KD621 Structural Silicone Glazing Sealant_300ml

KEDA KD621 Structural Silicone Glazing Sealant

KD621 is a single-component, neutral cure, room temperature vulcanizing (RTV) structural silicone sealant with excellent adhesion to glass, aluminum alloy, and other building materials. Widely used for structural bonding and sealing in glass curtain walls and metal construction projects, it delivers exceptional weather resistance and is suitable for long-term use in humid, hot, and marine salt spray environments. With a service life of up to 40 years under normal conditions, it provides reliable structural performance for demanding facade applications. Part of the Swift Series, it offers professional structural glazing performance at competitive pricing.

Structural Grade: Specifically designed for load-bearing structural glazing applications
Safe & Non-Corrosive: Neutral curing formula, non-corrosive to glass, aluminum alloy, and coatings
Exceptional Durability: 40-year service life under normal weather conditions
Superior Adhesion: Excellent bonding to most building materials, typically no primer required
Environmental Resistance: Suitable for humid, hot, and marine salt spray environments
Excellent Compatibility: Good compatibility with other neutral silicone sealants
High Performance: Maintains structural integrity under extreme conditions
Cost-Effective: Professional structural grade at competitive Swift Series pricing

Applocation

Structural bonding and sealing for glass curtain wall systems
Structural glazing for aluminum panel curtain walls
Glass skylight structural bonding
Metal structural engineering applications
Factory or on-site assembly of glass and metal materials
Two-sided structural glazing systems
Four-sided structural glazing systems
Other construction and industrial structural applications

Package

Cartridge Size: 300ml, 590ml
Available Colors: Clear/Transparent, White, Black, Gray, Customized
Packaging Type: Hard tube, Sausage pack/cartridge
Shelf Life: 12 months from production date (in sealed original container)
Storage Conditions: Store in cool, dry place below 27°C

Step 1: Surface Preparation (CRITICAL for structural applications)

All substrates must be thoroughly cleaned and free from contamination, dust, oil, grease, moisture, and loose particles
Clean glass with appropriate solvents and wipe dry
Clean aluminum with isopropanol or approved cleaner
Allow surfaces to dry completely before application
Conduct adhesion tests on actual substrates before production application

Step 2: Priming (if required)

Apply appropriate primer if specified by adhesion test results
Follow primer manufacturer’s instructions for application and flash-off time
Typically, no primer is required for glass and anodized aluminum

Step 3: Joint Design (Follow structural calculations)

Bite depth and width must be determined by structural engineer
Typical bite depth: 6-12mm depending on glass size and wind load
Ensure proper clearance and no three-sided adhesion
Use setting blocks and spacers as per design

Step 4: Application

Cut nozzle to match bite width requirements
Load cartridge into professional-grade caulking gun or power applicator
Apply sealant in a continuous, uniform bead
Ensure complete fill with no voids or air pockets
Work methodically to maintain quality

Step 5: Curing (CRITICAL)

Allow full cure before glass installation: minimum 7 days, typically 14-21 days
Protect from contamination, moisture, and stress during cure
Do not handle or install glass panels before full cure
Monitor environmental conditions throughout cure period

Additional information

Product Type	Single-component structural silicone sealant
Product Series	Swift Series – Structural Grade
Grade	Structural glazing grade
Cure System	Moisture cure (neutral)
Skin Formation Time	10-20 minutes (23°C, 50% RH)
Tack-Free Time	20-30 minutes (23°C, 50% RH)
Curing Speed	3-5 mm/24 hours
Application Temperature	+5°C to +40°C
Service Temperature	-50°C to +150°C
Service Life	40 years (under normal conditions)
Movement Capability	±25%
Hardness (Shore A)	35-50
Tensile Strength	≥1.2 MPa
Elongation at Break	≥300%
Tensile Modulus at 100%	0.8-1.2 MPa
Adhesion Strength	≥0.6 MPa (to glass, aluminum)

Limitation

NOT suitable for materials that exude oils, plasticizers, or solvents
NOT recommended for poorly ventilated spaces during cure
NOT suitable for surfaces in direct contact with food or potable water
NOT recommended for continuous water immersion
DO NOT apply when substrate temperature is below +4°C or above +50°C
NOT for use with certain plastics (conduct compatibility tests)
NOT paintable
ONLY use for structural applications if qualified through proper testing and engineering approval

Tips

Size Selection Guide:

590ml: Best for large-scale structural glazing projects, commercial curtain walls, factory assembly
300ml: Ideal for small structural projects, repairs, field touch-ups, residential applications

CRITICAL – Structural Application Requirements:

Engineering Approval Required: This product must be specified by qualified structural engineer
Mandatory Testing: Conduct adhesion tests on all actual substrates before production use
Quality Control: Implement strict QC procedures for all structural glazing work
Certification: Ensure installers are trained and certified for structural glazing
Documentation: Maintain complete records of testing, installation conditions, and quality checks
Building Codes: Follow all local building codes and structural glazing standards

For Best Results:

Work only in controlled environmental conditions (temperature 15-30°C, humidity 30-70%)
Use professional-grade equipment for consistent bead application
Never compromise on surface preparation – this is critical for structural performance
Allow full cure time – do not rush structural installations
Coordinate with project engineer on all bite dimensions and glass loads
Consider environmental factors: wind loads, thermal cycling, seismic requirements

Swift Series Structural Value Proposition:

Professional structural glazing performance at competitive pricing
40-year service life proven in field applications
Same technical specifications as premium structural sealants
Ideal for large commercial projects where cost efficiency matters
Excellent for contractors seeking quality without premium brand pricing
Marine environment resistant – perfect for coastal projects

Environmental Suitability:

Excellent for coastal/marine environments with salt spray exposure
Performs well in hot, humid tropical climates
Maintains adhesion in freeze-thaw cycling conditions
UV-stable for long-term outdoor exposure

Storage & Handling:

Store in controlled environment
Rotate stock carefully – use oldest material first
Once opened, use immediately or within recommended timeframe
Protect from contamination and moisture

Safety:

Ensure adequate ventilation during application and cure
Wear appropriate PPE (gloves, safety glasses)
Follow all safety data sheet (SDS) recommendations