Problems and Solutions Encountered in Polyurea Applications

Polyurea coating applications are preferred in many sectors due to their advantages such as rapid curing, high strength, and flexibility. However, some problems may arise due to incorrect application of these systems or incorrect material selection. The main problems include deficiencies in surface preparation, insufficient mixing ratios, and failure to control ambient temperature and humidity. These factors can cause the polyurea coating to fail to perform as expected, leading to adhesion problems and premature wear. Another important problem is the formation of bubbles or pinholes during application. These types of defects are more common in thick film applications and can negatively affect the waterproofing property of the coating. The cause of bubbles is usually moisture on the surface or air bubbles trapped by the polyurea. Pinholes, on the other hand, can occur if the applied polyurea layer is not thick enough or if small holes on the surface are not completely closed. In addition, color change and lack of UV resistance are among the problems encountered in polyurea applications. Especially in outdoor applications, polyurea coatings exposed to UV rays may change color or lose their properties over time. Therefore, the use of special UV-resistant formulations and regular maintenance are of great importance.

The success of a polyurea coating is directly proportional to its adhesion to the surface. Adhesion problems are usually caused by inadequate surface preparation, incorrect primer selection, or surface contamination. Ensuring that the surface is clean, dry, and properly roughened allows the polyurea coating to adhere firmly to the surface. During the surface preparation stage, oil, dirt, rust, and other residues should be removed, and sandblasting or chemical cleaning methods should be used if necessary. Primer selection is also critical for adhesion. A primer that is compatible with polyurea, adheres well to the surface, and allows the polyurea to adhere to it should be used. It is also important to apply the primer at the correct thickness and evenly. To prevent adhesion problems, the moisture content of the surface should be checked before application, and application should not be performed on damp surfaces. In addition, surface temperature and ambient temperature should be taken into account during application. Cold surfaces may prevent the polyurea from adhering sufficiently. By performing adhesion tests, the suitability of the surface should be confirmed before application.

Bubble and pinhole formation in polyurea applications can not only spoil the aesthetic appearance but also reduce the protective properties of the coating. To prevent bubbles, ensure that the surface is completely dry and use techniques that will prevent the formation of air bubbles on the surface during application. When using high viscosity polyurea systems, it can be difficult for air bubbles to rise to the surface. Therefore, lower viscosity and faster curing systems may be preferred. In addition, adjusting the gun angle and spray distance correctly during application can also reduce bubble formation. To prevent pinholes, ensure that the applied polyurea layer is thick enough. Thin layers may not cover small holes on the surface and may cause pinhole formation. The risk of pinhole formation can be reduced by applying multiple layers. It is important that each layer is applied evenly and homogeneously. In addition, a filler material can be used beforehand to reduce the roughness of the surface.

One of the most important problems encountered in outdoor applications of polyurea coatings is color change and UV resistance. Polyurea coatings exposed to UV rays for a long time may yellow, fade, or crack over time. Therefore, special UV-resistant formulations should be preferred for outdoor applications. To increase UV resistance, UV stabilizers and pigments are added to polyurea formulations. These additives reduce the harmful effects of UV rays on polyurea and protect the color and properties of the coating. It is also possible to apply a UV protective topcoat on top. This topcoat protects the polyurea from UV rays and extends its life. Regular maintenance is also important to prevent color change and UV resistance problems. Cleaning the coating surface and applying a UV protective polish periodically protects the coating's appearance and performance. Especially in regions with intense sunlight, the use of UV-resistant polyurea systems and regular maintenance are of great importance.