How do polyurethane adhesives cure?

They react with moisture. One surface must hold at least 8% moisture, or you mist the mating face with water. In dry, sealed spaces they will not cure.

Can I use polyurethane adhesive on boats?

Yes. Unobond and Unobond FC carry a D4 water-resistance rating. The bond passed a 72-hour boiling water test, so it suits marine work and full weather exposure.

Do I need to clamp polyurethane adhesive?

Yes. Clamp for at least one hour at 23°C. Use about 50 PSI on softwoods and 150 PSI on hardwoods. Keep the glue line under 0.5 mm for full strength.

Can polyurethane adhesive fill gaps?

No. It is a bond adhesive, not a filler. Strength drops past a 0.5 mm glue line. Fill cracks and gaps with a gap-filling product instead.

How soon can I drive after a windscreen bond?

NP-60 passes its crash test with dual airbags one hour after bonding at 23°C. Do not clean old sealant with alcohol. Alcohol stops the cure.

Does polyurethane adhesive bond near silicone?

No. Keep it away from cured or uncured silicone and hybrid sealants. Apply above 5°C. Cold slows the cure and weakens the bond. Match the product spec to the job conditions before you start.

Polyurethane Adhesives for Timber & Construction

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Polyurethane Adhesives

Polyurethane adhesives are used where a tough, moisture-curing bond is needed across timber, construction materials or automotive glass. Adheseal's polyurethane adhesive range is focused on bonding products rather than flexible joint sealants, with options for D4 timber bonding, structural joinery, marine and exterior work, and windscreen installation. Polyurethane adhesive for...

Polyurethane adhesive for timber and construction

Polyurethane glue is commonly selected for timber and mixed-material bonding because it cures through moisture and can provide strong, durable adhesion across compatible porous and non-porous substrates. For joinery, exterior construction and marine work, the bond must also tolerate moisture and changing service conditions. Always match the adhesive to the substrates, joint design and exposure specified in the product data sheet.

Adheseal Unobond is a D4 polyurethane timber adhesive supplied in cartridge format for high-strength bonding in joinery, marine and exterior construction. It is suited to jobs where a compact, gun-applied polyurethane adhesive is easier to control at the bond line. Unobond FC provides the same polyurethane adhesive category in a larger 6kg format for higher-volume structural timber and fabrication work.

Polyurethane windscreen adhesive

Automotive glazing has different requirements from timber bonding. Adheseal NP-60 is a one-part polyurethane windscreen adhesive designed for direct glazing and vehicle glass replacement, where fast return to service and reliable adhesion are critical. Windscreen bonding should follow the specified surface preparation, primer requirements and cure conditions for the vehicle and adhesive system.

Choosing the right polyurethane glue

When comparing polyurethane adhesives, check working time, cure rate, substrate compatibility, water resistance, application temperature and required clamping or fixture time. A D4 polyurethane wood adhesive is not interchangeable with a windscreen adhesive, even though both use polyurethane chemistry. The intended application and tested system should determine the product choice.

If the job is primarily sealing expansion joints, façade perimeters, precast panels or other moving construction joints, use the dedicated Polyurethane Sealants range instead. For additional timber and fabrication options, browse our Joinery Adhesives.