CRL 1/4" x 1/2" Black Butyl Glazing Tape – Window Sealant

• Age- and weather-resistant butyl rubber formulation
• 100% solids, 0% VOC — no asbestos
• Meets AAMA 804.3, 806.3, 807.3 and ASTM C1281
• Exterior primary spacing and glazing seal for window sashes; available in gray and black

CRL Butyl Architectural Glazing Tape (SKU: GT406) is an extruded, preformed butyl rubber (polyisobutylene) tape supplied on release-paper rolls. Engineered for long-lasting, flexible weather seals, it resists aging, UV exposure, and normal expansion/contraction and wind loading. Use as an exterior primary spacing and glazing seal when glazing glass into a window sash, or to seal metal-to-metal, metal-to-glass, wood-to-glass, and other architectural joints. Designed to compress approximately 10% at installation to accommodate surface alignment and ensure a watertight seal.

Typical Properties
Base Polymer: Butyl rubber (polyisobutylene)
Solids Content: 100% solids (no asbestos)
Cure Time: Fully cured before application
Hardness: 20 Durometer Shore A @ 77°F (25°C)
Temperature Range: Application 20°F (-7°C) to 120°F (49°C); Service -40°F (-40°C) to 190°F (88°C)
VOC Content: 0%
Joint Movement: ±15% of joint width
Service Life: Minimum 20 years

Applicable Standards: AAMA 804.3, 806.3, 807.3; ASTM C1281

Good Glazing Practices
Surfaces must be clean, dry, and free of frost or standing water. Prepare by brushing and solvent-washing (MEK, toluene, or naphtha) and wiping dry. Install with positive contact and about 10% compression to fully marry surfaces. Keep glazing tape under compression with clips or wedges for best sealing. Use 80 Durometer Shore A setting blocks at sill quarter points; use 50 Durometer Shore A spacing shims for lites over 100". Place tape on the sill rabbet at or above the sight line unless a cap bead is specified—then place tape 3/16" (4.8 mm) below the sight line. Do not overlap tape ends; butt without stretching. Keep release paper in place until ready to set the glass.

Product Warning / Limitations
For applications above two floors, use a spacer, shim, or a structural cap bead (such as silicone) to prevent over-compression, or specify CRL 100+ Load