When you need to bond timber, boards, and metals structurally, quickly, and with D4 waterproof integrity, reaching for the right solution is critical. Adheseal Unobond FC is a single-pack, polyurethane adhesive formulated for demanding construction and marine applications. Packaged in a 6kg drum, it allows for efficient, high-coverage application, securing large areas with superior, invisible bonds.

Why this product exists

Formulated to eliminate production inefficiencies and unreliable bonds in large-scale applications, Adheseal Unobond FC delivers superior, fast-setting, D4 waterproof, structural bonds across diverse materials. Its single-pack, solvent-free polyurethane chemistry cures rapidly with ambient moisture, providing robust adhesion without mixing. The 6kg drum format ensures efficient coverage for production-scale bonding, preventing project delays and rework.

The numbers that matter

• D4 Water Resistance: This isn't just water-resistant; it's classified D4. That means it withstands a 72-hour boiling water test, making it suitable for exterior and marine environments where persistent moisture exposure is a factor.
• 5 N/mm² Tensile Strength: Unobond FC is a structural adhesive, not just a grab glue. It forms bonds that are often stronger than the substrates themselves, designed to hold under significant load.
• 15-Minute Working Time, 60-Minute Pressing Time: With a 15-minute working time and 10-minute skin time, you have the window needed to align components precisely. Then, press for just 60 minutes at 0.6 N/mm² to establish initial structural integrity, accelerating project timelines.
• 0.1-0.25mm Bond Line: Designed for tight-fitting joints, ideally between 0.1-0.25mm, with a maximum of 0.5mm. This ensures optimal strength and an invisible finish, expanding slightly to fill minor irregularities for a solid bond.

What it's like to use

Prepare surfaces to be structurally sound, dry, and clean, ensuring at least one surface contains moisture for optimal cure. For impervious metals, wipe clean with Xylene, then sand lightly to improve adhesion. Apply Unobond FC over one surface, spreading it evenly within the 15-minute working time. If conditions are dry or bonding non-porous materials, a light mist of water on the second surface aids curing. Bring components together immediately, clamping tightly for a minimum of 60 minutes. Maintain 50 PSI for softwoods or 150 PSI for hardwoods to ensure proper adhesive spread. Clean wet spills and tools with Xylene. Cured adhesive requires mechanical removal.

Where this product excels

• Marine and Exterior Woodwork: For wooden boat building and external timber applications, its D4 water resistance and resilience ensure long-term durability against moisture.
• Furniture, Cabinets, and Joinery: Integrate with clamping cycles in manufacturing furniture, cabinets, and joinery components. The defined working and pressing times support efficient production with fewer rejects.
• Flooring Systems: Apply a bead into the groove of each panel in tongue-and-groove flooring. The slight expansion fills voids, helping prevent movement and reducing squeaks for a solid, professional finish.
• General Construction and Mixed Materials: Bond timber, boards, concrete, and metals in general construction and mixed-material assemblies. Its versatility reduces the need for multiple adhesive systems across diverse substrates.
• Display Signs and Fabrication: Achieve reliable, structural bonds for display signs and other fabricated assemblies where various materials need to be joined securely.

Choose this when

• When you need structural, D4 waterproof bonds for long-term durability in wet or external conditions.
• When undertaking bulk applications requiring efficient, high-coverage bonding from a 6kg drum format.
• When working with materials like timber, boards, concrete, and metals where a single, versatile adhesive is preferred.
• When manufacturing furniture, cabinets, or marine components where fast setting and strong, invisible bond lines are critical.
• When installing flooring systems and aiming to reduce squeaks and improve panel stability.

Don't use this when

• Not for: Use as a gap filler, as this reduces the strength of the adhesive. It is designed for tight-fitting, structural bonds.
• Not for: Totally confined spaces, as the adhesive requires atmospheric humidity to cure properly.
• Not for: Adhering mirrors; consider Adheseal High Power 609, testing first for compatibility.
• Not for: Structural glazing; for these applications, Adheseal N-80 or N-60 glazing silicones are recommended.

Unobond FC vs. Adheseal Unobond Polyurethane Adhesive (Cartridge)

Adheseal Unobond FC is a structural adhesive designed for tight-fitting bond lines (0.1-0.25mm ideal, max 0.5mm) and efficient, high-coverage application from its 6kg drum. It is not designed for filling voids where bond strength would be compromised. For smaller, precise applications or jobs requiring a non-drip gel consistency, consider Adheseal Unobond Polyurethane Adhesive, which offers the same D4 waterproof, structural bonding for spot applications.