KD998 High-Performance Silicone Weatherproofing Sealant for High-Rise Buildings

KEDA KD998 High-Performance Silicone Weatherproofing Sealant

KD998 is a single-component, neutral cure, room temperature vulcanizing (RTV) silicone sealant with high modulus and high movement capability. Specifically engineered for weatherproofing and joint sealing in high-rise glass curtain wall applications, it delivers exceptional weather resistance. The product has undergone rigorous accelerated aging tests with no significant deterioration in physical and chemical properties, demonstrating excellent long-term performance retention.

Single-component System: Neutral cure at room temperature, ready to use
High Modulus: Superior structural stability for demanding high-rise applications
Superior Mechanical Properties: Excellent elasticity, elongation, and tensile strength
Exceptional Weather Resistance: Outstanding resistance to harsh climatic conditions and temperature extremes
Proven Durability: Passed various accelerated aging tests without performance degradation
Universal Adhesion: Excellent bonding to most building materials
High Movement Capability: Accommodates building movement and thermal expansion

Applocation

Weather sealing for high-rise glass curtain wall systems
Weather sealing for metal aluminum panels and ceramic curtain walls
Joint sealing for skylight and roofing constructions
Perimeter sealing for commercial high-rise buildings
Expansion joints in tall structures
Various other demanding weatherproofing applications

Package

Cartridge Size: 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

Ensure all substrates are clean, dry, and free from contamination, dust, oil, grease, and loose particles
For porous substrates, ensure they are sufficiently dry
Remove any old sealant, paint, or coatings that may interfere with adhesion

Step 2: Joint Design

Use appropriate backer rod or bond breaker tape for joints deeper than 12mm
Recommended joint width-to-depth ratio: 2:1
Ensure three-sided adhesion is avoided

Step 3: Application

Cut the cartridge nozzle at a 45° angle to desired bead size
Load cartridge into a professional caulking gun or power applicator
Apply sealant evenly and continuously into the joint
Ensure complete joint filling without air pockets

Step 4: Tooling & Finishing

Tool the sealant surface within 10-15 minutes of application before skin formation
Use a spatula or smoothing tool moistened with soapy water
Remove masking tape immediately after tooling if used

Step 5: Curing

Allow adequate curing time: typically 7-21 days for full cure depending on joint depth
Protect from rain and moisture during initial 24 hours
Avoid stress or movement during cure period

Additional information

Product Type	Single-component neutral silicone sealant
Modulus	High
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
Movement Capability	±25%
Hardness (Shore A)	30-45
Tensile Strength	≥1.0 MPa
Elongation at Break	≥400%
Tensile Modulus at 100%	0.6-0.9 MPa
Aging Resistance	Excellent (proven through accelerated tests)

Limitation

NOT for structural glazing applications (use Thor KD999 structural sealant instead)
NOT suitable for materials that exude oils, plasticizers, or solvents
NOT recommended for poorly ventilated or confined spaces
NOT suitable for surfaces in direct contact with food or potable water
NOT recommended for continuous water immersion or permanently submerged applications
DO NOT apply when substrate temperature is below +4°C or above +50°C
NOT paintable (silicone does not accept paint or coatings)
NOT compatible with bituminous surfaces or materials containing copper

Tips

For Best Results:

This product is specifically formulated for high-rise building applications
Conduct adhesion tests on actual substrates before full-scale application
For critical high-rise projects, follow building codes and consult with structural engineers
High modulus provides superior wind load resistance for tall buildings
Document all accelerated aging test results for project specifications
Maintain quality control records for high-rise installations
In cold weather, store sealant at room temperature before use

Quality Assurance:

Perform regular visual inspections during application
Verify proper adhesion and continuous bead application
Monitor curing conditions (temperature, humidity)
Document installation for building maintenance records

Storage & Handling:

Keep cartridges upright during storage
Rotate stock using FIFO principle
Once opened, use within one month
Protect from freezing temperatures