers stronger mechanical performance than many general-purpose hybrid sealants. However, hybrid polymers may offer improved UV stability in certain exposed applications.
Sikaflex 221 vs Sikaflex 522
Sikaflex 221 is widely used as a general-purpose polyurethane adhesive and sealant, while Sikaflex 522 is often chosen where improved weathering and environmental resistance are priorities.
