Adheseal Hi-Flex 60 MS polymer Adhesive

For high-movement joint sealing and structural component bonding across diverse thermal expansion coefficients, Hi-Flex 60 MS polymer Adhesive is a high modulus hybrid elastomer that provides non-staining, primerless adhesion on most common construction substrates. Free from isocyanates and solvents, this low-odour formula cures via atmospheric moisture to form a permanently elastic, dust-proof seal suitable for internal and external applications.

How it works

Hi-Flex 60 MS polymer Adhesive relies on a neutral-cure hybrid polymer chemistry that reacts with air and substrate humidity to form a resilient seam. Its high modulus elastomer formulation prevents bleeding and staining on sensitive building materials while accommodating joints with movement up to ±25%. The cured adhesive is highly resistant to UV and weathering, and it can be painted over with acrylic, oil, and rubber-based paints. Non-corrosive and non-toxic, it maintains its physical properties across a service temperature window of -40°C to 100°C.

Numbers that matter

• ±25% movement capability (ASTM C719): High joint elasticity to accommodate structural expansion and contraction without cohesive or adhesive failure.
• 55 Shore A hardness (ASTM D2240): High puncture and wear resistance, making the cured sealant highly resilient against mechanical damage.
• 0.83 MPa tensile break (ASTM D412): High tensile strength to ensure secure bonding of structural panels and heavy building components.
• 3mm per 24 hours cure rate (at 23°C & 50% RH): Deep-cure progression from the exposed surface inwards under typical atmospheric conditions.
• 1.5 g/L VOC: Minimal chemical emissions, meeting green building environmental standards.

Where to use it

This adhesive and sealant is suitable for structural bonding and joint sealing across the following substrates and applications:

• Substrates: Masonry, fibre cement board, brick, XPS foam core reinforced sandwich panels, timber, plasterboard, metals (excluding lead and copper), plastics, stone (requires pre-use stain testing), painted surfaces, rubber, fibreglass, porcelain, aluminium, and powder-coated surfaces.
• Applications: Bonding XPS sandwich panels, acoustic ceiling tiles, seam sealing, bolted lap joints, prefabricated building panels, aluminium fabrication, display signs, and marine or automotive assembly.

Limitations

• Do not use for long-term water immersion, aquariums, or internal swimming pool applications where high chlorine exposure occurs.
• Do not use in totally confined spaces; the product requires atmospheric humidity to cure.
• Do not use for structural glazing (use N-80 or N-60 glazing silicone instead) or for adhering mirrors (use Hi-Power or MS609 instead).
• Do not use on bituminous, natural rubber, or EPDM surfaces, or alongside compounds that leach oils, plasticisers, or solvents.
• Sealant may discolour copper, brass, and titanium-zinc. For marble, granite, and other natural stones, S100 is recommended following a stain test.
• Do not expose the uncured sealant to cleaning agents, solvents, or alcohol during the curing process, as this may discolour or affect the material.
• Avoid application when moisture vapour transmission is emanating from the substrate, as this may cause gas bubbles to entrap and form in the sealant.

Installation and priming

All substrates must be structurally sound, dry, clean, and free of dust, oils, grease, curing compounds, surface water, and dampness. Concrete must be cured for at least 28 days to prevent adhesion failure. Impervious substrates must be pre-cleaned using the two-wipe process with a clean cloth and a solvent such as Xylene.

While the product achieves primerless adhesion on many surfaces, specific priming is required for high-stress joints, extreme weather exposure, or high-performance architectural applications:

• Non-porous substrates: For aluminium, stainless steel, PVC, galvanized steel, powder-coated metals, or glazed tiles, slightly roughen the joint face with a fine abrasive pad. Clean and pre-treat using Adheseal 50A surface prep. Allow a minimum of 30 minutes and a maximum of 2 hours before applying the sealant.
• Porous substrates: For concrete, aerated concrete, cement-based renders, mortars, and bricks, prime using Everflex Supaprime applied by brush. Allow 30 to 120 minutes drying time before application. Avoid excessive application that leads to primer puddling.

Applying as a sealant: Cut the nozzle at a 45-degree angle to the joint width. Run a continuous bead by pushing the sealant ahead of the nozzle to ensure full wet-out on both joint walls. Tool with a moistened spatula within the 10-minute skin window.

Applying as an adhesive: Cut a 90-degree V-notch into the nozzle (with the wedge opening twice as high as its width) to dispense a continuous, standing triangular bead. Press the two components together, compressing the adhesive bead to a thickness of no less than 2mm to ensure complete surface contact.

Joint design parameters

Where possible, design joints to a 2:1 width-to-depth ratio. Internal joints require a minimum width and depth of 5mm. External joints require a minimum width of 12mm. For joints deeper than 10mm, install an open-cell backer rod (compressed 25% larger than the joint width) or use a polyethylene bond-breaker tape to prevent three-sided adhesion failure.

• Joint width 5–10mm: Depth must equal width (minimum 5mm deep).
• Joint width 10mm: Depth must be 5–8mm.
• Joint width 15mm: Depth must be 7–10mm.
• Joint width 20mm: Depth must be 10mm.
• Joint width 25mm: Depth must be 12mm.