Fasto S890 – Gap Filling, High-Performance RTV Sealant

Fasto S890 is a one-part, low-odour, neutral cure, RTV silicone sealant developed for flexible, durable, and weather-resistant sealing across industrial, electrical, automotive, and construction applications. It cures at room temperature to form a tough yet elastic rubber seal, providing excellent adhesion, moisture resistance, and long-term reliability on a wide variety of substrates.

Its non-corrosive formulation makes it safe for sensitive metals and electrical assemblies, while its paintable surface after curing ensures clean, professional-looking joints in visible sealing areas.

Packaging:

Drum : 290kg

Bucket : 25kg

Cartridge : 300ml

Key Features

One-Part Neutral Cure System
Provides easy application with non-corrosive curing, safe for metals and electrical components.
Low Odour Formulation
Comfortable to use in enclosed or indoor environments.
Excellent Weather & Moisture Resistance
Performs reliably in indoor and outdoor conditions.
High Flexibility & Elongation
Accommodates joint movement, vibration, and thermal expansion.
Paintable After Cure
Allows aesthetic finishing without cracking or peeling.
Wide Substrate Compatibility
Bonds well to metals, glass, ceramics, plastics, rubber, concrete, and wood.

Benefits

Ensures long-lasting, flexible sealing
Protects joints from water ingress, dust, and environmental exposure
Reduces risk of corrosion on sensitive substrates
Maintains seal integrity under vibration and temperature changes
Delivers clean, professional finishes in visible joints

Primary Application	Sub-Applications	Functional Purpose	Key Performance Advantage
Industrial Sealing	Pumps, machinery housings, equipment joints	Prevent leakage & ingress	Flexible, moisture resistant
HVAC & Duct Sealing	Air-conditioning ducts, ventilation systems	Air & moisture sealing	Weather resistant, durable
Electrical Assembly Sealing	Electrical enclosures, control panels	Protection from dust & moisture	Non-corrosive, electronics-safe
Construction Joints	Concrete joints, ceramic joints, gaps	Joint sealing & movement absorption	High elasticity, paintable
Automotive & Mechanical Sealing	Vehicle components, mechanical housings	Vibration & fluid resistance	Strong adhesion, flexible cure
General Purpose Sealing	Metal, wood, glass & composite joints	Long-term sealing	Wide substrate compatibility

Surface Preparation

Ensure all surfaces are clean, dry, and free from dust, grease, oil, rust, release agents, and other contaminants.
Clean surfaces using a suitable Fasto cleaner for best adhesion and performance.

Application Method

Apply Fasto S890 using a manual or pneumatic dispensing gun.
Assemble the parts immediately after application to avoid premature skin formation.
Tool the sealant before skin-over time to achieve a smooth and uniform joint.
Remove excess sealant if required.
Use masking tape for clean joint lines and remove it immediately after tooling and before skin formation.

Curing Information

Skin-over time: approx. 15–25 minutes
Tack-free time: approx. 25–35 minutes
Full cure: 24 hours (at ambient conditions)
(Curing time may vary depending on temperature, humidity, and joint thickness.)

Joint & Sealing Guidelines

Suitable for sealing static and low-movement joints
Ideal for metal, ceramic, concrete, wood, and composite joints
For wider joints, ensure sufficient sealant depth for flexibility
Avoid application in pure oxygen or oxygen-rich environments

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