CRL Aluminum Grainy Polyurethane Construction Sealant Cartridge

• One-part grainy textured modified polyurethane sealant with primerless adhesion on most common construction substrates, including KYNAR® coated metals
• AAMA approved
• Low-VOC — only 9 g/L (chemically curing < 3%)
• UV resistant / non-yellowing

CRL M66 (SKU M66AL) is a one-part, moisture-curing, gun-grade modified polyurethane construction sealant engineered for moving joints in storefronts, curtain walls, concrete, masonry, metal, and perimeter framing applications. It provides durable, permanently flexible performance and excellent adhesion to fluoropolymer paint coatings such as KYNAR®, Duranar®, and Duranar® Sunstorm™, as well as standard metals, aluminum, steel, galvanized steel, plastics, vinyl, glass, wood, concrete, and brass.

Basic Uses
Formulated to outperform traditional solvent polyurethanes, CRL M66 is ideal for sealing moving joints between frames (door and window) and building structure to create watertight installations. Compatible with insulating glass sealants when used as a toe or heel bead. Suitable for interior and exterior use and for manufacturing applications (travel trailers, mobile homes, ductwork assembly). Withstands service temperatures after full cure from -75°F to 300°F (-59°C to 149°C). Paintable with water-based paints after two hours.

The light grainy texture blends with textured substrates like stucco and masonry and helps hide tooling marks on smooth metal storefront joints.

FEATURES / Differentiators
Exceptional primerless adhesion to KYNAR® coated metals — ideal for metal storefront and curtain wall sealant applications.
VOC compliant at only 9 g/L — low-VOC sealant that qualifies for LEED EQ credit.
Eco-friendly: solvent-free, isocyanate-free.
Permanently flexible; remains flexible in low temperatures and will not harden with age.
Fast cure: skins in ~30 minutes; cures ~1/8" (3 mm) per day. Tooling time approx. 20–40 minutes depending on conditions.
Low-temperature gunning and application above 0°F (-18°C).
UV resistant — will not yellow from sun exposure.

Technical Data / Compliance
Conforms to Federal Specification TT-S-00230C, Type II, Class A; ASTM C920-98 Type S, Grade NS, Class 25; and numerous ASTM standards including C510, C639, C661, C679, C717, C719, C793, C794, C1183, C1193, C1246, D412,