CRL Polyurethane Sealant Cartridge - Off-White Smooth Construction Caulk

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

CRL M64 is a one-part, moisture-curing, gun-grade modified polyurethane construction sealant formulated for durable, flexible performance in moving joints. It typically requires no primer on common substrates and offers long-term adhesion to fluoropolymer-coated metals such as KYNAR®, Duranar®, and Duranar® Sunstorm™, as well as to aluminum, steel, galvanized steel, plastics, vinyl, glass, wood, concrete, brass, and other common building materials. SKU: M640FW.

Basic Uses
CRL M64 is engineered as a low-VOC polyurethane sealant for sealing moving perimeter joints in concrete, masonry, metal, storefronts, curtain walls, doors and windows, and insulating glazing toe/heel beads. Suitable for interior and exterior applications, it withstands service temperatures from -75°F to 300°F (-59 to 149°C) and is paintable after two hours with water‑based paints. Also used in manufacturing travel trailers, mobile homes, and galvanized HVAC ductwork assembly.

Features

• Exceptional adhesion to KYNAR® and other fluoropolymer-coated metals
• VOC compliant — only 9 g/L (chemically curing <3%)
• Solvent-free, isocyanate-free; qualifies for LEED® EQ credits
• Low temperature gunning and application to 0°F (-18°C)
• Permanently flexible — resists hardening with age and remains flexible at low temperatures
• Fast cure — skins in ~30 minutes; cures ~1/8" (3 mm) per day
• Tooling time approx. 20–40 minutes (depending on temp/humidity)
• UV resistant — will not yellow from sun exposure
• USDA approved for use in meat and poultry areas

Technical Data and Approvals
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 ASTM and CAN/CGSB standards listed on the product data sheet, AAMA 808.3-92 exterior perimeter, AAMA 802.3-92 ductile back bedding compound, and CARB 2003 VOC requirements. Qualifies for LEED® credits. Check the Specification Data Sheet for full test listings and certification details.

Limitations
Do not apply to