How to Apply Moisture Cured Urethanes: Tips and Tricks for Success

Moisture cured urethanes have become a popular choice for coating and sealing applications due to their excellent durability, chemical resistance, and weathering capabilities. They are commonly used in industrial settings for flooring, roofing, and concrete protection, as well as in automotive and marine applications. However, applying moisture-cured urethanes can be challenging due to their unique curing process, which relies on moisture in the air. This can lead to variations in curing times and quality, making it important to follow certain tips and tricks to ensure a successful application. To help you achieve success when applying moisture cured urethanes, here are some tips and tricks to keep in mind: 

Prepare the Surface Properly

Proper surface preparation is essential for achieving a good bond between the moisture cured urethane and the substrate. Any contaminants on the surface can cause adhesion issues, leading to failure of the coating or sealant. The surface should be cleaned using an appropriate cleaner, and any loose or flaking coatings should be removed. Sanding the surface will create a good mechanical bond for the new coating to adhere to.

Use the Right Equipment

Moisture cured urethanes require specialised equipment for application, and it's important to choose the right equipment for the job. Airless spray equipment is the most common method used for applying moisture cured urethanes, but it's important to choose a tip size that is appropriate for the viscosity of the material. The equipment should also be clean and properly maintained to avoid any issues during application.

Control the Environment

Moisture cured urethanes cure by reacting with moisture in the air, so it's important to control the environment during application to ensure proper curing. The temperature and humidity of the environment can affect the cure time and quality, so it's important to monitor and control these factors. The ideal temperature range for application is usually between 50°F and 90°F, with a humidity range of 30% to 80%.

Apply the Material in Thin Coats

Applying moisture cured urethanes in thin coats is important to ensure proper curing and adhesion. Thick coats can trap moisture, leading to poor curing and adhesion. Multiple thin coats are also more effective than one thick coat because it allows the material to cure properly between coats. It's important to follow the manufacturer's instructions regarding coat thickness and application rate.

Allow Sufficient Drying Time

Moisture cured urethanes require sufficient drying time between coats and before the surface can be exposed to traffic or other stresses. The drying time can vary depending on the temperature, humidity, and thickness of the coat applied. It's important to follow the manufacturer's instructions regarding drying time to ensure the best results. Touching the surface too soon can lead to damage, while waiting too long can cause adhesion issues.

Take Safety Precautions

Moisture cured urethanes can be hazardous to your health if proper safety precautions are not taken. It's important to wear protective clothing, gloves, and a respirator when applying the material. The application area should also be well-ventilated to avoid inhaling any fumes. The material should be stored and disposed of properly to avoid any environmental issues.

By following these tips and tricks, you can achieve a successful application of moisture cured urethanes that provides long-lasting durability and protection. Proper surface preparation, equipment selection, environment control, coating application, and safety precautions are key to achieving the best results.