Loctite Prism 420 Clear Ultra-Low_Viscosity Wicking (2cP Water-Like) Instant CA Adhesive-General Purpose (40640)

Product Name

Loctite Prism 420 Clear Ultra-Low Viscosity Wicking (2cP Water-Like) Instant CA Adhesive-General Purpose (40640)Also known as Loctite 420 Super Bonder Instant Adhesive.

Brief Description

Loctite 420 is a one-part, clear, ultra-low viscosity (water-like, 2cP) ethyl cyanoacrylate instant adhesive designed for general-purpose bonding. It cures rapidly upon exposure to atmospheric moisture, making it ideal for assembling close-fitting parts where its wicking capability allows it to penetrate into pre-assembled components.

Popular Applications & Uses

- Bonding of close-fitting parts where capillary action is required to fill small gaps.- Assembly of a wide range of materials including metals, plastics, and elastomers.- Rapid bonding applications in manufacturing and repair.- Can be used for bonding difficult-to-bond plastics (e.g., PP, PE, PTFE) when used in conjunction with a suitable primer like LOCTITE® SF 770.

Industries that Commonly Use It

- Aerospace/Defense- Automotive Service/Repair- Electrical Services or Products- Engineering Services- Fabrication- General Manufacturing- Government & Military (due to MIL-A-46050C compliance)- LED/Electronics- Medical Device/ Prosthetics- Metal Fabrication- Plastic Fabrication- Transportation/ Specialty Vehicle

Special and Unique Features

- Ultra-low viscosity (2cP, water-like) for excellent wicking and penetration into tight spaces.- Capillary action allows bonding of pre-assembled, close-fitting parts.- Fast fixture time, typically 5-20 seconds.- General purpose formulation suitable for a broad range of substrates.- Complies with Military Specification Mil-A-46050C Type II, Class I and Commercial Item Description A-A-3097.- Solvent-free.

Key Properties

- **Technology:** Cyanoacrylate- **Chemical Type:** Ethyl Cyanoacrylate- **Appearance (uncured):** Transparent, colorless to straw colored liquid- **Viscosity:** Very low, 1 to 5 cP (mPa·s) at 25°C- **Cure Method:** Humidity/Moisture cure- **Fixture Time:** 5 - 20 seconds (on various substrates)- **Full Cure Time:** 24 hours for full chemical/solvent resistance- **Gap Fill:** 0.05 mm (optimal), up to 0.15 mm- **Service Temperature Range:** -40°C to +120°C (typical for CAs, softening point 165°C)- **Tensile Strength:** 725 to 3,625 psi- **Dielectric Strength:** 25 kV/mm

Surface Compatibility

- **Metals:** Mild Steel, Aluminum, Zinc dichromate- **Rubbers:** Neoprene, Nitrile (Buna N)- **Plastics:** ABS, PVC, Polycarbonate, Phenolic. Can bond difficult-to-bond plastics like PP, PE, PTFE with a primer.

Known backups / known substitutes

- Infinity Bond RP 5 (Viscosity 5 cps)- Other general-purpose, low-viscosity ethyl cyanoacrylates from brands like Lockfast and Procure.- Loctite offers a range of other cyanoacrylates with varying viscosities and properties (e.g., Loctite 401, 406, 495, 414, 416, 422, 424).

Comparison Note

Loctite 420 stands out due to its extremely low viscosity and wicking capability, making it uniquely suited for applications requiring adhesive penetration into already assembled, close-fitting parts. While many instant adhesives offer fast cure times and broad substrate compatibility, the 420's water-like consistency is its defining feature, differentiating it from higher viscosity or gel-type cyanoacrylates. Its compliance with military specifications also highlights its reliability for demanding industrial and governmental applications.