Adheseal Unobond Polyurethane Adhesive

Adheseal Unobond is a single-pack, solvent-free, moisture-curing D4 polyurethane adhesive for structural timber bonding, joinery, furniture and cabinet manufacture, exterior woodwork and wooden boat building. Its gel consistency makes this cartridge-applied polyurethane glue easy to control on close-fitting joints, while the cured bond is built for demanding internal, external and marine applications.

Unobond bonds porous materials to porous or compatible non-porous materials when at least one mating surface provides enough moisture to activate the cure. It foams and expands slightly as it reacts, helping the adhesive work into small surface irregularities and maximise contact across the bond line.

D4 polyurethane adhesive for timber, joinery and marine work

Unobond is particularly well suited to professional timber and fabrication work where strong, durable bonding and controlled application are important. Typical applications include furniture and cabinet manufacture, floor mouldings and skirting boards, display signs, exterior woodwork, wooden boat building and general construction bonding.

• D4 water-resistant classification: Unobond's cured bond withstands a 72-hour boiling water test.
• Structural bond strength: tensile strength of 5 N/mm².
• Single-pack system: ready to use with no mixing required.
• Working time: approximately 15 minutes at 23°C and 50% relative humidity, with a skin time of about 10 minutes.
• Full cure: approximately 24 hours at 23°C and 50% relative humidity, depending on temperature, humidity and substrate moisture.
• Service temperature: -30°C to +100°C after cure.

What materials can Unobond bond?

Unobond bonds common building and fabrication materials including softwood and hardwood, veneer, melamine, particleboard, plasterboard, fibre cement sheeting, concrete, brick and masonry, aluminium, iron, steel, sheet metal, stainless steel, polystyrene and insulation foam. Some plastics can also be bonded after compatibility testing.

Compatible materials can be bonded to themselves or to one another, provided moisture is available to activate the polyurethane cure. This makes Unobond useful for mixed-material assemblies as well as structural timber joints.

How to apply Unobond polyurethane glue

Surfaces must be structurally sound, stable, clean and free from dust, oil, grease, release agents, curing compounds and other contamination. Concrete should be cured for at least 28 days. Metal surfaces should be lightly sanded and cleaned with a suitable solvent such as Adheseal Xylene.

All joints must be close fitting. Aim for a glue-line thickness of 0.1 mm to 0.25 mm and do not exceed 0.5 mm. Apply between 5°C and 35°C, spread the adhesive before the skin forms, bring the surfaces together immediately and clamp evenly. At 23°C and 50% relative humidity, clamps should remain in place for at least 60 minutes. Use approximately 50 PSI clamping pressure for softwoods and 150 PSI for hardwoods.

At least one surface must contain enough moisture to trigger the cure, with a minimum moisture content of 8%. In dry, cool conditions or when bonding non-porous materials, a light mist of water on the opposing surface can assist curing. Allow squeeze-out to cure before cutting it away rather than wiping it while wet.

Important limitations

• Not a gap filler: Unobond is an adhesive, not a mastic. Bond strength is reduced when it is used to fill gaps instead of joining close-fitting faces.
• Pressure is required during cure: clamp, screw or nail the assembly as appropriate to maintain contact.
• Do not use in totally confined or moisture-starved spaces: the polyurethane requires substrate moisture or atmospheric humidity to cure.
• Do not use for mirror bonding or structural glazing.
• Test plastics and potentially incompatible materials before commercial use.

Unobond or Unobond FC?

Choose Unobond when you want a cartridge-applied gel polyurethane adhesive for controlled application in joinery, timber assembly, construction and marine work. For higher-volume workshop, manufacturing or fabrication use, Unobond FC provides a liquid polyurethane adhesive in a 6 kg bulk format with coverage of approximately 42 to 60 m² per drum, depending on the surface profile.

For the broader range of PU bonding products, including structural and automotive options, browse Polyurethane Adhesives.