Soudal Silirub 2 Premium Low Modulus Neutral Silicone

Substrate Suitability

Silirub 2 boasts excellent adhesion to a wide array of common building materials, including PVC, glass, ceramic, porcelain, metals (such as stainless steel), and wood.

However, it is important to note that Silirub 2 is not suitable for PE, PP, PTFE (Teflon®), and bituminous substrates. To ensure compatibility and the best adhesion results, conducting a preliminary test on the material in question is highly recommended.

Surface Preparation

The key to a successful sealing job lies in thorough surface preparation.

Prior to applying Silirub 2, ensure that the surfaces to be sealed are clean, dry, and devoid of any dust, grease, or other contaminants. This can often involve cleaning the area with a suitable solvent or degreaser and allowing it to dry completely.

For porous surfaces subjected to water exposure, applying Soudal Primer 150 is crucial to achieving optimal adhesion. Non-porous substrates, on the other hand, do not necessitate a primer application.

Proper preparation of the surface not only promotes excellent adhesion but also contributes to the longevity and durability of the seal.

Application Method

Applying Silirub 2 is made efficient and straightforward using a caulking gun.

Begin by cutting the nozzle of the Silirub 2 cartridge at a 45-degree angle according to the desired bead size, which helps in controlling the application with precision.

After inserting the cartridge into the caulking gun securely, apply a consistent pressure to the trigger to extrude the sealant.

Aim the nozzle into the joint or gap, ensuring it is fully filled with Silirub 2.

For a more professional finish and to facilitate the smoothing process, lightly spray the surface with a soapy solution just before the sealant starts to skin.

Coverage of any sealant product varies depending on Joint Width and Joint Depth.

Please refer to our Guide on How To Measure The Number of Tubes Required For the Job.

Joint Dimensions

• Minimum Width for Joints: 5 mm
  
  

• Maximum Width for Joints: 30 mm
  
  

• Minimum Depth for Joints: 5 mm
  
  

• Recommendation Sealing Jobs: Joint Width = 2 x Joint Depth.

Finishing

Achieving a neat and smooth finish is possible with the use of the Soudaglatt Smoothing Tool or a similar smoothing device.

Gently run the tool along the line of applied sealant to smooth and level it, creating a uniform appearance.

If a smoothing tool is not at hand, a wetted finger can also be used to carefully smooth the sealant line. This step should be performed promptly before the sealant begins to skin to ensure a clean and tidy finish.

Cleaning

For instances where Silirub 2 has not yet cured, cleaning up is straightforward with Soudal Swipex Cleaning Wipes, which can remove uncured sealant effectively.

In the case of cured sealant, mechanical removal is necessary. Soudal offers products such as Sealant Remover Spray or Silicone Remover Gel for this purpose.

It is advisable to follow the specific instructions on the product for the best results in removing cured sealant.

Q) What is Silirub 2 and what makes it unique compared to other silicone sealants?

A) Silirub 2 is a premium, low modulus neutral cure silicone sealant that distinguishes itself through its exceptional performance across a wide range of sealing applications within the building industry. Its unique features include primerless adhesion to a broad spectrum of common construction materials, quick skinning and curing times, and resistance to UV, weathering, and various chemicals. This combination of traits, alongside its 100% pure silicone composition, ensures both durability and longevity in application, setting it apart from other sealants on the market.

Q) Can Silirub 2 be applied directly to surfaces without a primer?

A) Yes, Silirub 2 offers primerless adhesion to most construction materials, which means it can be applied directly to surfaces like glass, PVC, plastics, masonry, metals, and wood without the need for a primer. This feature greatly simplifies the application process, saving both time and resources. However, for porous surfaces subjected to water exposure, a primer such as Soudal Primer 150 is recommended to achieve optimal adhesion.

Q) Can Silirub 2 be painted over after it has cured?

A) Silirub 2 is not designed to be painted over. Silicone sealants create a non-porous surface that most paints cannot adhere to effectively, which could result in the paint not bonding properly or peeling off over time. For applications where painting over the sealant is necessary, it is recommended to choose a sealant that is specifically formulated to be paint-compatible. If painting is essential for your project, consider using an Acrylic Sealant or a Hybrid Sealant that can accommodate paint adhesion. Always conduct a compatibility test in a small, inconspicuous area first or consult the manufacturer’s guidelines for paintable sealant options.

Q) What are the advantages of Silirub 2’s low modulus and neutral cure properties?

A) The low modulus property of Silirub 2 allows for exceptional flexibility, enabling the sealant to absorb movements between different materials or structural components, thereby minimizing the risk of cracking or debonding. Its neutral cure feature means it releases no acetic acid during curing, making it virtually odourless and less corrosive to metals or sensitive materials, ideal for a wide range of indoor and outdoor applications.

Q) Is Silirub 2 suitable for use in all environmental conditions?

A) Silirub 2 is engineered to withstand harsh environmental conditions, including UV radiation, extreme weather, rain, snow, ozone, and various chemicals. Its UV and weather resistance guarantee a durable and long-lasting seal in a multitude of climates, ensuring reliable performance regardless of the environmental stressors.

Q) What surfaces or materials is Silirub 2 not suitable for?

A) While Silirub 2 adheres superbly to a wide range of building materials, it is not suitable for polyethylene (PE), polypropylene (PP), PTFE (Teflon®), and bituminous substrates. For these materials, alternative sealing solutions should be considered, and a preliminary compatibility test is always recommended for best results.

Q) How should surfaces be prepared before applying Silirub 2?

A) Surface preparation is crucial for the successful application of Silirub 2. Surfaces must be clean, dry, and free of dust, grease, or other contaminants before application. Cleaning the area with a suitable solvent or degreaser and allowing it to dry completely is essential. For porous surfaces in water-loaded applications, priming the surface with Soudal Primer 150 ensures optimal adhesion.

Q) What is the recommended application temperature range for Silirub 2?

A) Silirub 2 should be applied in a temperature range between 5 °C and 35 °C. This range ensures that the sealant's properties are optimal for application and that the curing process proceeds efficiently. Applying outside of this temperature range can affect the sealant’s performance and adhesion quality.

Q) Can Silirub 2 be used for sealing joints in glazing applications?

A) Yes, Silirub 2 is ideal for sealing around glass panes in windows and doors, providing a waterproof and airtight seal that enhances energy efficiency and comfort. It is compatible with most edge seals of insulating double glazing and conventional PVB films, making it a reliable choice for glazing applications.

Q) How does Silirub 2 handle movement and expansion in construction joints?

A) Thanks to its low modulus formulation, Silirub 2 can accommodate high movement, allowing it to flex with the expansion and contraction of construction joints without cracking or losing adhesion. This makes it particularly suited for sealing expansion and movement joints in construction, ensuring structural integrity over time.

Q) What is the skin formation time and curing speed of Silirub 2?

A) Silirub 2 has a skin formation time of approximately 9 minutes and a curing speed of about 2 mm per 24 hours at 23°C and 50% relative humidity. These properties allow for a quick skinning and curing process, facilitating faster project completion times.

Q) How should Silirub 2 be applied for the best results?

A) For optimal application, use a caulking gun and cut the nozzle of the Silirub 2 cartridge at a 45-degree angle according to the desired bead size. Insert the cartridge into the caulking gun, apply consistent pressure to the trigger, and fill the joint or gap completely with Silirub 2, ensuring it is evenly distributed. For a professional finish, lightly spray the surface with a soapy solution just before the sealant begins to skin. This aids in smoothing the sealant for a neat appearance. The use of a Soudaglatt Smoothing Tool or even a wetted finger can help achieve a uniform finish by running it smoothly along the sealant line.

Q) How can Silirub 2 be cleaned off surfaces before it cures?

A) Before curing, Silirub 2 can be cleaned off surfaces using Soudal Swipex Cleaning Wipes. These wipes are specially formulated to remove uncured sealant effectively, ensuring a clean and tidy working area. It's important to clean any excess or misplaced sealant before it skins and cures to prevent any unnecessary difficulties.

Q) Is Silirub 2 resistant to chemicals?

A) Silirub 2 demonstrates resistance to a variety of chemicals, making it suitable for use in environments where exposure to mild acids, bases, detergents, and salts might occur. However, it has poor resistance to aromatic solvents, concentrated acids, and chlorinated hydrocarbons, and a preliminary test is recommended for specific applications involving chemical exposure.

Q) Can Silirub 2 be used for sealing in high-movement areas?

A) Yes, Silirub 2's low modulus formulation allows it to absorb significant movements between different materials or structural components, reducing the risk of cracking or debonding in high-movement areas. This makes it particularly effective for applications such as expansion joints, where flexibility and durability are crucial.

Q) What limitations does Silirub 2 have?

A) While Silirub 2 is versatile and suitable for a wide range of applications, it should not be used on natural stones like marble or granite due to the risk of staining. Additionally, it is not recommended for continuous water immersion applications, bonding aquariums (instead use Silirub AQ), or use on Polycarbonate materials (instead use Aquafix All Weather Sealant).

Q) How does temperature affect the application and performance of Silirub 2?

A) Silirub 2 is best applied within a temperature range of 5°C to 35°C to ensure optimal adhesion and curing. Extreme temperatures can affect the sealant's viscosity, adhesion, and curing process. Once cured, it is capable of withstanding temperatures from -60°C to +180°C, providing durable performance in a wide range of environmental conditions.

Q) Can Silirub 2 be painted over?

A) Silirub 2, being a silicone sealant, is generally not paintable. Silicone surfaces do not provide a suitable surface for paint adhesion, and paint may not adhere properly or could peel off over time. If a paintable surface is required, consider using a different type of sealant designed to be paint-compatible.

Q) Is Silirub 2 environmentally friendly?

A) Silirub 2 conforms to environmental regulations such as the LEED, focusing on low-emitting materials in adhesives and sealants. Its formulation, free from MEKO and compliant with VOC-content requirements, underscores its commitment to environmental safety and sustainability, making it a more environmentally friendly option compared to some traditional sealants.

Q) How can Silirub 2 be removed once cured?

A) Cured Silirub 2 can be removed mechanically by cutting, scraping, or peeling it away from the substrate. For more challenging removals, products like Soudal Sealant Remover Spray or Silicone Remover Gel can be used to soften or dissolve the silicone for easier removal. Always follow the product instructions for the safest and most effective results.

Q) What are the storage and shelf life of Silirub 2?

A) Silirub 2 should be stored in a cool, dry place out of direct sunlight to preserve its quality. When stored properly, it has a shelf life of up to 12 months from the date of manufacture, ensuring its performance remains consistent over time. Always check the expiry date on the packaging before use to ensure the best results.

Q) Can Silirub 2 be used in direct contact with all types of glass?

A) Silirub 2 is compatible with most types of glass, including insulating double glazing and conventional PVB films. However, it is not suitable for use with self-cleaning glass, for this application use Soudal SMX 506 Sealant. A compatibility test is recommended for specific glass types or when in doubt, to ensure that there are no adverse reactions or bonding issues.

Q) How does Silirub 2 contribute to energy efficiency in buildings?

A) By providing an airtight and waterproof seal around windows, doors, and other building envelopes, Silirub 2 significantly contributes to energy efficiency in buildings. It minimizes air leakage, thereby reducing the energy required for heating and cooling. This not only helps to lower energy bills but also reduces the carbon footprint of the building, making it an environmentally friendly choice for sustainable construction practices.

Q) Is Silirub 2 suitable for use in roofing applications?

A) Yes, Silirub 2 is an excellent choice for various roofing applications, including sealing around roofline elements, guttering, downpipes, and roofing slates. Its high movement capability, coupled with its resistance to weathering, UV, and temperature extremes, ensures a durable and long-lasting seal, preventing leaks and water damage over time.

Q) Can Silirub 2 be used in industrial settings?

A) Absolutely, Silirub 2's chemical resistance and compatibility with a wide range of materials make it suitable for sealing in various industrial environments. This includes applications such as HVAC ducting, pipework, and drainage joints, where its durable seal and resistance to chemicals and extreme conditions are particularly beneficial.

Q) How does Silirub 2 affect indoor air quality?

A) Silirub 2 is formulated to be virtually odourless and free from volatile organic compounds (VOCs) like MEKO, which can contribute to indoor air pollution. By conforming to LEED requirements for low-emitting materials, Silirub 2 ensures that indoor air quality is maintained, making it a safer choice for use in enclosed spaces.

Q) Can Silirub 2 be used for underwater applications?

A) While Silirub 2 is resistant to moisture and can withstand occasional wet conditions, it is not suitable for continuous underwater immersion. For applications requiring a sealant that will be permanently submerged, a specialised product designed for underwater use would be a more appropriate choice.

Q) How does Silirub 2 handle temperature variations?

A) Silirub 2 is designed to accommodate a wide range of temperature variations, from -60 °C to +180 °C once fully cured. Its flexible nature allows it to expand and contract without losing adhesion or integrity, ensuring a reliable seal through seasonal temperature changes and extreme weather conditions.

Q) Are there any special considerations when using Silirub 2 on metal surfaces?

A) Silirub 2 adheres well to most metal surfaces, including stainless steel, without the need for a primer. However, it's always a good practice to clean the metal surface thoroughly to remove any grease, oil, or rust for optimal adhesion. For metals prone to corrosion, Silirub 2's neutral cure formulation reduces the risk of corrosion under the sealant.

Q) Can Silirub 2 be used in conjunction with other sealants?

A) When using different reactive sealants, it's important to allow the first applied sealant, such as Silirub 2, to fully cure before applying another type. This prevents any chemical incompatibility or adhesion issues between the different sealant types. Always consult the technical data sheets of both products to ensure compatibility.

Q) What certifications does Silirub 2 hold?

A) Silirub 2 has been rigorously tested and certified to ISO 11600 F&G 25 LM standards, affirming its quality and reliability. Additionally, it meets environmental standards such as LEED for low-emitting materials, further demonstrating its commitment to quality and environmental responsibility. These certifications provide assurance of the product’s performance and suitability for a wide range of applications.

Technical Data Sheet

Declaration of Performance (DoP)

Safety Data Sheet