CRL M64 Black Modified Polyurethane Construction Sealant Sausage Pack

• One-part modified polyurethane construction sealant with smooth finish and primerless adhesion on most common construction surfaces, including KYNAR® coated metals
• AAMA approved
• VOC compliant — only 9 g/L
• UV resistant / non-yellowing

CRL M64 (SKU: M64SBL) is a one-part, moisture-curing, gun-grade modified polyurethane sealant formulated for durable, flexible performance in moving joints. Primer is not required on most common construction substrates. M64 offers long-term flexibility and adhesion for perimeter joint sealant applications in storefronts, curtain walls, windows and doors, and general construction sealing.

CRL M64 Modified Polyurethane Construction Sealant is designed to outperform traditional solvent polyurethanes for sealing moving joints in concrete, masonry, metal and other perimeter joints. Ideal for framing-to-structure joints in storefront and curtain wall systems to maintain a watertight installation.

Excellent adhesion to fluoropolymer metal coatings including KYNAR®, Duranar®, and Duranar® Sunstorm™, as well as standard metal, aluminum, steel, galvanized steel, plastics, vinyl, glass, wood, concrete, brass and other common building substrates. Compatible with insulating glass sealants when used as toe or heel beads. Suitable for manufacturing uses such as travel trailers, mobile homes, and galvanized HVAC ductwork assembly.

Paintable after 2 hours with water-based paints. Service temperature (after full cure): -75°F to 300°F (-59 to 149°C). Low-temperature gunning and application above 0°F (-18°C).

• Exceptional adhesion to KYNAR® coated metals — primerless adhesion on many substrates
• Low VOC — only 9 g/L (chemically curing < 3%)
• Solvent-free, isocyanate-free; qualifies for LEED EQ indoor air quality credit
• Permanently flexible — resists hardening with age and remains flexible in low temperatures
• Fast curing: skins over in ~30 minutes; cures ~1/8" (3 mm) per day
• Tooling time ~20–40 minutes (dependent on temperature and humidity)
• UV resistant — non-yellowing for exterior exposure

CRL M64 conforms to and passes Federal Specification TT-S-00230C Type II Class A and ASTM C920 (Type S, Grade NS, Class 25). Also meets multiple ASTM standards and CAN/CGSB-19.13-M87 Type MCG-2-25-A-N (QPL #81026). AAMA 808.3-92 exterior perimeter and AAMA 802.3-92 Type II ductile back bedding compound. USDA approved for use in meat and poultry areas. Meets California Air Resources Board 2003 VOC requirements. Qualifies for LEED® Green Building Rating System™ credit.