CRL 33S Tan Silicone Sealant - Window & Glass Sealant

• Our best-selling silicone with special additives to resist mold and mildew
• Plastic cartridges with screw-on nozzles for easy application
• Available in eight colors
• 24 month shelf life*
• 10 year limited warranty

This is our most popular sealant. CRL 33S Silicone (SKU: 33ST) is a one-component, room-temperature curing, acetic-cure 100% silicone elastomer that delivers professional-grade performance without added activators, stabilizers, or catalysts. It’s formulated for mildew resistance and long-term durability in building and sanitary applications.


Basic Uses - CRL 33S Silicone is designed for joining and sealing most non-porous building materials including glass, aluminum, stainless steel, wood, and many plastics. For best results, clean all surfaces and tool the sealant for good adhesion. Cat. No. S1L2100 primer may be required on some substrates. Ideal long-tail uses: silicone sealant for windows and curtainwalls, silicone for showers and bathtubs, silicone for refrigerated trucks and walk-in freezers, and general-purpose glazing and weatherproofing.

Performance & Temperature Range - Wide operating range of -80° to 400°F (-62° to 204°C). Can be applied at outdoor temperatures as low as -35° to 140°F (-37° to 60°C). Typical physical properties: 350 psi tensile strength; 120 psi lap shear at 1/8" (3 mm) thickness; tear strength 25 ppi. Suitable for curtainwall joints, steel and aluminum windows, skylights, and many sanitary installations. Mildew-resistant colors (clear, white, translucent white, tan) contain a fungicide for cured beads.

Limitations - Not recommended for structural glazing or insulating glass glazing, concrete and stone expansion joints, horizontal decks, patios, driveways or terraces subject to abrasion, submerged joints (swimming pools and aquariums), or certain metals and coated surfaces. Not suitable for painting. See cartridge label and Specification Data Sheet for full limitations.

Comparable Sealants - Dow Corning®: 999-A; 786; 732; 700; Glazing Silicone; General Purpose; Commercial Grade 100%; Tub, Tile and Ceramic, HVAC/R. Dap: 100% Silicone. GE®: 1200 Construction, 1000 Contractors, 1700 Sanitary. Tremco®: Proglaze, Tremsil 200, TremPro 644. OSI: HM-270. Pecora: 860, 863. Sika®: SikaSil® GP. Sonneborn: OmniPlus.

Technical Data - Meets or exceeds federal specifications:
TT-S-001543A (COM-NBS) Class A, for Silicone Building Sealants
TT-S-00230C (COM