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Unobond FC: A Product Overview
Unobond FC is a single-pack, liquid polyurethane adhesive engineered for broad-area structural bonding and high-output workflows. Its moisture-curing formulation delivers a D4-rated waterproof bond that stands up to demanding Australian conditions, from exterior fabrication to marine-adjacent builds. The liquid consistency spreads easily across wide panels and flooring substrates, helping installers achieve a uniform glue line that cures predictably under clamping pressure. A defined 10-minute skin time and reliable 24-hour full cure support fast, first-time-right installations across construction, joinery, and manufacturing environments. Low VOC, solvent-free chemistry reinforces safer work practices while delivering confidence on every joint.
Key Features of Unobond FC
- Liquid polyurethane adhesive: ideal for high-coverage applications such as flooring and large-format bonding.
- Structural-grade D4 waterproof bond: withstands 72-hour boiling-water exposure for long-term durability indoors and out.
- Moisture-curing formulation: bonds porous-to-porous and porous-to-non-porous substrates when at least one surface contains moisture.
- Slight expansion on cure: fills micro-voids to increase contact area and reduce the risk of weak bonding zones.
- 10-minute skinning time & 1-hour pressing time: supports efficient production cycles and accurate alignment before set.
- Service temperature -30°C to +100°C: reliable performance across harsh Australian climate conditions.
- Exceptional substrate compatibility: bonds timber, concrete, metals, FC sheeting, EPS foam, brick, plasterboard, particleboard, melamine and many plastics (testing recommended).
- High coverage efficiency: 7.5–10 m² per litre supports economical use in large-scale manufacturing and flooring work.
- Low VOC, solvent-free and non-corrosive: meets key environmental and substrate protection requirements.
The Unobond FC Advantage
- High spreadability reduces labour time and ensures predictable coverage during large-area bonding.
- Structural-grade reliability with D4 waterproof performance minimises rework, protecting both margins and reputation.
- Versatile bonding across metals, concretes, composites and timber simplifies inventory and improves workflow consistency.
- Liquid format penetrates irregular surfaces for maximum adhesion, reducing the risk of callbacks caused by poor contact.
- Safer handling profile thanks to low VOC and non-corrosive chemistry supports better onsite air quality and long-term durability.
Adheseal tips for using Unobond FC
Scenario: Using Unobond FC as a gap filler
Potential Outcome: Bond strength is reduced because structural performance requires compression and a controlled glue line.
Adheseal Best Practice: Keep joints close-fitting (0.1–0.25 mm) and clamp or fasten adequately. This ensures the adhesive cures as designed and supports long-term load performance.
Scenario: Bonding in fully sealed cavities
Potential Outcome: The adhesive may not cure due to a lack of atmospheric moisture, leaving the joint soft or uncured.
Adheseal Best Practice: Ensure at least one substrate has sufficient internal moisture, or lightly mist the opposite surface in dry or cool conditions. This activates cure and ensures predictable results.
Scenario: Insufficient surface cleaning on metals
Potential Outcome: Oils and residues can cause partial adhesion or delamination over time.
Adheseal Best Practice: Lightly abrade metal surfaces and use the two-wipe solvent cleaning method (e.g., xylene with fresh cloths). Clean surfaces prevent adhesion failures and ensure first-time-right bonding.
Applications in Practice: Trade Scenarios
For Flooring Installers (On-site Applicator): Large-area panel bonding
The Professional's Challenge
Achieving consistent glue coverage across large flooring areas while preventing future squeaks or movement requires an adhesive that spreads easily and cures reliably.
The Adheseal Solution
The liquid format of Unobond FC delivers wide coverage and uniform glue-line thickness. Its slight expansion fills voids in tongue-and-groove systems, reducing long-term movement. Success means firmer floors, fewer callbacks, and faster installs.
Best Practice Note
Follow flooring manufacturer spreading guides and allow squeeze-out to cure before trimming. This prevents smearing and supports a clean professional finish.
For Cabinet Makers & Furniture Manufacturers (Business Owner/Operator): High-output production bonding
The Professional's Challenge
Maintaining production speed while ensuring every panel and joint reaches structural bond strength can be challenging with slower curing adhesives.
The Adheseal Solution
Unobond FC’s liquid consistency accelerates spreading over large surfaces. The predictable 1-hour pressing time integrates seamlessly with clamping cycles, improving throughput and reducing production downtime.
Best Practice Note
Keep work areas clean and rotate stock effectively—reseal the drum lid after each use to prevent premature curing and extend product life.
For Marine Fabricators (Specifier/Installer): Timber and composite bonding in wet environments
The Professional's Challenge
Marine conditions demand adhesives that resist long-term moisture exposure, temperature swings, and substrate movement.
The Adheseal Solution
Unobond FC’s D4-grade water resistance and polyurethane resilience make it ideal for bonding timber, FC sheeting, and compatible composites in demanding environments. Success means joints that remain stable, watertight, and durable under continuous stress.
Best Practice Note
Ensure substrates are dry on the surface but contain internal moisture to activate cure. Mist non-porous materials lightly in cool or dry conditions.
Frequently Asked Questions
What is Unobond FC used for?
Unobond FC is a liquid structural polyurethane adhesive for high-coverage construction and manufacturing bonds. It’s used on timber, concrete, metals, boards and compatible plastics for general construction, flooring, furniture and cabinet making, display work and exterior woodwork, including marine-related applications where D4 water resistance is required.
Is Unobond FC waterproof and suitable for exterior or marine environments?
Yes, Unobond FC is classified as a D4 waterproof adhesive and withstands a 72-hour boiling water test. This rating makes it suitable for exterior use and marine-influenced environments when applied to sound, compatible substrates using the recommended preparation and clamping procedures.
How long does Unobond FC take to set and fully cure?
Unobond FC typically skins in about 10 minutes and reaches full cure in approximately 24 hours at 23°C and 50% relative humidity. Working time is around 15 minutes, with a pressing time of roughly 1 hour at 0.6 N/mm². Cooler temperatures, low humidity or very dry substrates will extend these times, so allow additional curing under harsh conditions.
Can Unobond FC be used as a gap filler?
No, Unobond FC is an adhesive, not a gap-filling mastic, and its strength is reduced when used to fill wide gaps. It is designed for close-fitting joints with a glue line of about 0.1–0.25 mm that can be clamped or mechanically fixed. For filling cracks and non-structural voids, use a dedicated gap filler from the Adheseal range instead of relying on Unobond FC.
What substrates will Unobond FC bond to, and do they need primer?
Unobond FC bonds to most common building substrates without primer when they are clean, sound and contain adequate moisture. Suitable substrates include softwood, hardwood, plasterboard, particleboard, aluminium, iron, steel, sheet metal, polystyrene, insulation foam, concrete, FC sheeting, brick, masonry, veneer, melamine and many plastics (with testing recommended). Light abrasion and solvent cleaning are critical on metals and dense surfaces to achieve predictable performance.
Applications & Benefits
| Application / Use Case | Key Benefit | Primary Trades |
|---|---|---|
| High-coverage bonding of timber, boards and concrete in general construction | Liquid format spreads quickly over large areas while delivering a structural D4 waterproof bond for long-term durability. | Builders, Carpenters, General Contractors |
| Flooring systems and squeak reduction in tongue-and-groove panels | Slight expansion fills voids in joints, helping prevent movement and noise for a solid, professional floor finish. | Flooring Installers, Builders, Shopfitters |
| Manufacturing of furniture, cabinets and joinery components | Defined working and pressing times integrate with clamping cycles, supporting efficient production with fewer rejects. | Cabinet Makers, Furniture Manufacturers, Joiners |
| Display signs and mixed-material assemblies | Reliable bonding of metals, boards and compatible plastics reduces the need for multiple adhesive systems. | Shopfitters, Sign Manufacturers, Fabricators |
| Exterior and marine-related woodwork | D4 water resistance and polyurethane resilience support tough, moisture-exposed joints. | Boat Builders, Marine Fabricators, Exterior Joiners |
Applying Unobond FC: Enhanced Protocols & Best Practices
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1. Assess and Prepare Substrates
Correct surface preparation is essential for structural bond strength and long-term durability.
Porous substrates (timber, concrete, boards)
Ensure substrates are structurally sound, stable and free from dust, loose or friable material, oils, grease, curing compounds and other contaminants. Allow new concrete to cure for at least 28 days before bonding and remove surface laitance by mechanical means if necessary.
Non-porous and metallic substrates
Lightly abrade metals and dense surfaces, then use the two-wipe method with a suitable solvent such as xylene and fresh cloths. Replace cloths regularly to avoid spreading contamination back over the surface.
Timing: Allow any solvent cleaner to evaporate fully before applying Unobond FC to avoid trapping solvent in the bond line.Pro Tip: Substrates should contain enough internal moisture to activate curing but must be free of standing surface water. Aim for around 8% moisture in timber for consistent performance. -
2. Dispense and Spread the Adhesive
The liquid format of Unobond FC allows efficient coverage across large areas when spread correctly.
Dispensing from drum
Open the drum and use appropriate dispensing equipment or a decanting process to apply adhesive onto one of the bonding surfaces. Keep the adhesive band approximately 10 mm in from external edges to minimise squeeze-out.
Spreading to correct glue-line thickness
Use a spatula or suitable spreader to distribute Unobond FC evenly, targeting a glue line of approximately 0.1–0.25 mm (maximum 0.5 mm). Ensure complete coverage without pooling.
Timing: Unobond FC skins in about 10 minutes at 23°C and 50% RH; complete spreading and assembly within this window.Pro Tip: On very dry or non-porous substrates, a light mist of water on the mating surface can assist moisture cure, especially in cool or low-humidity conditions. -
3. Assemble, Clamp and Allow to Cure
Firm, even pressure across the joint ensures structural performance and predictable results.
Bringing joints together
Bring the bonding surfaces together immediately after spreading and clamp tightly and evenly. Generate enough pressure to close joints and see some controlled squeeze-out along the edges.
Pressing and cure time
Maintain clamping pressure for at least 60 minutes at 23°C and 50% RH with a pressing load of roughly 0.6 N/mm². Full cure is typically reached after about 24 hours, although low temperatures and humidity will slow the reaction.
Timing: Extend clamping and cure times if conditions are cooler, drier or if substrate moisture content is low.Pro Tip: Let squeeze-out cure fully before trimming it away with a sharp blade. Trying to wipe it while wet will smear adhesive across the surface and make cleanup harder. -
4. Cleanup and Drum Storage
Good cleanup and storage habits protect tools, maintain product quality and keep sites tidy.
Cleaning tools and spills
Clean tools and fresh spills with xylene while the adhesive is still wet. Once cured, Unobond FC can only be removed mechanically by scraping or sanding.
Personal cleanup and storage
Use appropriate hand wipes for skin cleaning and avoid solvent-based skin cleaners. After use, reseal the drum lid securely to limit exposure to air and store between 15°C and 25°C in a cool, dry place.
Timing: Perform solvent cleaning immediately after application. Once adhesive cures, expect mechanical removal only.Pro Tip: Date-mark opened drums and rotate stock so older product is used first, maintaining predictable performance across projects.
Limitations & Safety
Product Limitations
Unobond FC is not suitable as a gap-filling mastic. When used to fill gaps instead of bonding close-fitting joints, the strength of the bond is reduced.
Maximum performance requires pressure during curing. Always use clamps, screws or nails to maintain joint compression throughout the pressing time.
The adhesive depends on moisture to cure and will not cure correctly in totally confined spaces without access to atmospheric humidity or moisture from substrates.
Unobond FC is not recommended for mirror adhesion. For mirror work, use a dedicated mirror adhesive such as High Power 609 and always test first.
Unobond FC is not suitable for structural glazing applications. For structural glazing, use appropriate glazing silicones such as N-80 or N-60 glazing silicone in line with project specifications.
Safety & Handling Requirements
Personal Protective Equipment
Wear overalls, suitable gloves, safety glasses and, where inhalation risk exists, an organic vapour/particulate respirator meeting AS/NZS 1715 and AS/NZS 1716. Available information suggests gloves made from nitrile rubber are suitable for intermittent contact, but users should confirm suitability for their conditions. Always wash hands before eating, drinking, smoking or using the toilet and wash contaminated clothing before reuse.
Ventilation Requirements
Use Unobond FC only with adequate ventilation, particularly in enclosed work areas. Avoid breathing vapours or mist. Improve natural ventilation where possible or use appropriate respiratory protection if ventilation is limited.
Fire & Handling Precautions
Store the 6 kg drum in a cool, dry place between 15°C and 25°C. Keep containers tightly closed when not in use and prevent spills from entering drains or waterways. Although the cured product is classified as uninflammable, standard industrial housekeeping practices should be followed.
Emergency First Aid
Eyes:
Rinse the open eye with running water for several minutes, lifting eyelids occasionally. Seek medical attention after thorough rinsing, especially if irritation persists.
Skin:
Wash immediately with soap and water and rinse thoroughly. If irritation continues, consult a doctor. Do not use solvents to remove adhesive from skin.
Inhaled:
Move the person to fresh air and keep them warm and at rest. If symptoms persist, seek medical advice. In cases of unconsciousness, place the patient in the recovery position and obtain urgent medical assistance.
Swallowed:
Do not induce vomiting. Rinse mouth with water if the person is conscious and call for medical help immediately. Treat symptomatically and be aware that effects may be delayed.
Seek medical attention immediately in all cases of serious exposure. For urgent advice, contact a doctor or Poisons Information Centre (Australia 13 11 26, New Zealand 0800 764 766).
Unobond FC Application Guide
Timber (Softwood & Hardwood)
Surface Preparation
Ensure timber is structurally sound, stable and free from dust, dirt, coatings and surface contamination. Lightly sand where required to expose fresh timber and remove sanding dust. Target a moisture content of at least around 8% while keeping the surface free of standing water.
Primer Requirements
No primer is typically required on clean, sound timber substrates.
For critical structural joints, ensure close-fitting contact and adequate clamping pressure to achieve a glue line of 0.1–0.25 mm and structural performance.
Concrete, Masonry & FC Sheeting
Surface Preparation
Allow new concrete to cure for at least 28 days. Remove laitance, dust, curing compounds and loose material by mechanical means if necessary, then vacuum clean. Substrates should be dry on the surface but contain sufficient internal moisture to activate curing.
Primer Requirements
Primer is usually not required on sound, well-prepared mineral substrates.
On weak or highly contaminated surfaces, perform adhesion testing and, where needed, use additional mechanical fixing as directed by project specifications.
Metals (Aluminium, Iron, Steel, Sheet Metal)
Surface Preparation
Lightly abrade metal surfaces to remove oxidation and create a key. Clean thoroughly using the two-wipe method with a suitable solvent such as xylene and fresh lint-free cloths to remove oils, cutting fluids and release agents.
Primer Requirements
Primer generally not required on bare, properly prepared metals.
Conduct adhesion tests where metals are coated or unknown. Ensure joints are designed so the adhesive line has access to atmospheric humidity for correct curing.
Plasterboard, Particleboard, Veneer & Melamine
Surface Preparation
Confirm boards are dry, firmly fixed where required and free from dust or friable material. Remove dust with vacuum or a clean cloth. Lightly scuff glossy melamine and wipe clean to remove release agents and handling contaminants.
Primer Requirements
Primer usually not required on standard board and laminate surfaces when correctly prepared.
For specialty laminates or critical applications, use the Adheseal Bond Adhesion Testing (BAT) program to confirm system performance before full-scale installation.
Polystyrene & Insulation Foam
Surface Preparation
Ensure foam panels are clean, dry and free from dust or loose particles. Avoid damaging the surface skin during cutting or trimming so the adhesive can wet out evenly without excessive absorption.
Primer Requirements
No primer is normally required on compatible foam substrates.
Carry out a small-area test to confirm adhesive expansion and cure are suitable for the foam density and design before proceeding with full-scale installation.
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