CRL M66 Black Modified Polyurethane Construction Sealant Sausage Pack

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

SKU: M66SBL

CRL M66 is a one-part, moisture-curing, gun-grade modified polyurethane construction sealant formulated for primerless adhesion on common substrates. Durable and permanently flexible, M66 resists weathering and maintains movement capability in perimeter and storefront joints.

Designed for sealing moving joints in concrete, masonry, metal and typical perimeter joint applications. Ideal for door and window framing, storefronts and curtain wall installations to create a watertight seal. Excellent adhesion to fluoropolymer-coated metals (KYNAR®, Duranar®, Duranar® Sunstorm™) and to aluminum, steel, galvanized steel, plastics, vinyl, glass, wood, concrete, brass and other common building substrates. Compatible with insulating glass sealants when used as a toe or heel bead. Suitable for interior and exterior use, and for manufacturing uses such as travel trailers, mobile homes and HVAC ductwork assembly.

Service temperature after full cure: -75°F to 300°F (-59°C to 149°C). Paintable after two hours with water-based paints. Light grainy texture blends with stucco, masonry and smooth metal storefront joints to hide tooling marks.

• Exceptional adhesion to KYNAR® coated metals — primerless on most surfaces
• Low-VOC, eco-friendly formulation — solvent-free, isocyanate-free, 9 g/L VOC; qualifies for LEED EQ credit
• Permanently flexible — remains flexible in low temperatures and won’t harden with age
• Fast cure — skins over in ~30 minutes; cures ~1/8" (3 mm) per day
• Tooling time: ~20–40 minutes depending on temperature and humidity
• Paintable with water-based paints after 2 hours
• UV resistant / non-yellowing for long-term exterior durability

CRL M66 conforms to Federal Specification TT-S-00230C Type II Class A and ASTM C920-98 Type S Grade NS Class 25 (Use NT, M, T, A, G, O). Meets numerous ASTM standards and CAN/CGSB-19, 13-M87 (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 CARB 2003 VOC requirements.

• Do not apply over damp or contaminated surfaces
• Use with adequate ventilation
• Not recommended for surfaces with