Description
Sikaflex 221 White Polyurethane Sealant/Adhesive | Boat Supply Store
For permanent, reliable seals in demanding marine environments, Sikaflex 221 addresses the critical need for superior adhesion and environmental resistance. This 1-component polyurethane sealant cures to a durable elastomer upon exposure to atmospheric humidity, forming strong bonds to a wide variety of substrates including wood, metals, and primed/painted surfaces. Meeting ASTM C920 standards and ANSI/UL 723 tested, it provides exceptional elasticity and resistance to aging and weathering, making it ideal for sealing deck fittings on a Bertram or securing components in saltwater spray zones.
Key Features
- Offers superior adhesion to a wide range of marine substrates.
- Provides high elasticity for durable, long-lasting seals.
- Ensures excellent resistance to aging and weathering.
- Delivers non-corrosive performance in marine environments.
- Features sandable and paintable surfaces for aesthetic finishing.
- Includes NSF registration for potable water applications.
- Boasts UL listing for potable water contact.
- Functions as a versatile sealant and adhesive for multiple repair needs.
Specifications
| Product Specifications | |
|---|---|
| Brand | Sika |
| SKU | CWR67316 |
| MPN | 90891 |
| Cartridge Size | 10.3oz (300ml) |
| Color | White |
| Type | 1-component Polyurethane Sealant/Adhesive |
| Cure Type | Atmospheric Humidity |
| Cure Form | Durable Elastomer |
| Substrate Compatibility | Wood, Metals, Metal Primers/Coatings, Ceramic Materials, Plastics |
| Elasticity | High |
| Resistance | Aging and Weathering |
| Corrosiveness | Non-corrosive |
| Post-Cure Finish | Sandable, Paintable |
| Standards Met | ASTM C920, ANSI/UL 723 |
| Certifications | NSF-registered, UL Listed for potable water |
Who This Is For
Marine enthusiasts, DIY boaters, and professional boat builders and repairers seeking a versatile, durable, and weather-resistant sealant and adhesive for a wide range of applications. This product is engineered for those requiring permanent, reliable seals in demanding marine environments.
How It Compares
| Feature | Sikaflex 221 White Polyurethane Sealant/Adhesive | Competitor |
|---|---|---|
| Type | Polyurethane | Polyurethane |
| Cure Time | Cures on exposure to atmospheric humidity | 24-72 hours |
| Flexibility After Cure | Highly elastic and durable elastomer | Limited flexibility |
| Adhesive Strength | High adhesive strength | Permanent, high strength |
| Weather Resistance | Resistant to aging and weathering exposure | Excellent |
| NSF Registered | Yes (black, grey, and white) | No |
| UL Listed for Potable Water | Yes (black, grey, and white) | No |
Common Concerns Answered
What if I need to remove the sealant later?
Sikaflex 221 forms a permanent, durable bond. While removal is difficult once fully cured, this is indicative of its robust, long-lasting performance essential for critical marine applications. Proper surface preparation ensures optimal adhesion, maximizing its permanent sealing capabilities.
Is surface preparation crucial for Sikaflex 221?
Yes, proper surface preparation is imperative for achieving optimal adhesion with Sikaflex 221. Ensuring surfaces are clean, dry, and free of contaminants is essential for the sealant's long-term performance and durability in harsh marine conditions.
How long does it take to cure?
Cure time for Sikaflex 221 can vary based on ambient humidity and temperature. In typical conditions, it cures upon exposure to atmospheric humidity, forming a durable elastomer. Patience is key, especially in cooler or less humid environments, to ensure a complete and robust cure.
Frequently Asked Questions
What surfaces can Sikaflex 221 be used on?
Sikaflex 221 bonds effectively to a wide variety of substrates including wood, metals, metal primers and paint coatings (2-component systems), ceramic materials, and plastics, making it highly versatile for marine repairs and installations.
Is Sikaflex 221 waterproof?
Yes, Sikaflex 221 cures to form a durable elastomer that is highly resistant to weathering and forms a reliable, waterproof seal, making it suitable for numerous marine applications where water ingress is a concern.
Can Sikaflex 221 be painted over?
Yes, Sikaflex 221 can be sanded and overpainted after it has fully cured, allowing for seamless integration into existing paint schemes on your vessel.
How long does Sikaflex 221 take to cure?
Sikaflex 221 cures on exposure to atmospheric humidity. While specific times vary with environmental conditions, it develops into a durable elastomer, providing a long-lasting seal.
Is Sikaflex 221 suitable for marine applications?
Absolutely. Sikaflex 221 is engineered with high adhesive strength, elasticity, and resistance to aging and weathering, making it an ideal choice for permanent, reliable seals in demanding marine environments.
