K-FLEX K-420 Contact Adhesive for Pipe Insulation 250ml

K-FLEX K-420 is the correct contact adhesive for bonding K-FLEX pipe insulation on bends, tees, fittings and any joint where self-seal tape alone is not sufficient — completing the vapour barrier on every complex connection.

• ✔ Designed specifically for K-FLEX elastomeric foam insulation
• ✔ Essential for bends, tees and complex fittings
• ✔ Completes the vapour barrier where tape cannot reach

When Do You Need K-420 Adhesive?

Self-seal insulation and ST tape handle straight runs and simple joints — but bends, tees, reducers and complex fittings require a contact adhesive to achieve a continuous, airtight bond. K-420 is the manufacturer-recommended adhesive for all K-FLEX elastomeric foam insulation, ensuring full compatibility and a lasting seal on every part of the system.

On a typical AC installation, K-420 is used at every bend and fitting — a 250ml tin is sufficient for most single-unit domestic installations.

Where This Is Used

• Bonding insulation on pipe bends and elbows
• Sealing tee junctions and reducers
• Closing longitudinal seams on non-self-seal K-FLEX insulation
• Bonding insulation to fittings and valves
• Any joint requiring a permanent, airtight elastomeric bond

Key Features

• Contact adhesive — apply to both surfaces, allow to tack, then press together
• Specifically formulated for elastomeric foam insulation
• Compatible with all K-FLEX ST, SK and standard tube insulation
• Fast-tack formula for efficient on-site use
• 250ml tin — sufficient for a typical domestic AC installation
• Solvent-based — use in well-ventilated areas

Technical Specifications

How to Use

• Clean both surfaces to be bonded
• Apply K-420 to both surfaces using a brush or spreader
• Allow to become touch-dry (approximately 5–10 minutes)
• Press surfaces firmly together — bond is immediate on contact
• Use in a well-ventilated area

Complete Your Insulation System

• K-FLEX ST Self-Seal Pipe Insulation — the primary insulation K-420 is designed to bond
• K-FLEX ST Insulation Tape — for sealing straight joints and cut ends
• AC Copper Pipe — refrigerant-grade pipework for AC systems
• Fittings & Connectors — refrigeration fittings requiring insulation finishing

Most engineers use K-420 alongside K-FLEX ST Self-Seal insulation and K-FLEX ST tape to complete a full, professional insulation system.

Also known as: insulation adhesive, pipe lagging glue, elastomeric foam adhesive, K-FLEX glue, insulation contact adhesive.

Order K-FLEX K-420 contact adhesive today — available from UK stock with fast trade delivery.