KEDA · S300

S300 Weatherproof Facade Silicone Sealant

Weathersealing for Facade and Exterior Joints

KEDA S300 is a neutral silicone sealant intended for non-structural exterior joint sealing. It is positioned for facade contractors, installers and distributors reviewing a sealant for weather-exposed joints in the building envelope.

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Product Values

Exterior Joints

Facade Weatherseal

Neutral Cure

Non-Structural Use

Technical Parameters

Product technical parameters
Product Model	S300
Composition	One-component silicone polymer-based sealant
Curing Mechanism	Neutral moisture cure
Appearance	Non-sag paste
Density	0.95–1.05 g/mL (ISO 1183-1)
Skin Formation Time	≤20 min at 23°C / 50% RH
Cure Rate	≥2 mm / 24 h at 23°C / 50% RH
Shore A Hardness	20–30 after full cure (ISO 868)
Tensile Strength	≥1.0 MPa (ISO 37)
Elongation at Break	≥400% (ISO 37)
Movement Capability	±25% (ISO 9047)
Application Temperature	+5°C to +40°C
Service Temperature	−40°C to +150°C

Application & Packaging

Application Areas

Weathersealing joints between compatible facade panels.
External weatherseals in assessed glass curtain-wall systems.
Exposed perimeter joints around windows, doors and adjoining facade elements.
Replacement of existing exterior sealant after the cause of joint failure has been identified.

Suitable Substrates

Approved facade and perimeter joint substrates.

Packaging

Pack format: Cartridge
Illustrated capacity: 300 ml
Carton quantity: Order-specific
Custom options: Fill volume, colour and private label packaging

Usage Instructions

Review the joint and failure history. Confirm the selected product, substrate condition, expected movement and approved joint design. For replacement work, investigate the cause of failure before resealing.
Prepare the bonding surfaces. Remove old sealant and contamination by a method compatible with the assembly. Bonding surfaces must be sound, clean and dry. Use only approved cleaners and primers; do not assume a universal primer-free application.
Set the joint depth. Install compatible backing or bond-breaker material as required by the design. Avoid three-sided adhesion in movement joints. Keep designed drainage and ventilation paths open.
Apply a continuous bead. Use the specified dispensing method and fill the joint with adequate contact against both bonding faces. Avoid gaps, trapped voids and a thin cosmetic layer over failed sealant.
Tool and finish. Finish within the confirmed working period and remove masking tape while appropriate. Use only a tooling method permitted for the actual product; do not assume that soap solution or solvent is acceptable.
Protect, inspect and record. Protect the fresh joint as instructed. Distinguish skin formation from full cure and readiness for movement or testing. Complete the specified inspections and adhesion checks, and retain batch and application records.

FAQ & Limitations

How is S300 different from S200?

S200 is positioned around general window and door sealing. S300 is positioned around exposed facade weathersealing joints. This is an application distinction, not evidence that S300 has a higher movement rating or better performance in every situation. Select using the actual product data and joint requirements.

Can S300 bond curtain-wall glass structurally?

No. This page covers weathersealing, not the structural bond that secures glass. Structural glazing requires a separately specified adhesive, system design and project assessment.

What is its movement capability?

A verified movement classification is not available in this draft. Submit the project requirement for review. Do not use elongation at break or another manufacturer's classification as S300's movement rating.

Does neutral cure mean alkoxy, low odor or oxime-free?

Not automatically. Confirm the exact chemistry and relevant safety information for the supplied formulation. Neutral cure is not a substitute for those details.

KEDA PRODUCT ENQUIRY

Discuss Your Facade Sealing Project

Share your materials, application, performance requirements, preferred packaging and expected quantity. KEDA can propose a suitable product configuration for S300 Weatherproof Facade Silicone Sealant.

KEDA S300 Weatherproof Facade Silicone Sealant