Product Data Sheet

DOWSIL™ 3363 Insulating Glass Sealant is a premium two-part, neutral-cure silicone sealant engineered for use as a secondary seal in high-performance insulating glass (IG) units. Designed specifically for demanding architectural glazing applications, this high-strength sealant delivers exceptional durability, structural performance, and weather resistance for modern commercial façades and structural glazing systems.

Developed for high-load insulating glass applications, DOWSIL™ 3363 provides significantly higher design strength than conventional silicone IG sealants, allowing manufacturers to reduce joint dimensions while maintaining structural integrity. Its high-modulus formulation helps minimize stress on the primary seal and supports economical joint sizing in applications exposed to high wind loads, hurricane conditions, cold-bent glass stress, and blast-resistant glazing requirements.

The sealant offers excellent primerless adhesion to glass, coated and reflective glass, aluminum spacers, galvanized steel spacers, stainless steel spacers, and many thermoplastic spacer systems. It is suitable for both double- and triple-glazed gas-filled insulating glass units and meets EN 1279 requirements for gas retention and insulating glass durability.

DOWSIL™ 3363 cures into a durable, high-modulus silicone rubber that resists UV exposure, ozone, moisture, temperature extremes, and long-term environmental aging. Its excellent weatherability and low water absorption help maintain insulating glass performance and structural reliability over extended service life in exterior façade systems.

Designed for automated production environments, the two-part system is dispensed through standard airless mixing equipment and offers a fast cure profile with approximately 5–10 minutes of working time and handling strength achieved within about two hours. Its fast-curing properties help improve manufacturing productivity while maintaining consistent quality and seal integrity.

Common applications include:

• Secondary sealing of double- and triple-glazed insulating glass units
• Structurally glazed insulating glass systems
• High-rise curtainwall façades
• Hurricane- and blast-resistant glazing systems
• Cold-bent and oversized glass assemblies
• Commercial and high-performance architectural glazing applications