Fasto LB550 – LED Grade, non Corrosive, RTV Silicone Sealant & Adhesive

Fasto LB550 is a high-performance, non-corrosive, silicone-based, low-bloom RTV sealant and adhesive, specially formulated for applications where minimal smoke or blooming is critical during assembly. Its low bloom characteristics prevent fogging or residue deposition on glass and diffusers, making it ideal for LED lighting and electronic assemblies.

Fasto LB550 offers excellent electrical insulation, weather resistance, and high-temperature performance, ensuring long-term reliability in demanding environments.

Packaging:

Part A: 300ml

Part B: 2600ml

Key Features

Low Bloom/Low Smoke Formulation
Prevents haze, fogging, or residue on glass and plastic diffusers.
Non-Corrosive & Electronics Safe
Suitable for sensitive electronic and electrical components.
High Temperature Resistance
Performs reliably up to 150°C (continuous) and ~210°C (intermittent).
Excellent Electrical Insulation
Ideal for LED drivers, relays, and switches.
Thick Paste Consistency
Easy application from tubes or cartridges without dripping.
Good Weatherability
Suitable for long-term indoor and outdoor use.

Benefits

Ensures clean, haze-free LED light assemblies
Improves optical clarity and product aesthetics
Reduces rework and rejection due to blooming
Enhances durability of electronic and electrical assemblies
Ideal for high-precision manufacturing environments

Primary Application	Sub-Applications	Functional Purpose	Key Performance Advantage
LED Diffuser & Glass Bonding	LED diffusers, glass covers, light lenses	Secure bonding without surface contamination	Low bloom / low smoke, clean assembly finish
LED Lighting Assembly Sealing	LED housings, internal joints	Sealing & bonding during luminaire assembly	Good electrical insulation, weatherability
LED Driver Bonding & Fixing	LED drivers, power modules	Component fixation & vibration resistance	Stable adhesion, high temperature performance
Relay & Electrical Switch Assembly	Relays, electrical switches	Secure assembly of electrical components	Non-corrosive, electrically safe
Electronics & Electrical Device Assembly	Consumer electronics, electrical devices	Bonding & sealing sensitive parts	Low emission during curing, reliable insulation
Glass & Plastic Component Bonding	Glass-to-plastic, plastic-to-metal joints	Clean bonding of visible components	Avoids fogging or deposition on surfaces
Multi-Substrate Bonding & Sealing	Metals, glass, engineering plastics	Versatile adhesion across materials	Broad substrate compatibility

Surface Preparation

Clean all bonding surfaces thoroughly to remove dust, grease, oil, rust, scale, and contaminants.
Use a suitable Fasto cleaner if required.

Application Method

Apply Fasto LB550 evenly from a tube or cartridge between contact surfaces.
Use sufficient quantity only; excessive application should be avoided.
Assemble parts and perform tooling before skin-over time.
Remove excess material if required for a neat finish.

Application Conditions

Recommended application temperature: 5°C to 40°C
Optimum application range: 15°C to 25°C

Curing Information

Tack-free time: 5–10 minutes
Skin-over time: 20–30 minutes
Full cure: 24 hours
(Curing depends on humidity, temperature, and bead thickness)

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