What is SIKA® LOCK-2 GEL EC and why choose it
SIKA® LOCK-2 GEL EC is a high-viscosity ethyl cyanoacrylate adhesive supplied as a clear gel. It is designed for strong, fast bonding of a wide variety of materials, including plastics, rubbers, metals, porous substrates and ceramics. Its thixotropic gel consistency allows application in vertical positions and joints with a certain gap without dripping or running, delivering reliable, high-strength bonds in demanding industrial environments.
Main features
- Chemical base: Ethyl cyanoacrylate.
- High viscosity gel: Clear thixotropic gel that stays in place, suitable for vertical surfaces and controlled bead application.
- Fast curing:
- Steel/steel: < 120 seconds.
- ABS/ABS: < 60 seconds.
- Rubber/rubber: < 45 seconds.
- Surface dry time: 45–180 seconds.
- Full cure: 24 hours.
- High mechanical strength: Approx. 20 N/mm² (ISO 6922).
- Service temperature range: From -50°C to 80°C.
- Gap-filling capability: Recommended bond line thickness up to 0.25 mm.
- Excellent adhesion on multiple substrates: Suitable for many plastics, rubbers, metals, porous materials and ceramics.
- Performance on porous substrates: Formulated to bond substrates with high porosity.
- Engineered quality: Developed in accordance with ISO 9001/14001 quality and environmental management standards.
- Chemical resistance: Very good resistance to oils and many solvents, including engine oil, leaded gasoline, ethanol, propanol and freon.
- Heat resistance:
- At 80°C, bonded joints retain more than 70% of the strength measured at 21°C.
- At 100°C, bond strength is approximately 50% of that at 21°C.
- After exposure to 80°C for 90 days, then cooled and tested at 21°C, bonds retain about 90% of their strength.
- Shelf life: 12 months in a dry location at 5–25°C.
- Packaging options: 20 g and 50 g bottles; bulk supply for application systems.
Technical specifications
- Chemical base: Ethyl cyanoacrylate.
- Appearance / colour: Clear gel.
- Density: Approx. 1.10 kg/l.
- Melting point: > 85°C.
- Recommended bond line thickness: 0.25 mm.
- Viscosity (Brookfield RTV, T-spindle C):
- At 2.5 rpm: 50,000–90,000 mPa·s.
- At 20 rpm: 7,000–20,000 mPa·s.
- Curing speed (at 21°C):
- Steel/steel: < 120 s.
- ABS/ABS: < 60 s.
- Rubber/rubber: < 45 s.
- Drying time: 45–180 s.
- Full cure time: 24 hours.
- Mechanical strength (ISO 6922): Approx. 20 N/mm².
- Service temperature range: -50°C to 80°C.
- Recommended storage conditions: Cool place, protected from sunlight; 5°C recommended for optimum stability.
- Shelf life: 12 months (in a dry place at 5–25°C).
- Chemical resistance: Excellent resistance to oils and solvents including engine oil, leaded gasoline, ethanol, propanol and freon. Not resistant to high humidity.
Applications and use cases
Recommended substrates
- Plastics (including ABS and various engineering plastics).
- Rubbers (various types).
- Metals.
- Ceramics.
- Porous substrates.
Typical application scenarios
- High-strength bonding: Situations requiring strong, durable joints between plastics, rubbers, metals or ceramics.
- Porous materials: Bonding of parts with high porosity where conventional liquid cyanoacrylates may penetrate excessively.
- Vertical and overhead joints: Assemblies where a non-drip, non-sag adhesive is needed, thanks to the thixotropic gel consistency.
Curing behaviour and substrate considerations
- The curing speed of cyanoacrylates depends on the substrate. Acidic surfaces such as paper or leather show longer curing times than many plastics or rubbers.
- Plastics with very low surface energy (e.g. polyethylene, polypropylene, PTFE) require the use of Sika® Lock-4077 PM Primer.
- Low humidity and low temperatures slow down the curing process. All performance tests are carried out at 21°C.
- Thin adhesive layers provide faster polymerisation and higher bond strength. Excessive adhesive layer thickness reduces curing speed and bond performance.
- Use of Sika® Lock-4011 AK cyanoacrylate activator can significantly increase curing speed (up to approximately 2 seconds with Sika® Lock adhesives), but may reduce bond strength by more than 30%. Preliminary tests are recommended.
Application method
Surface preparation
- Ensure that all substrates are clean, dry and free from oil and grease.
- Use Sika® Lock activators on porous surfaces when required.
- Certain plastics require pre-treatment with Sika® Lock-4077 PM Primer.
Adhesive application
- Apply a small, thin layer of SIKA® LOCK-2 GEL EC to one of the substrates.
- Bring the parts together and press firmly until the joint develops handling strength.
- Only a small quantity of cyanoacrylate should be used; excessive adhesive quantity leads to slower curing and lower final bond strength.
- For high-volume production, SIKA® LOCK-2 GEL EC can be dispensed using suitable application and distribution systems.
FAQ
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On which materials can SIKA® LOCK-2 GEL EC be used?
It is suitable for bonding many plastics (including ABS), rubbers, metals, porous substrates and ceramics. Plastics with very low surface energy such as polyethylene, polypropylene and PTFE require Sika® Lock-4077 PM Primer.
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How fast does SIKA® LOCK-2 GEL EC cure?
At 21°C, typical fixture times are less than 120 seconds for steel/steel, less than 60 seconds for ABS/ABS and less than 45 seconds for rubber/rubber. Full cure is reached in about 24 hours.
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What is the recommended bond line thickness?
The product is designed for bond lines up to approximately 0.25 mm. Thin layers provide faster curing and higher bond strength.
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Is SIKA® LOCK-2 GEL EC suitable for vertical applications?
Yes. Its thixotropic gel consistency prevents dripping and sagging, making it suitable for vertical surfaces and for bonding joints with a certain gap.
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How resistant is the adhesive to temperature?
It can be used from -50°C to 80°C. At 80°C the bond retains more than 70% of its strength at 21°C, and at 100°C about 50%.
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Does humidity affect the bond?
Yes. Cyanoacrylates require surface moisture to initiate curing, but they do not withstand high levels of humidity over time. High humidity can reduce performance.
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How should SIKA® LOCK-2 GEL EC be stored?
Store in a cool place away from direct sunlight. Storage at around 5°C is recommended for optimal stability. In a dry place at 5–25°C, the shelf life is 12 months.
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What packaging sizes are available?
It is supplied in 20 g and 50 g bottles, and in bulk for application systems.
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Can I speed up curing?
Yes. Sika® Lock-4011 AK cyanoacrylate activator can be used with Sika® Lock adhesives to significantly increase curing speed, potentially down to about 2 seconds, but it may reduce bond strength by more than 30%.
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Is additional documentation available?
Safety Data Sheets are available for further information.
Section 14 – Transport information
Consultar ficha técnica del fabricante.
Section 8 – Personal protective measures
Consultar ficha técnica del fabricante.
*Contenido generado por IA
