Megapoxy Megabond

For bonding natural stones and tiles to masonry substrates where staining or moisture sensitivity is a risk, Megapoxy Megabond provides a high-strength, structural epoxy connection. This VOC-free, 100% solids adhesive cures to an off-white finish that will not stain light-coloured marbles, making it suitable for high-exposure miter joints, stone repair, and structural bonding on both interior and exterior installations.

High-strength structural adhesion

Megabond is formulated for high shock and chemical resistance, curing to physical properties that exceed the strength of standard concrete. Its creamy, non-sagging texture is designed to spread easily with a notched trowel, allowing installers to set large-format tiles, bond compressed cement sheet, or secure precast concrete articles without slippage. The formula can also be tinted with Megapoxy coloured pigment pastes to match specific stone selections or to blend repairs when patching chipped stone edges and filling voids.

Numbers that matter

• 60 MPa compressive strength (ASTM D695-23): Delivers structural crushing resistance far exceeding standard concrete.
• >3 MPa concrete bond strength (ASTM D4541): Ensures structural adhesion that consistently exceeds the cohesive strength of concrete substrates.
• 10 MPa tensile bond strength on steel (ASTM D897-08): Provides high-tenacity bonding for heavy metal-to-metal or metal-to-concrete assemblies.
• 45-minute work time (at 25°C): Provides a practical window to align large stones, adjust complex miter joints, or butter vertical tile surfaces.
• 24-hour cure time (at 25°C): Reaches minimum service cure within 24 hours at standard temperatures (extends to 48 hours at 15°C, or accelerates to 12 hours at 35°C).

Where to use it

This adhesive bonds to stone, tile, cement sheet, cement render, plasterboard, timber, concrete, and metal. Typical applications include:

• Bonding precast concrete articles and insitu formed concrete.
• Fixing natural stones, water-sensitive stones, and composite stone panels.
• Securing miter joints, bricks, and ceramics.
• Filling and repairing stone holes, voids, concrete floors, stairs, and columns.
• Bonding compressed cement sheet and fibreglass articles.

Limitations

• Do not bond directly to painted, coated, or galvanised surfaces; all coatings must be removed to bare substrate before application to prevent inferior bond strength.
• Do not rely on wire brushing for metal preparation; it is not satisfactory and provides minimal adhesion.
• Do not apply at temperatures below the minimum application threshold of 10°C.
• Do not alter the 1:1 mixing ratio; inaccuracies or poor mixing will lower the cured physical properties, prevent proper curing, and cause discolouration over time.

Surface preparation and application

For successful adhesion, substrates must be properly prepared before mixing the 1:1 ratio:

• Concrete: Must be free from grease and oil. Remove surface laitance via mechanical abrasion (scabbling, grit blasting, or grinding). If acid etching is required, apply a 1:1 mix of hydrochloric acid and water at 0.5 litres per square metre, allow to react for 10 minutes, scrub with a stiff broom, wash thoroughly, and allow to dry for 24 hours until surface dry.
• Metal: Grit blast to AS CK 9.4 - 1964 Class 3 finish, or mechanically abrade to bright metal and degrease with an industrial degreaser.
• Coated surfaces: Remove paint from concrete using flame-cleaning or a scutching tool, followed by diamond grinding or scabbling. Remove paint or galvanising from metal using a quality paint stripper followed by grit blasting or grinding.
• Cleanup: Clean all mixing tools and implements immediately after use with Megapoxy Thinners.