CRL Black Smooth Polyurethane Construction Sealant Cartridge

• One‑part smooth‑finish formula with 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: M64BL) is a one‑part, moisture‑curing, gun‑grade modified polyurethane construction sealant engineered for durable, flexible performance in moving joints. It typically does not require a primer on common substrates and is ideal where long‑lasting, low‑VOC sealing is required.

Basic Uses
CRL M64 Modified Polyurethane Construction Sealant is formulated to outperform traditional solvent polyurethanes for sealing moving joints in concrete, masonry, metal, and perimeter joint applications. Recommended for joints between framing (door and window) and building structure in storefront and curtain wall systems to ensure a watertight installation. Excellent adhesion to fluoropolymer metal coatings including KYNAR®, Duranar®, and Duranar® Sunstorm™ as well as standard metals, aluminum, steel, galvanized steel, plastics, vinyl, glass, wood, concrete, and brass.

Compatible with insulating glass sealants when used as a toe or heel bead. Designed for exterior and interior use. Service temperature after full cure: -75°F to 300°F (-59 to 149°C). Paintable after two hours with water‑based paints.

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

FEATURES
Exceptional adhesion to KYNAR® coated metals.
Low‑VOC — only 9 g/L (chemically curing < 3%).
Eco‑friendly: solvent‑free, isocyanate‑free, VOC compliant; qualifies for LEED EQ indoor air quality credit.
Low‑temperature gunning and application above 0°F (-18°C).
Service temperature: -75°F to 300°F (-59°C to 149°C).
Permanently flexible — resists hardening with age and remains flexible in low temperatures.
Fast cure — skins over in ~30 minutes; cures ~1/8" (3 mm) per day.
Tooling time: approximately 20–40 minutes (varies with temperature and humidity).
Paintable with water‑based paints after two hours.
UV resistant — non‑yellowing with sun exposure.

Technical Data
CRL M64 conforms to and passes:
Federal Specification TT‑S‑00230C, Type II, Class A.
ASTM C920‑98, Type S, Grade NS, Class 25, Use NT, M, T, A, G, and O.
Also meets ASTM C510, C639, C661, C679, C717, C719, C793, C