Megapoxy HX

For structural concrete crack repair, low-pressure injection, and masonry sealing, Megapoxy HX is a 100% solids, solvent-free epoxy liquid with an extra-low mixed viscosity of 200cps at 25°C. This thin profile enables deep capillary penetration into tight fissures, pores, and micro-cracks across concrete, masonry, timber, fibreglass, and metal substrates.

What it does

Megapoxy HX functions as a deep-penetrating hydrophilic liquid resin that cures to high compressive and tensile strengths. By displacing air through capillary action or low-pressure injection, it forms a permanent bond within the substrate that is mechanically stronger than concrete itself. Its 100% solids formulation ensures zero shrinkage during cure, preserving the structural integrity of repairs in floors, castings, and laminating applications. It is also formulated to resist a wide range of industrial chemicals, making it suitable for long-term surface hardening and sealing of porous masonry.

Numbers that matter

• Mixed Viscosity of 200cps (at 25°C): Provides a water-like consistency to penetrate fine capillaries and deep structural cracks under low pressure.
• 140MPa Compressive Strength (ASTM C579): Delivers structural load-bearing capacity that far exceeds standard concrete strengths.
• >3MPa Concrete Bond Strength (ASTM D4541): Ensures cohesive failure occurs within the concrete substrate rather than at the epoxy bond line.
• 60-Minute Work Time (at 25°C): Provides an extended application window to set up injection lines, pump, or vacuum-bag laminates before curing begins.
• 24-Hour Minimum Cure (at 25°C): Resolves to full handling strength in 24 hours, though cure times vary with temperature (12 hours at 35°C; 48 hours at 15°C).

Where to use it

Megapoxy HX is formulated for trade applications requiring high-penetration liquid resins, including:

• Concrete Crack Repair: Gravity penetration or low-pressure and pressure-injection methods to seal structural fissures.
• Substrate Hardening and Sealing: Impregnation of porous masonry and timber surfaces to increase wear and chemical resistance.
• Laminating and Casting: Wetting out fibreglass or vacuum-bagging composites where a low-viscosity clear resin is required.

Limitations

• Do not apply Megapoxy HX at temperatures below the minimum application limit of 10°C.
• Avoid bonding directly to coated surfaces. All paint, coatings, and galvanising must be completely removed to prevent a reduction in bond strength.
• Do not rely on wire brushing for metal surface preparation; it provides minimal adhesion only. Use grit blasting or mechanical grinding to clean, bright metal.
• Exact 3:1 mixing ratios by volume are critical. Inaccurate ratios or incomplete mixing will lower cured physical properties, prevent satisfactory curing, and cause discolouration over time.

Installation and crack treatment

For optimal bond strength, all substrates must be dry, clean, and free from surface laitance, grease, and oil.

Concrete Preparation: Remove surface laitance via mechanical abrasion (scabbling, grit blasting, or grinding). If mechanical preparation is not possible, acid etch using a 1:1 mix of concentrated hydrochloric acid and water at a rate of 0.5 litres per square metre. Let react for 10 minutes, scrub with a stiff broom, rinse thoroughly, and allow to dry for 24 hours.

Metal Preparation: Grit blast to AS 1627.2.2002 or mechanically grind to a bright metal finish, then degrease with an industrial-grade degreaser.

Capillary Action Crack Repair: Clean the crack by applying Methylated Spirits or Acetone, then brush-coat the mixed Megapoxy HX directly over the crack. The resin will draw deep into the fissure as the solvent evaporates.

Low-Pressure Injection: Grind the concrete surrounding the crack. Bond crack injection balloons 300mm apart over the crack using Megapoxy PM paste, sealing the bases and 50mm on either side of the crack. Once the PM paste cures, pump mixed Megapoxy HX through the balloon ports using a crack injection gun until the balloons inflate to approximately 20mm and stay filled. Knock off ports and grind smooth once cured.

Clean-up: Clean all mixing implements and application tools immediately after use with Megapoxy Thinners.