Product Data Sheet

DOWSIL™ 983 Structural Glazing Sealant is a high-performance, two-part neutral-cure silicone sealant engineered for structural glazing and weatherseal applications in commercial curtainwall and façade systems. Designed for factory glazing and curtainwall production, this structural silicone forms durable, flexible, watertight bonds capable of supporting glass and panel assemblies while delivering long-term weather resistance.

This architectural-grade sealant is specifically formulated for applications requiring both structural bonding and weathersealing performance in a single product. Once cured, DOWSIL™ 983 develops a high-modulus silicone rubber that accommodates ±25% joint movement while maintaining excellent adhesion, elasticity, and environmental durability.

DOWSIL™ 983 provides exceptional primerless adhesion to glass, anodized aluminum, alodine aluminum, and many painted metal surfaces commonly used in structural glazing systems. It is also compatible with reflective glass, laminated glass, and most insulating glass units, making it suitable for a wide range of modern façade and glazing designs.

The sealant features a customizable cure profile with adjustable mix ratios between 8:1 and 10:1 by volume, allowing fabricators to optimize cure speed and handling time for specific production requirements. Its two-part formulation is designed for use with automated airless mixing and dispensing systems, supporting efficient, high-volume curtainwall manufacturing operations.

Once cured, DOWSIL™ 983 delivers outstanding resistance to UV exposure, ozone, moisture, temperature extremes, and long-term weathering. Its non-corrosive neutral-cure chemistry and excellent recovery after repeated expansion and compression cycles help maintain structural integrity and weatherproof performance over decades of service life.

The sealant meets ASTM C1184 Structural Glazing Specification and ASTM C719 Class 25 requirements for weatherseal applications. When used in approved structural glazing systems following Dow technical review and design guidelines, the product can qualify for long-term structural glazing warranties.

Common applications include:

• Structural glazing systems
• Factory-glazed curtainwall fabrication
• Dual structural and weatherseal joints
• Glass curtainwall assemblies
• Commercial façade panel bonding
• Structural attachment of glass, metal, and panel systems
• High-performance architectural glazing applications