Troubleshooting Bubbling in Coatings

Troubleshooting Bubbling in Coatings

Bubbling in a flooring system consisting of a polyurea base coat, vinyl chips, and a polyaspartic topcoat can be caused by several factors. Here are some common reasons for such failures:

1. Moisture Vapor Emission: If there is moisture present in the concrete substrate, it can cause bubbles or blisters in the coating. Polyurea and polyaspartic coatings are very sensitive to moisture. A moisture vapor emission test should be conducted prior to application to ensure the substrate is within acceptable limits.
2. Substrate Preparation: Inadequate surface preparation is a frequent cause of coating failures. The concrete surface must be properly cleaned, profiled, and dried. Contaminants such as oil, grease, dust, or previous coatings can prevent proper adhesion, leading to bubbling.
3. Application Conditions: Environmental factors like temperature and humidity play a crucial role in the curing process of polyurea and polyaspartic coatings. If the conditions are not within the manufacturer’s recommended ranges, it can result in improper curing and bubbling.
4. Mixing and Application Errors: Incorrect mixing ratios or inadequate mixing of the components can lead to improper curing. Additionally, applying the coatings too thickly or too thinly can cause issues. Each layer should be applied according to the manufacturer’s specifications.
5. Outgassing: When the substrate releases trapped air or moisture as it warms up, it can cause bubbles in the coating. This can happen if the coating is applied when the concrete is cooler and then warms up later, releasing air or moisture.
6. Incompatible Materials: Ensure that the polyurea base coat, vinyl chips, and polyaspartic topcoat are compatible and from the same manufacturer or are recommended to be used together. Incompatibility can lead to poor adhesion and bubbling.

To address the issue, the contractor should:

1. Test for Moisture: Conduct moisture tests on the substrate to ensure it is within acceptable limits for the coating system.
2. Review Surface Preparation: Verify that the substrate was properly prepared according to industry standards and manufacturer’s guidelines.
3. Check Environmental Conditions: Ensure that the temperature and humidity levels were within the recommended range during application and curing.
4. Follow Manufacturer Instructions: Double-check the mixing ratios, pot life, and application techniques recommended by the manufacturer.
5. Inspect for Outgassing: Consider the timing of the application in relation to the temperature changes in the environment.

By systematically addressing these potential issues, the contractor can identify and rectify the cause of the bubbling in the floor coating system.