CRL Tan Grainy Polyurethane Sealant Cartridge for Construction Joints

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

CRL M66 (SKU: M66T) is a one-part, moisture-curing, gun-grade modified polyurethane construction sealant formulated for moving joints. It typically requires no primer on common construction substrates and provides durable, permanently flexible performance for exterior and interior perimeter and glazing joints.


Basic uses: CRL M66 Modified Polyurethane Construction Sealant is designed for sealing moving joints in concrete, masonry, metal and perimeter framing. Ideal for storefronts, curtain walls, door and window perimeters, and insulating glass toe/heel beads. The advanced polymer bonds to fluoropolymer paint coatings including KYNAR®, Duranar®, and Duranar® Sunstorm™, as well as aluminum, steel, galvanized steel, plastics, vinyl, glass, wood, concrete, brass and other common substrates.

CRL M66 is compatible with insulating glass sealants, paintable with water-based paints after two hours, and withstands service temperatures from -75°F to 300°F (-59°C to 149°C). The light grainy texture matches stucco and masonry and helps conceal tooling marks on metal storefront joints.

Also suitable for manufacturing applications such as travel trailers, mobile homes, and galvanized HVAC ductwork assembly.

Features / differentiators:

• Exceptional adhesion to fluoropolymer/KYNAR® coated metals — primerless on most substrates
• Ultra-low VOC (9 g/L) — solvent-free and isocyanate-free, qualifies for LEED EQ credit
• Permanently flexible — remains flexible in low temperatures and resists hardening with age
• Fast curing — skins over ~30 minutes, cures ~1/8" (3 mm) per day; tooling time ~20–40 minutes
• Paintable with water-based paints after 2 hours
• UV resistant — non-yellowing for exterior exposure
• Low temperature gunning and application (above 0°F / -18°C)

Technical data
Conforms to Federal Specification TT-S-00230C Type II Class A and ASTM C920 Type S Grade NS Class 25 (Uses NT, M, T, A, G, O). Meets numerous ASTM test methods and CAN/CGSB-19.13-M87 (QPL #81026). AAMA 808.3-92 and AAMA 802.3-92. USDA approved for use in meat and poultry areas. Meets California CARB 2003 VOC requirements.