Water resistant coating – watertight solution
Water resistance is a characteristic expected of many consumer goods, from electronics to shoes and fabrics. It is also required from industrial machinery and architectural structures. A water resistant coating is the most common solution for improving or creating water resistance in industrial and architectural projects. Water resistant coatings form a barrier between the substrate and its environment; depending on the water resistance treatment, the barrier can be impermeable to both water and water vapour.
In this article we will describe the different water resistant coating systems, outline the options for different industrial and architectural applications, and discuss the most common issues linked to water resistant treatment of surfaces.
The 3 definitions of water resistant coating
Though the terms ‘water resistant’, ‘water repellent’ and ‘waterproof’ are often used interchangeably, they actually describe different degrees of water resistance. Water resistant coatings can be classified by their degree of water resistance as follows:
- Waterproof: An almost 100% watertight solution, these coating systems are absolutely impermeable to water.
- Water repellent: Higher resistance than ‘water resistant’, yet also not completely impermeable to water. Often refers to nano- or fluoropolymer coatings which literally repel water.
- Water resistant: Usually the lowest degree of water resistance. Able to resist water penetration to a certain extent, but not entirely – in most cases a ‘water resistant’ product cannot be completely submerged without problems. ‘Water resistant’ is also the general term for water protective coatings.
Despite the difference between waterproof and water resistant, consumer products may still be labeled waterproof when they are only resistant, and vice versa. But these are descriptions that can apply to more than just coating. When choosing a coating, you should always check the datasheets and instructions.
4 coatings that function as water resistant treatment
Waterproofing products are as various as waterproofing projects. However, not every water resistant coating suits all situations; like with all coating projects, you need to take into account the intended substrate, use, and environment of the coating, as well as that the required degree of water resistance. For example, a water resistant coating for fabric needs to be invisible, water resistant coating for electronics must be applicable in thin films, and steel requires an impermeable barrier to protect from corrosion. On the other hand, a waterproof wall paint never is 100% watertight, due to the fact that it needs to remain breathable. Here are four of the most common water resistant coating solutions:
1. Surface coating technologies for watertight pre-treatment
What it is:The treatment of a metal surface with another metal in processes like galvanisation and anodisation is seen as an effective corrosion protection method in certain environments. These processes also provide water resistance, to a certain extent, by covering the original metal substrate. However, this is often not sufficient, so to conform to tougher waterproofing requirements it is topped with a resin or fluoropolymer coating.
Properties: Corrosion resistance, limited water resistance.
Uses: Steel structures and products, in tougher environments as pretreatment with a further topcoat.
2. Nanoscale coatings for innovative water protection
What it is: The most innovative water resistant coatings are based on nanotechnology, and do not just coat a substrate but actually bond with it, forming a layer that is no longer separate. The use of these coatings, especially in waterproofing industrial structures, is increasing and the technology keeps developing. Nanotechnology coatings also exist as water resistant spray treatments that are available for consumers to apply at home.
Properties: Thin and invisible coating. Due to poor abrasion resistance, they require frequent reapplication.
Uses: Touchscreens and displays, small surfaces at home (e.g. windows and shower cubicles), protecting wooden floors from water.
3. 100% watertight 2K resin coatings
What it is:Two component resin coatings such as polyurethanes and epoxies belong to the most durable water resistant coatings group. Such a coating is almost always a good idea, and there are many different types which can be further modified to meet specific requirements.
Properties: Extremely durable, impact and abrasion resistant, watertight, chemical resistant and many more beneficial properties depending on the type of resin coating. Usually a high solids coating that adds to the weight and size of the coated object.
Uses: Pools, vertical and horizontal architectural structures (from bathrooms to offshore wind turbines), cargo and storage tanks, machinery and automotive parts.
4. Fluoropolymers for where a efficient water resistance
What it is: Fluoropolymer coatings are known for their low coefficient of friction and use as lubricants. The most common of these are FEP and PTFE coatings such as Xylan and Teflon which are almost impermeable to water. Fluoropolymers are also the most common type of Durable Water Repellent (DWR) coatings which are applied to fabrics as waterproof yet breathable coatings.
Properties: Insulating, impermeable to gases and water, resistant to chemicals, UV radiation, contamination, chalking and corrosion. Applied as a thick film; affects weight and size.
Uses: Consumer goods, industrial machinery, automotive parts, insulation of wiring, fabrics.
Facts to be aware of when looking for a water resistant coating solution
No matter which water resistant treatment you choose, you should keep the following in mind:
- Standards: Water resistant coating for electronics, fabrics and other consumer goods is not regulated by any British Standards. Water resistance is not required and usually not measured.
- Product names: The product names may be misleading – make sure you read the fine print and check whether waterproof and water resistant mean what they say.
- Application and warranty: When it comes to architectural water resistant coatings, rely on a professional, certified contractor whose work quality is guaranteed by a warranty and certification. Water resistant masonry paint, for example, is usually given a 7 year guarantee when applied correctly.
If you are looking for more information on water resistant coating for a specific application, do not hesitate to contact us. Our coating experts are happy to answer any questions you may have. Together with our partners we can also draw up a tailored quote for your project, application, or product. Get in touch via email or through the “Request a quote” button below and let us connect you with the coating solution for your project.