Loctite 438 Instant Adhesive 20g

Loctite 438 Prism Instant Adhesive 20g is a rubber-toughened, black instant adhesive engineered for maximum efficacy in high-impact bonding. This industrial-grade adhesive permanently bonds parts together, preventing costly component failures caused by shock, vibration, thermal cycling, or physical stress. Whether you are securing small to medium-size parts or specialized assemblies, this premium instant adhesive provides a robust, resilient seal on all substrates—including porous, acidic, and traditionally difficult materials.

Why Choose Loctite 438?

• Toughened & Impact Resistant: Formulated with a rubber modifier to absorb shocks, resist impacts, and offer superior peel strength compared to standard instant glues.
• Outstanding Material Compatibility: Provides rapid bonding across a wide range of materials, including plastics, rubbers, elastomers, and metals.
• Porous and Acidic Surface Optimization: Exhibits excellent adhesion on difficult substrates like wood, paper, leather, fabric, and acidic surfaces where other cyanoacrylates might fail.
• High Humidity & Environment Resistance: Engineered to maintain robust bond strength and flexibility even in damp or humid environments.
• Fast Fixturing: Achieves initial fixture strength in just 10 to 20 seconds, streamlining assembly lines and reducing clamp times.

Technical Specifications

• Product Type: Ethyl-based Instant Adhesive (Cyanoacrylate)
• Strength: High / Toughened
• Color: Black
• Container Size: 20g
• Key Specifications: Viscosity of 200 mPa.s (cP), Shear Strength (Grit Blasted Steel) of 2800 psi, and certified under Henkel LMS (November-01, 2005).

Simple Application Instructions

1. Clean: For optimal results, ensure all bond surfaces are clean, dry, and free from grease. Excess adhesive from previous applications can be dissolved with Loctite cleanup solvents, nitromethane, or acetone.
2. Apply: Apply a small amount of the adhesive to one surface. This product performs best in thin bond gaps (0.05 mm); over-application can delay curing.
3. Assemble: Bring the parts together quickly and press firmly. The formula will begin curing very quickly when confined as a thin film between two closely fitting surfaces, driven by atmospheric humidity. Full functional strength develops rapidly, with complete chemical resistance achieving full cure over 24 hours.

Frequently Asked Questions (FAQ)

What is Loctite 438 used for?

Loctite 438 is a rubber-toughened instant adhesive designed for structural, flexible, and high-impact bonding applications. It is specifically formulated to prevent component separation or bond failure due to mechanical shock, vibration, or environmental moisture.

Can Loctite 438 be disassembled?

Because Loctite 438 creates a permanent, high-strength bond, physical disassembly can be difficult without damaging the substrates. However, cured excess adhesive or bonded parts can be dissolved or weakened using nitromethane, acetone, or dedicated Loctite cleanup solvents.

Does Loctite 438 work on porous or acidic surfaces?

Yes. Unlike many standard super glues, Loctite 438 is explicitly engineered to perform exceptionally well on porous, absorbent, and acidic materials. It effortlessly bonds wood, paper, leather, and fabric alongside metals, plastics, and rubbers.

Is Loctite 438 safe for all systems?

Loctite 438 is solvent-free and safe for general industrial and workshop use. However, it is not recommended for use in pure oxygen or oxygen-rich systems, and should never be selected as a sealant for chlorine or other strong oxidizing materials. Always consult the Safety Data Sheet (SDS) for detailed safe handling practices.