Polyurethane paint

What is polyurethane paint?

Polyurethane paint is an exceptionally durable and damage-resistant solution used across a variety of industries. Its properties make it ideal for surfaces exposed to heavy use, weather conditions, and chemicals. It boasts excellent adhesion to various materials, such as metal, concrete, and wood, making it versatile and widely used in construction, industry, and the automotive industry.

Composition and properties of polyurethane paints

Polyurethane paints are two-component, meaning they consist of a base and a hardener. When mixed, a chemical reaction occurs, giving the coating exceptional hardness and resistance. The key properties of polyurethane paints include:

• High mechanical resistance – protects the surface against abrasion and impact.
• Chemical resistance – works great in places exposed to oils, fuels, detergents, and some acids and bases.
• Resistance to UV radiation – does not turn yellow or lose color when exposed to sunlight.
• Moisture resistance – ideal for use outdoors and in rooms with high humidity.
• Excellent adhesion – can be applied to metal, concrete, wood and other materials after using appropriate primers.

Main applications of polyurethane paints

Polyurethane paint is used in many industries. Here are its most common applications:

• Construction – painting of concrete floors, facades and roofs.
• Automotive – protecting vehicle bodies and rims against damage.
• Industry – covering machines and devices requiring a resistant coating.
• Furniture and wood – painting wooden elements.
• Yachts and boats – hull protection against water and sea salt.

Advantages of using polyurethane paint

Polyurethane paint is very popular due to its advantages, which include:

• Long-lasting surface protection – does not require frequent renewal.
• Resistance to harsh weather conditions – ideal for outdoor use, thanks to its full resistance to UV rays, rain, frost, and acid rain.
• Wide range of colors – the color can be adjusted to individual needs thanks to tinting in any color from the RAL palette.
• Easy to apply – available in a variety of forms, depending on the application. Can be applied by roller, brush, or spray.

What surfaces can be painted with polyurethane paint?

Polyurethane paint has versatile applications and can be used to cover:

• Metal – protects against corrosion and mechanical damage. Polyurethane paints are most often used as primers, primer-enamels, or anti-corrosion enamels. Examples include Krypton ProLine Silver TC, Krypton ProLine PU Al PRIMER , and Telpur S210 .
• Concrete – creates a durable protective coating on floors and walls. With the appropriate primer, it can be applied to dry or wet concrete, or after strengthening with an epoxy primer. Recommended primers include Epoxol® Primer , Epoxol® Primer SF-P , or Neopox® Primer WS, depending on the moisture content and substrate quality. Polyurethane paints designed for painting concrete include Neodur® Special or Troken Floor PUR WB-C .
• Wood – adds aesthetic appeal and increases moisture resistance. For clear protection, you can use a polyurethane varnish from the Neodur® Varnish . For colored wood protection, Neodur® Special is recommended. However, it's worth remembering that these polyurethane paints are only suitable for hardwoods.
• Roofing felt – a polyurethane paint with waterproofing properties, such as Neoproof® PU W-40 or Neoproof® PU Fast-30, adheres perfectly to bituminous substrates (roofing felt) after proper priming. Applied to roofs, it protects against leaks for 10 to 20 years, during which time it reduces the temperature of the roof and the rooms directly beneath it by up to several degrees.
• Plastics Neodur® Special or Neodur® Pool are most commonly used, as they adhere perfectly to polyester substrates.

How to prepare a surface for painting with polyurethane paint?

Surface preparation is a key step in ensuring the durability of the coating. The process involves several steps:

1. Cleaning the surface 

It's essential to remove all dirt, dust, grease, and old paint layers that don't adhere well. For metal, it's worth using a degreaser and thoroughly washing the concrete. If the concrete surface is oily, it's also worth degreasing. Sulfanol A or Emulsol . If a waterproofing polyurethane paint is being applied, for example, to roofing felt, it may also be crucial to use a fungicide called GrzyboStop to clean the roofing felt surface.

2. Grinding and filling gaps

Uneven surfaces or those covered with old paint should be sanded to improve the adhesion of the new coat. Before applying polyurethane paint to concrete, it's a good idea to sand the surface to increase the substrate's absorbency. If concrete or bituminous substrates, such as felt, have any gaps, they must be filled.

For concrete substrates, epoxy repair compounds such as Epoxol® Putty , Epoxol® Liquid , Epoxol® Primer SF-P mixed with fine quartz sand, or the polyurea compound Neodur® FT Putty . Felt substrates, on the other hand, often have various types of bubbles, which indicate trapped moisture. In such cases, it is recommended to cut them open and fill them with a flexible repair compound, such as Jointex® .

3. Priming

Some surfaces, especially metal, concrete, and bituminous surfaces, require the use of a suitable primer to improve the adhesion of polyurethane paint. For anti-corrosion protection, primers that protect the substrate against corrosion are used, such as Neopox® Primer 815 , Neotex® Metal Primer , or Telpox P100 .

For concrete substrates, primers used include:

• Epoxol® Primer – a solvent-based epoxy primer that penetrates concrete pores while strengthening it. Recommended for dry, poor-quality substrates.
• Epoxol® Primer SF-P – a solvent-free epoxy primer that seals the absorbency of the substrate. Additionally, it can be mixed with quartz sand to create a so-called construction resin, which allows for easy priming and filling of gaps.
• Neopox® Primer WS – a solvent-free epoxy primer for damp substrates. It can be used at very high surface humidity levels (<90%), and at the appropriate thickness can serve as a vapor barrier.

For bituminous substrates such as roofing felt, it is recommended to use Revinex® .

How to apply polyurethane paint?

The process of applying polyurethane paint depends on the type of surface and the method chosen. It can be applied:

• Roller or brush – a good solution for smaller surfaces and details.
• Pneumatic spraying – allows for even coverage of large surfaces.