CRL 777 White Butyl Rubber Sealant – Waterproof Window & Door Sealant

• Excellent adhesion to a variety of clean surfaces
• Superior exterior weathering properties
• Easy to apply and tool

CRL 777 Butyl Rubber Sealant (SKU: 777W) is a butyl-based, age‑resistant sealant formulated for long-lasting exterior performance across temperature extremes. It provides excellent adhesion to most clean surfaces, resists UV degradation with a special ultraviolet inhibitor, and accommodates joint movement of ±10% while maintaining water-tight seals. Ideal as a general-purpose butyl rubber sealant for exterior joints and repairs.


Basic Uses
Recommended for exterior applications where a durable butyl sealant is required. CRL 777 adheres well to wood, masonry, glass, concrete, some plastics, and metal. Typical uses include hidden gaps under sill cans and thresholds, sealing around screw heads, between metal building panels, under aluminum siding and gutters, and around wall‑mounted air conditioning units. Application temperature range: 40° to 120°F (4° to 49°C). Service temperature range: -20° to 200°F (-29° to 93°C). Paint time: 24 hours.

Comparable Sealants
CRL: 888. Adco: B-100, AP-77. DAP®: Butyl Flex. OSI®: SBR-100. Pecora®: BC-158. PTI: 757. PSI: 301. Tremco®: Butyl Sealant.

Technical Data
Meets Federal Specifications TT-S-001657, Type 1, TT-C-1796A, ASTM C 1311, and AAMA 808.3-05; USDA Certified.


Product Warning:

Not recommended for sealing horizontal decks, patios, driveways or terrace joints subject to abrasion or heavy physical abuse. Not intended for window glazing or hidden joint details that require a non-skinning, non-hardening sealant. CRL 777 cures via a solvent-based system; a slight mineral spirits odor is normal during application—do not use where this odor is objectionable (for example, in refrigerated units to be stocked immediately). Check the cartridge label and Specification Data Sheet for additional limitations. NOTE: All colors are available in bulk packaging.