Soudal Pro 45P - Ultra Fast Set D4 Polyurethane Adhesive

Health & Safety Recommendations

Always read the packaging label and Safety Data Sheet before use, and follow all the stated precautions for handling polyurethane adhesives. Wear polythene or nitrile disposable gloves, suitable eye protection and appropriate workwear, and avoid contact with the skin or eyes wherever possible. Soudal Pro 45P is a moisture-curing PU timber adhesive, so any uncured material should be handled carefully and cleaned promptly before it begins to react and cure.

Maintain good site hygiene throughout the work. Do not eat, drink or smoke while applying the adhesive, and wash hands thoroughly once you have finished. Keep the working area well ventilated, particularly in enclosed workshops, joinery areas or internal spaces where several bonds are being completed in one session. If uncured adhesive comes into contact with the skin, remove it immediately and wash with soap and water. If it enters the eyes, rinse carefully with plenty of clean water and seek medical advice if any irritation persists.

Substrate Suitability

Soudal Pro 45P has been designed for high-strength timber bonding and general construction bonding, in situations where a fast-curing, water-resistant PU adhesive is required. It offers good adhesion to wood, concrete, stone, carton, laminate and many other porous and non-porous construction substrates, which makes it well suited to professional joinery, timber construction, frame assembly and general building applications.

The product is particularly well matched to wooden materials and timber elements that require D4 water resistance to EN 204, including applications exposed to high humidity or exterior weather influence (assuming the joint design is appropriate). It can also be used wherever a fast PU wood adhesive is needed for demanding bonding work involving wooden construction elements, door and window frames, damp or humid timber, and mixed building materials.

Soudal Pro 45P is not suitable for PE, PP or PTFE (Teflon®), as adhesion to these low-surface-energy plastics is unreliable. Because surface condition, density and finish can vary considerably between materials and manufacturers, a preliminary adhesion and compatibility test is recommended on every unfamiliar substrate before full application.

Surface Preparation

The substrate must be clean, sound and free from dust, grease, oil, loose particles and contamination. Timber faces should be properly prepared so the adhesive can wet the surface and form a strong bond. Concrete, stone and other mineral surfaces should be stable and free from friable material, laitance or surface coatings that could weaken adhesion. Any existing adhesive residues, waxes, release agents or coatings that might interfere with bonding should be removed before application begins.

Soudal Pro 45P cures on exposure to moisture in the air or in the material itself. During curing, it foams lightly, which helps improve penetration and can also assist with filling minor irregularities in the bond line. A light misting of the surface with clean water can accelerate the hardening process and increase the filling character of the adhesive. This should be done carefully and sparingly; the surface needs to be lightly moistened, not saturated or left with standing water.

For the best results, dry-fit the parts before applying the adhesive. Because Pro 45P has a short open time of approximately 5 minutes, components should be cut, aligned and ready for assembly before any adhesive is applied.

Application Method

Apply Soudal Pro 45P using a fine-toothed comb, adhesive spreader or brush onto one of the materials being bonded. Spread the adhesive evenly across the bonding area, making sure the surface is sufficiently covered but not overloaded. The liquid polyurethane consistency allows for controlled application, while the viscosity of approximately 2,000–4,000 mPa.s helps the adhesive remain workable during spreading.

Bring the two parts together within a maximum of approximately 5 minutes. This short open time is one of the key features of Pro 45P and is what supports such fast assembly, but it does also mean the work must be properly organised before application begins. Once the parts have been brought together, clamp them for at least 30 minutes. Clamping during curing is essential for achieving the final maximum strength, as it keeps the bond line tight and ensures proper contact between both surfaces.

Use a pressing pressure of approximately 1 kg/cm² to 2 kg/cm² wherever practical. The pressure should be firm and even, without distorting the timber or forcing all the adhesive out of the joint. Correct clamping is especially important in door and window frame manufacture, joinery assembly, construction timber bonding and any application where long-term strength and D4 water resistance are required.

Coverage

Coverage is approximately 150 g/m², depending on the substrate, surface absorbency, application method and the flatness of the materials being bonded. Smooth, accurately machined timber faces will generally use less adhesive than rougher or more absorbent construction surfaces. Where the adhesive is being used to help fill slight irregularities, consumption may increase accordingly.

For planning purposes, 1kg of adhesive will cover approximately 6.6m² at 150 g/m² under ideal conditions. This should be treated as a guide only, as real-world site and workshop usage can vary. Allow additional material for rough timber, porous surfaces, edge losses, squeeze-out and test bonding.

Curing Time

Soudal Pro 45P is a moisture-curing polyurethane adhesive with an open time of approximately 5 minutes. Once the parts have been assembled, they should be clamped for at least 30 minutes. The adhesive builds strength quickly, although the final cure and full performance will depend on temperature, moisture availability, substrate type, adhesive thickness and clamping quality.

A light water spray can accelerate curing and improve the filling character of the adhesive, particularly where the substrates are very dry. However, excessive water should be avoided, as over-wetting can increase foaming and may affect the neatness of the bond line. The product has been designed for application between 5°C and 35°C. Once cured, it offers a service temperature resistance from -30°C to +100°C, making it suitable for demanding internal and external timber bonding applications.

Soudal Pro 45P achieves a shear strength of at least 10 MPa and meets the D4 durability classification to EN 204, provided it is applied correctly and used within an appropriate joint design. This makes it well suited to high-humidity interiors and weather-exposed exterior timber assemblies where a water-resistant wood adhesive is required.

Cleaning

Uncured Soudal Pro 45P can be removed from substrates and tools using Soudal Soudafoam Gun & Foam Cleaner. Cleaning should always be carried out immediately after application, before the adhesive begins to cure. Prompt cleaning is particularly important on visible timber, laminate, stone or finished building materials, as cured polyurethane adhesive is very difficult to remove without mechanical action.

Once cured, the product can only be removed mechanically. This may involve scraping, sanding, trimming or abrasion, depending on the substrate and the extent of the contamination. Mechanical removal can damage finished surfaces, so it is always better to apply the adhesive carefully, remove any squeeze-out while it is still fresh and keep tools clean throughout the work.

Limitations

Soudal Pro 45P is not suitable for PE, PP or PTFE (Teflon®). It should not be used on unstable, contaminated or weak substrates, as the final bond strength depends entirely on the strength and cleanliness of the surfaces being joined. Although the adhesive has a light foaming action and can help fill small irregularities, it should not be used to compensate for badly fitting joints, excessive gaps or poor workmanship.

Because the adhesive cures by reacting with moisture, application conditions will affect overall performance. Very dry materials may slow curing unless lightly moistened, whereas excessive moisture can increase foaming and reduce control. The product should be applied within its recommended temperature range of 5°C to 35°C. A preliminary adhesion and compatibility test is recommended where the substrate is unfamiliar, coated, highly dense, unusually porous or critical to the finished assembly.

Other Information

Soudal Pro 45P is a professional fast PU wood adhesive with a 93% solid content, a density of approximately 1.11 g/ml and a D4 durability classification to EN 204. It has been designed for demanding timber bonding work where high strength, water resistance and fast handling are required, including general joinery, door and window frame production, timber construction elements and damp or humid timber applications.

For the best results, prepare the surfaces correctly, apply an even adhesive layer, assemble within the 5-minute open time and clamp for at least 30 minutes. Proper pressure during curing is essential for maximum final strength. Used correctly, Soudal Pro 45P delivers a fast, strong and water-resistant polyurethane bond, well suited to professional wood bonding and construction adhesive applications where long-term durability really matters.

Q) What is Soudal Pro 45P and what is it designed for?

A) Soudal Pro 45P is a professional-quality, fast-drying, water-resistant liquid polyurethane timber adhesive developed for high-strength wood bonding in demanding joinery and construction applications. Based on moisture-curing polyurethane technology, it offers excellent D4 water resistance to DIN EN 204, making it suitable for both interior areas exposed to high relative humidity and exterior timber assemblies subject to direct weather influence. Pro 45P is particularly well suited to door and window frame manufacture, wooden construction elements, corner connections and general joinery bonding. With an ultra-fast open time of around 5 minutes and a minimum pressing time of just 30 minutes, it is designed to speed up production and installation work while delivering long-term bond strength.

Q) What lead types of timber and substrates can Soudal Pro 45P bond?

A) Soudal Pro 45P offers good adhesion to wood, concrete, stone, carton, laminate and many other porous and non-porous construction substrates, making it well suited to professional joinery, frame assembly and general building applications. It is particularly effective on wooden materials and timber elements where D4 water resistance is required, including damp or humid wooden surfaces and suitable wet wood types. This makes it adaptable to real-world workshop and site conditions where timber moisture content may vary. However, it is not suitable for low-surface-energy plastics such as PE, PP or PTFE (Teflon®). Because surface conditions vary widely, a preliminary adhesion test is recommended on every unfamiliar substrate before full application.

Q) Where can Soudal Pro 45P be used in joinery and construction work?

A) Soudal Pro 45P is designed for a wide range of professional bonding situations involving timber and mixed building materials. Typical applications include door and window frame manufacture with corner connections, bonding wooden construction elements, exterior timber bonding subject to weather exposure, and interior high-humidity applications where standard wood glues would not perform reliably. It is also a strong choice for general joinery bonding, heavy-duty wood bonding, and timber assemblies where damp or humid wood is being processed. Its foaming penetration action makes it useful on slightly uneven bond interfaces, and its D4 durability classification supports use in workshop production and on-site work where long-term moisture and weather resistance are essential to the finished assembly.

Q) When should Soudal Pro 45P be applied during a project?

A) Soudal Pro 45P should be applied once the timber components have been cut, prepared and dry-fitted, and once the working environment is suitable for moisture-curing polyurethane adhesives. The recommended application temperature range is between 5°C and 35°C, so it should not be used in freezing conditions or in extreme heat that would shorten the already brief 5-minute open time. Because the open time is short, all parts must be ready for immediate assembly before adhesive is applied. The timing should also allow for at least 30 minutes of uninterrupted clamping. Apply Pro 45P before any final finishing work, ensuring the joint is positioned, clamped and supported throughout the initial cure stage.

Q) What are the main advantages of using Soudal Pro 45P?

A) Soudal Pro 45P offers a strong combination of advantages tailored to professional users. It delivers ultra-fast curing performance, with around a 5-minute open time and a 30-minute minimum pressing time, allowing rapid production and installation. It achieves D4 water resistance to DIN EN 204, supporting use in high-humidity interiors and weather-exposed exterior assemblies. It produces high-strength bonds with shear strength of at least 10 MPa, and its foaming penetration action helps fill small bond cavities and surface irregularities. It is also suitable for damp or humid wood, has strong temperature resistance from -30°C to +100°C, and is ideal for D4 frame manufacture. Together, these benefits make it a highly efficient and dependable timber adhesive.

Q) What technical performance does Soudal Pro 45P offer?

A) Soudal Pro 45P has a clearly defined technical profile suited to demanding bonding work. It is a liquid polyurethane adhesive with approximately 93% solid content and a density of around 1.11 g/ml, with a viscosity of approximately 2,000 to 4,000 mPa.s for controlled spreading. The open time is approximately 5 minutes and minimum pressing time is 30 minutes. It achieves a shear strength of at least 10 MPa, meeting the D4 durability classification to DIN EN 204. The cured adhesive offers a service temperature range from -30°C to +100°C, with a recommended pressing pressure of 1 to 2 kg/cm². Coverage is approximately 150 g/m², offering an efficient balance between productivity and bond performance.

Q) How should surfaces be prepared before applying Soudal Pro 45P?

A) For reliable bonding, substrates must be clean, sound and free from dust, grease, oil, loose particles and contamination. Timber faces should be properly prepared so the adhesive can wet the surface and form a strong bond, while concrete, stone and other mineral surfaces should be stable and free from friable material, laitance or surface coatings. Existing adhesive residues, waxes, release agents or coatings that could interfere with bonding must be removed before application. Dry-fit the parts first, since Pro 45P has only a 5-minute open time. Where substrates are very dry, a light misting of clean water can accelerate curing and improve the filling character, but the surface should be lightly moistened rather than saturated.

Q) How is Soudal Pro 45P applied to a timber joint?

A) Soudal Pro 45P is applied using a fine-toothed comb, adhesive spreader or brush onto one of the materials being bonded. Spread the adhesive evenly across the bonding area, ensuring sufficient coverage without overloading the joint. The liquid PU consistency and viscosity of around 2,000 to 4,000 mPa.s help the adhesive remain workable during spreading. Bring the two parts together within the approximate 5-minute open time, since this short window is what supports the rapid assembly cycle. Once the parts are positioned, clamp them firmly for at least 30 minutes using a pressing pressure of approximately 1 to 2 kg/cm². The pressure should be firm and even, without distorting the timber or expelling adhesive from the joint.

Q) What pressing pressure and clamping time are recommended for Soudal Pro 45P?

A) Soudal Pro 45P should be clamped for a minimum of 30 minutes after assembly, using a pressing pressure of approximately 1 kg/cm² to 2 kg/cm² wherever practical. This pressure must be firm and even across the bonded area, holding the joint tight while the adhesive cures without distorting the timber or forcing the adhesive entirely out of the joint. Correct clamping is essential for achieving the final maximum strength and the full D4 water resistance, as it keeps the bond line tight and ensures proper contact between both surfaces. Clamping is particularly important in door and window frame manufacture, joinery assembly and construction timber bonding, where long-term strength and weather resistance are non-negotiable performance requirements.

Q) How long does Soudal Pro 45P take to cure?

A) Soudal Pro 45P is a moisture-curing polyurethane adhesive with an open time of approximately 5 minutes. Once the parts have been assembled, they should be clamped for at least 30 minutes, during which time the adhesive builds strength quickly. Final cure and full performance depend on temperature, moisture availability, substrate type, adhesive thickness and clamping quality. A light water spray can accelerate curing and improve the filling character of the adhesive, particularly where substrates are very dry, but excessive water should be avoided. The product is designed for application between 5°C and 35°C. Once cured, it offers a service temperature resistance from -30°C to +100°C, suitable for demanding internal and external timber bonding applications.

Q) Is Soudal Pro 45P suitable for exterior timber applications?

A) Yes, Soudal Pro 45P is particularly well suited to exterior timber bonding where direct weather exposure is expected, provided the joint design is appropriate for the conditions. Its D4 durability classification to DIN EN 204 confirms suitability for interior applications with frequent long-term exposure to water or condensation, as well as exterior applications exposed to weather when properly constructed. This makes it ideal for door and window frame manufacture, wooden construction elements and exterior joinery work. The cured bond delivers a shear strength of at least 10 MPa and remains stable across a service temperature range from -30°C to +100°C, helping bonded components remain dependable through seasonal movement and external weathering.

Q) Can Soudal Pro 45P be used on damp or humid wood?

A) Yes, Soudal Pro 45P is specifically suited for use on damp or humid wooden surfaces, as well as on suitable wet wood types. Because the adhesive cures by reacting with moisture, the presence of moisture in the timber can actually support the curing process rather than hinder it. This makes the product highly practical in real-world conditions where timber may not always arrive in a perfectly dry state, particularly on construction sites or in workshops handling outdoor-stored stock. The foaming penetration action also helps to fill small cavities and improve contact across less-than-perfect timber interfaces. However, excessive moisture should still be avoided, as it can increase foaming and affect the neatness of the bond line.

Q) What surfaces is Soudal Pro 45P not suitable for?

A) Although Soudal Pro 45P has broad compatibility, it is not suitable for low-surface-energy plastics such as PE, PP or PTFE (Teflon®), as adhesion to these materials is unreliable. It should also not be used on unstable, contaminated or weak substrates, as the final bond strength depends entirely on the strength and cleanliness of the surfaces being joined. Although the adhesive has a light foaming action and can help fill small irregularities, it should not be used to compensate for badly fitting joints, excessive gaps or poor workmanship. Because surface condition, density and finish vary considerably between materials, a preliminary adhesion and compatibility test is recommended on every unfamiliar, coated, highly dense or critical substrate.

Q) What does the foaming penetration action of Soudal Pro 45P do?

A) The foaming penetration action of Soudal Pro 45P is one of its most useful practical features. As the adhesive cures by reacting with moisture, it lightly foams and expands into small cavities, helping to fill minor irregularities between surfaces and improve contact on less-than-perfect timber interfaces. This is particularly valuable when bonding rougher timber, construction-grade wood, or components where the contact faces are not as precise as those found in finely machined joinery. The result is improved penetration into the substrate, better wetting of the bond surfaces, and a more consistent bond line overall. However, it should not be relied upon to compensate for badly fitting joints or excessive gaps in poorly prepared work.

Q) How is Soudal Pro 45P cleaned during and after application?

A) Uncured Soudal Pro 45P can be removed from substrates and tools using Soudal Gun and Foam Cleaner. Cleaning should always be carried out immediately after application, before the adhesive begins to cure, as cured polyurethane adhesive is very difficult to remove without mechanical action. Prompt cleaning is particularly important on visible timber, laminate, stone or finished building materials, where cured residues can mark the surface. Once cured, the product can only be removed mechanically through scraping, sanding, trimming or abrasion, depending on the substrate and contamination. Because mechanical removal can damage finished surfaces, it is always better to apply the adhesive carefully, remove squeeze-out while still fresh and keep tools clean throughout the work.

Q) What coverage can be expected from Soudal Pro 45P?

A) Soudal Pro 45P offers a coverage rate of approximately 150 g/m², depending on the substrate, surface absorbency, application method and the flatness of the materials being bonded. Smooth, accurately machined timber faces will generally use less adhesive than rougher or more absorbent construction surfaces. Where the adhesive is being used to help fill slight irregularities, consumption may increase accordingly. For planning purposes, 1 kg of adhesive will cover approximately 6.6 m² at 150 g/m² under ideal conditions. This figure should be treated as a guide only, as real-world site and workshop usage can vary. Allow additional material for rough timber, porous surfaces, edge losses, squeeze-out and any test bonding carried out before full production work.

Q) What standards and certifications does Soudal Pro 45P meet?

A) Soudal Pro 45P meets the D4 durability classification under DIN EN 204, which is a key durability standard for wood adhesives. The D4 rating indicates suitability for interior applications with frequent long-term exposure to water or condensation, as well as for exterior applications exposed to weather when properly constructed. This is the highest durability classification under EN 204 and confirms the product’s suitability for demanding professional joinery and construction work. The adhesive also achieves a shear strength of at least 10 MPa, confirming it has been designed for demanding wood bonding rather than light-duty fixing. Together, these standards support its use in professional joinery, timber construction and frame manufacture where bond strength is critical.

Q) What are some practical tips for getting the best results with Soudal Pro 45P?

A) For the best results with Soudal Pro 45P, prepare and dry-fit all components before applying any adhesive, since the open time is only around 5 minutes. Apply an even layer using a fine-toothed comb, spreader or brush, ensuring sufficient coverage without overloading the joint. Where substrates are very dry, lightly mist the surface with clean water to accelerate curing and improve filling character, but avoid saturation. Clamp parts immediately for at least 30 minutes at a pressure of 1 to 2 kg/cm², ensuring even firm contact across the joint. Remove squeeze-out promptly with Soudal Gun and Foam Cleaner before curing begins. Always work within the recommended temperature range of 5°C to 35°C for reliable performance.

Q) What are the limitations of Soudal Pro 45P?

A) Soudal Pro 45P has several important limitations to be aware of. It is not suitable for PE, PP or PTFE (Teflon®), and should not be used on unstable, contaminated or weak substrates, since final bond strength depends on substrate quality. While the foaming action helps fill small irregularities, it should not be used to compensate for badly fitting joints, excessive gaps or poor workmanship. Because the adhesive cures by reacting with moisture, very dry materials may slow curing unless lightly moistened, while excessive moisture can increase foaming and reduce control. The product must be applied within the temperature range of 5°C to 35°C. A preliminary adhesion test is recommended on unfamiliar, coated, dense or critical substrates before committing to full application.

Q) What health and safety precautions should be followed when using Soudal Pro 45P?

A) Always read the packaging label and Safety Data Sheet before use, and follow all stated precautions for handling polyurethane adhesives. Wear polythene or nitrile disposable gloves, suitable eye protection and appropriate workwear, avoiding contact with skin or eyes wherever possible. Maintain good site hygiene throughout the work, and do not eat, drink or smoke while applying the adhesive, washing hands thoroughly once finished. Keep the working area well ventilated, particularly in enclosed workshops or internal spaces where several bonds are being completed in one session. If uncured adhesive contacts the skin, remove it immediately and wash with soap and water; if it enters the eyes, rinse carefully with plenty of clean water and seek medical advice if irritation persists.

Technical Data Sheet

Safety Data Sheet