Product Description

BOSS 383 Weather Seal Silicone Sealant

Eliminates the Use of Frame work for Mirror Fixing Weather Seal Silicone Sealant is an one part neutral cure, medium modulus, lowodor, construction grade sealant that offers excellent adhesion, weather ability and compatibility with wide variety of materials. BOSS ® 389 is ideally suited for weather proofing, waterproofing, sealing, expansion & control joints and general purpose glazing. It has excellent adhesion to glass, glazed surfaces, galvanized steel, anodized aluminum, concrete, cement, wood, ceramics, painted surface and many plastics.

BOSS 383 Weather Seal Silicone Sealant meets or exceeds the requirements of the following specifications:

• ASTM C920-86,
• TT-S-001543A and
• TT-S-00230C.

FEATURES:

• One Part , no mixing required
• Easy to apply
• Excellent adhesion to most common building materials
• Low Odor
• Non-Corrosive to metal
• Permanently Flexible
• Weatherproofs / Waterproofs
• UV resistant

TYPICAL PROPERTIES
Uncured
Specific Gravity	1.40
Colors	Black, Grey and White
Sag/Slump	NIL
Tack-Free Time	> 90min
Cure Time at 75°F (24°C) and 50% RH (3/8 thickness)	24 hours
Full Cure time	7- 10 days
Tooling time	25-30 min
Extrusion Rate	275 g/min
Cured Physical
Elongation	375%
Durometer Hardness, Shore A, points	25
Tensile Strength, psi	195
Dynamic Movement Capability Cycled at 1/8 hr.1/8min.%	± 30

Exceptional Weather Protection

BOSS 383s advanced formulation ensures robust sealing and superior weatherproofing for construction expansion joints and building exteriors. Its neutral cure system and high elasticity make it ideal for long-lasting performance in both interior and exterior environments, protecting against rain, UV exposure, and temperature changes.


Versatile Application Surfaces

This single-component paste adheres strongly to a wide range of surfaces including glass, aluminum, painted metals, concrete, masonry, and modern composite panels. Its compatibility simplifies project planning and reduces the need for surface-specific sealants, thus streamlining purchasing and inventory for suppliers and builders.


Simple and Efficient Installation

BOSS 383 is available in 280 ml cartridges and 600 ml sausages, allowing for easy application using standard caulking tools. It cures rapidly, achieving a tack-free finish in about 15 minutes, while its excellent elastic recovery ensures joints maintain flexibility and coverage over time without shrinkage or cracking.