FAQs - For Mailers & General Know-how

Sealants (Silicones, Acrylic, PU & Hybrid)

Silicone sealant is based on silicone polymers while acrylic sealant is based on acrylate polymers. Both products perform as a sealant and barrier, and both have excellent adhesion. Acrylic sealant is more environmentally friendly and cheaper price than silicone sealant.
The main difference between silicone sealant and acrylic sealant is the fact that you cannot paint over silicone sealant, which makes acrylic sealant the perfect choice for filling gaps and sealing around areas that need to be painted.

Acrylic sealant can be used for sanitary application, but silicone is generally preferred because silicone sealant is the best for sealing around bathtubs, showers, and basins, etc. Silicone sealant creates a waterproof barrier – when applied properly – that not only prevents moisture damage, but also contains fungicides that prevent the growth of mould in damp areas such as a bathroom.

The ideal temperature to apply silicone sealant is between 4°C and 45°C. Some special silicones can be applied between -40 to 55°C.

Soudal Fix all hybrid polymer sealants / adhesives can work convincingly well underwater. Their effectiveness may be slightly compromised, but this product still retains their properties and have good bond strength to substrates.

Soudal Fixall which is high tack product can be used for most of the vertical application but can’t be used for overhead tiles fixing due to limitation.

Silicones are not paintable. The paint will neither stick to the silicone itself nor to silicone-stained substrates. So, make sure you choose the right silicone color for your project and clean away all residue and stains before finishing.

GP silicones life is uncertain when used in exterior application since high concentration of acetic acid found in acetoxy silicone is highly corrosive. Also, it may cause discoloration in outdoor application.

Neutral cure silicone doesn’t create an acidic environment, it is the perfect solution for caulking materials that would otherwise be damaged by acetoxy sealant. Neutral cure silicone is better for exterior use because it is more weather resistant than its acetoxy counterpart.

No product is recommended to use after the expiry date as per ISO standards, as the shelf life of the product is limited to storage conditions.

For standard operating procedure, surface cleaning and sealant application, please refer to respective product technical data sheet.

Silicones are used in different application based on the formulation. The right silicone sealant to be chosen based on the substrate and the application. Silicones are used in construction, automotive, electronics and general manufacturing.

Sealant quantity for a joint gap depends on the depth and width of the joint. Please contact technical expert for more information.

We need to understand the surface energy of substrate and the sealant for better adhesion. It is always suggested to make a preliminary test before going for mass application.

The sealant is moisture curing and starts to cure after few minutes to a fully cured product by a weeks’ time based on the depth of the sealant applied. Curing also depends on temperature and humidity.

Skin over time is the measures of time between application and the formation of the skin as the outermost layer cures. As the skin develops, the applied adhesive or sealant rapidly loses its ability to bond to secondary substrates and is more difficult to tool.
Tack free time is when the surface of the sealant/adhesive ceases to be sticky and prevents “pickup” of dirt or debris that could otherwise discolor the exposed product.

It is always advised to wait at least 1 day to let the sealant dry before applying any paint.

Most silicones have an operating temperature from -60°C up to +230°C. There are special types of silicone which can endure an even greater range of temperatures. High temperature silicone rubber can be exposed to temperatures as high as +300°C.

The paintable sealant, if possess good weather resistant it can be used for outdoor application as well and it doesn’t make any difference.

The bead size can be calculated using depth and width of the joint. Please contact technical expert for more information.

Always make sure the application surface is well prepared before applying any sealant. Also make sure to use proper tooling method for better finish.

Backer rod can be used as backing material in most cases if the gap is larger then use PU foams to fill the gap followed by sealant for finishing.

Bonding is depending on the surface energy of substrate and the sealant/adhesive for better adhesion. It is always suggested to make a preliminary test on the substrate before application.

The sealant adhesion will be poor if sealant applied on wet surface for most cases. Hybrid sealant is one of the kinds which can be used on the wet surface and even under water.

Sealant properties are based on the formulation and the impact when exposed to climatic condition differs for different products. Please contact technical expert for more information.