When structural concrete and steel repairs demand reliability in the most challenging conditions, Megapoxy H delivers. This low-viscosity, hydrophilic epoxy resin handles critical bonding, crack repair, and high-strength mortar applications, even in potable water or submerged environments. It ensures durability and compliance where other solutions fall short.
Megapoxy H is engineered as a low viscosity, 100% solids, solvent-free, hydrophilic epoxy resin. It provides robust structural repair, bonding, and high-strength mortar solutions. This formulation addresses the need for materials that maintain integrity in critical environments, including contact with drinking water and exposure to aggressive chemicals like hydrogen sulphide. It establishes strong, permanent bonds between new and old concrete, repairs cracks, and is suitable for underwater and splashzone applications.
Megapoxy H requires precise mixing at a ratio of 3 parts A to 1 part B by volume. Thorough mixing for a minimum of three minutes is critical for optimal performance. Once mixed, it offers a 30-minute work time at 25°C, allowing sufficient time for placement, pouring, or injection. Minimum application temperature is 10°C.
Surface preparation is key for maximum adhesion. Concrete surfaces must be clean, free from grease, oil, and laitance. Mechanical abrasion (scabbling, grit blasting, or grinding) is preferred. If not possible, acid etching can be used, followed by thorough washing and 24 hours of drying. Metal surfaces require grit blasting to AS 1627.2.2002 or mechanical abrasion to a clean, bright finish, followed by degreasing. All existing coatings should be removed to ensure superior bond strength. For cleaning tools and implements, use Megapoxy Thinners.
Megapoxy H frequently serves as an initial and critical step in comprehensive concrete repair systems. It is applied early in the sequence, either as a primer or for crack injection, establishing a strong foundation before subsequent layers. For example, in concrete repair, it acts as a primary bonding agent for new-to-old concrete or as the injection resin for structural crack repairs.
This product is often specified alongside companion products like coloured epoxy floor epoxy base coats in plant rooms, where it primes the concrete for trafficable epoxy finishes. For more extensive concrete patching, it can be paired with epoxy concrete patch rapid concrete repair paste or epoxy surface sealant joint band adhesive for detailing and capping cracks.
Yes, Megapoxy H complies with AS/NZS 4020:2018 for products in contact with drinking water. This certification ensures it is suitable for repairs and bonding in potable water infrastructure.
No, for horizontal steel anchoring, Megapoxy HT is the specified product. Megapoxy H is suitable for vertical steel anchoring where it can be poured from one side to allow air escape.
Megapoxy H delivers high mechanical strengths, including a bond strength to concrete greater than 3 MPa. When used in epoxy mortars, compressive strengths can range from 70-80 MPa, depending on the aggregate blend.
The mixing ratio of 3 parts A to 1 part B by volume is critical for Megapoxy H. Incorrect ratios or insufficient mixing will reduce the cured system's physical properties and may prevent proper curing or cause discolouration.
| Application | Key benefit | Primary trades |
|---|---|---|
| Potable water infrastructure repair | Certified to AS/NZS 4020:2018 for contact with drinking water, preventing contamination. | Civil engineers, utilities contractors |
| Wet-to-dry concrete bonding | Hydrophilic nature allows for strong, permanent bonds even on damp substrates. | Concrete repair specialists, marine contractors |
| Concrete crack repair (injection) | Low viscosity allows deep penetration into cracks, restoring structural integrity with high compressive strength (92-120 MPa). | Concrete repair specialists |
| Steel anchoring into concrete | High tensile bond strength to steel (18 MPa) and concrete, securing anchor bolts and reinforcing bars. | Structural engineers, concreters |
| Underwater and splashzone repairs | Maintains excellent static and dynamic mechanical properties in demanding submerged environments. | Marine contractors, port authorities |
| Epoxy mortars for floor repairs/grouting | Forms high-strength epoxy mortars (70-80 MPa compressive strength) for durable floor and large pocket grouting. | Flooring contractors, industrial maintenance |
| Sewage treatment plant repairs | Resistant to hydrogen sulphide, ensuring longevity in corrosive wastewater environments. | Wastewater engineers, utilities contractors |
Ensure all substrates are prepared according to the Adhesion Profile. Surfaces must be sound, clean, and free of all contaminants, laitance, or previous coatings to ensure a permanent, structural bond. Mechanical abrasion is the preferred method.
This is the most critical step for achieving the product's specified strength. Inaccurate mixing will lead to cure failure.
Measure exactly 3 Parts A to 1 Part B by volume. Use separate, clean, graduated mixing containers to ensure accuracy.
Combine the two parts into a clean mixing vessel. Mix thoroughly with a flat paddle or mechanical mixer at low speed. Scrape the sides and bottom of the container multiple times to ensure no unblended material remains. Mix until 100% uniform in colour.
For bonding new concrete to old, apply the mixed Megapoxy H to the prepared old concrete surface using a brush, roller, or airless spray.
Apply at a rate of 1 to 1.5 litres per square metre. Ensure an even, full coat.
To create a high-strength epoxy mortar, you must prime the surface first.
Apply a brush coat of pre-mixed, neat Megapoxy H to the prepared concrete surface. Do not let this coat cure.
While the primer coat is still wet, apply your mixed epoxy mortar (e.g., Megapoxy H + 12 parts Silica 50N) and trowel to the desired finish.
Signal Word: Danger
Wear safety shoes, nitrile gloves, and safety glasses. Ensure all PPE is suitable for the nature of the work and identified hazards. Contaminated work clothing must not leave the workplace. Always wash hands thoroughly after handling and before eating, drinking, or smoking.
Natural ventilation should be adequate under normal use conditions. Avoid breathing dust, fume, gas, mist, vapours, or spray.
Store in a cool, dry, well-ventilated place, out of direct sunlight, and away from foodstuffs and incompatible materials. Keep containers upright and closed. Part B must be stored locked up. Dispose of material and containers in accordance with local regulations; recycling is preferred where possible.
Proper surface preparation is fundamental to Megapoxy H achieving its documented bond and mechanical performance, particularly for critical applications.
Surface prep: Ensure concrete is clean and free from grease and oil. Use an industrial heavy-duty degreaser if required. Remove surface laitance by mechanical abrasion such as scabbling, grit blasting, or grinding. If mechanical methods are not feasible, acid etching can be used: apply a 1:1 mixture of concentrated hydrochloric acid and water at 0.5 litres per square metre, allow to react for 10 minutes, then wash thoroughly and scrub. Allow 24 hours to dry. Concrete must be surface dry for maximum adhesion.
Primer: Not required for bonding new to old concrete or in mortar applications, as Megapoxy H itself acts as the primer coat.
Surface prep: Grit blast to AS 1627.2.2002. If grit blasting is not possible, mechanically abrade the surface to achieve a clean, bright metal finish. Degrease the surface with an industrial-grade degreaser after abrasion. Wire brushing alone provides minimal adhesion and is not sufficient.
Primer: Not required.
Surface prep: All existing coatings must be removed to ensure optimal bond strength. Bonding to coated surfaces will result in inferior performance. For concrete, flame-clean or mechanically treat with a scutching tool, then diamond grind or scabble. For metals, use a quality paint stripper, followed by grit blasting or grinding to a bright metal finish, ensuring all paint and galvanising are removed.
Primer: Not required after complete coating removal and proper substrate preparation.
| Property | Value |
|---|---|
| Mixing Ratio By Volume Part A To Part B | 3:1 |
| Work Time At 25C | 30 minutes |
| Minimum Cure Time At 15C | 48 hours |
| Minimum Cure Time At 25C | 24 hours |
| Minimum Cure Time At 35C | 12 hours |
| Thin Film Cure At 25C | 5-6 hours |
| Minimum Application Temperature | 10°C |
| Viscosity Part A At 25C | 1300 - 1900 cps |
| Viscosity Part B At 25C | 75 - 90 cps |
| Mixed Viscosity At 25C | 800 cps |
| Density Part A At 25C | 1.12 - 1.14 g/cm³ |
| Density Part B At 25C | 0.97 – 0.99 g/cm³ |
| Mixed Density At 25C | 1.09 g/cm³ |
| Colour Part A | Clear or N35 Grey |
| Colour Part B | Clear |
| Colour Mixed | Clear or N35 Grey |
| Yield Compressive Strength ASTM C579 | 92 MPa |
| Ultimate Compressive Strength ASTM C579 | 120 MPa |
| Bond Strength Concrete ASTM D4541 | >3 MPa |
| Tensile Bond Strength Steel ASTM D897 | 18 MPa |
| Modulus Of Elasticity ASTM C579 | 1.7 GPa |
| Flexural Strength ASTM D790 | 59 MPa |
| Tensile Strength ASTM D638 | 57 MPa |
| Tensile Lap Shear Strength ASTM D1002 | 7 MPa (steel to steel) |
| Hardness Shore D ASTM D2240-00 | 75 minimum |
| Dielectric Strength | 13.6 kV/mm |
| Surface Resistivity ASTM D257 | 10¹² Ohm |
| Volume Resistivity | 2.2 x 10¹¹ Ohm.cm |
| VOC | 2 g/l |
| Water Vapour Transmission ASTM E96/E96M | 0.095 g/hr m² |
| Water Absorption ASTM D570 | 0.184 % increase in weight |
Here are some common examples on where Megapoxy H used by our customers.
