How Moisture Impacts Powder Coatings and How to Control It
High humidity can cause significant issues for powder coaters – from clumping powder to equipment damage and increased maintenance on parts. Let’s explore how moisture impacts powder coatings, plus how to detect issues and control moisture on your line.
How Moisture and Humidity Impact Powder Coatings
High humidity can wreak havoc on powder coating operations, impacting powder flow, affecting application quality, and even threatening your equipment’s longevity. Understanding these effects is key to maintaining efficiency and product quality.
Affects of Moisture on Powder Coats
Moisture can cause numerous issues in a powder coating operation, including:
- Poor Adhesion: Moisture can cause powder particles to clump together, leading to uneven application and poor adhesion to the substrate.
- Surface Defects: Issues such as pinholes, cratering, and fisheyes can appear when moisture or oils are trapped in the coating, or between the coating and the substrate.
- Inconsistent Finish: Moisture can create an uneven or blotchy appearance, reducing the quality and aesthetics of the final product.
- Equipment Damage: High moisture content will wear gun parts sooner. This is called “Impact Fusion.”
Signs of Moisture-related Issues
There are ways to detect if you’re facing moisture-related issues. Powder clumping shows that your powder is not flowing smoothly. This can be an early sign of moisture buildup in your hopper, causing a surge in powder deployed from the spray gun during application – affecting mil thickness and creating an uneven finish. Surface irregularities like craters or bubbles are also often indicators of moisture contamination during the application process.
Solutions
There are several solutions to control moisture in your powder coating process:
- Climate Control: Your storage area should be cool, dry and free of air-borne contaminants. Proper ventilation and dehumidification in your facility can help maintain optimal humidity levels, preventing moisture from affecting the powder.
- Powder Storage: Storing powder in a dry, temperature-controlled area is crucial for maintaining its integrity. Ideal storage conditions range from 50° F to 80° F and 40% to 60% relative humidity.
- Equipment Maintenance: Ensure that compressed air systems and other equipment are free of moisture, oils and other contaminants by using air dryers or filters.
How Sherwin-Williams Can Help
At Sherwin-Williams, our Technical Service Representatives are experts in identifying and solving moisture-related issues. They can:
- Conduct on-site assessments to detect and troubleshoot moisture problems.
- Recommend solutions for humidity control, powder storage and equipment optimization.
- Work with your team to ensure smooth, moisture-free powder coating operations.
By partnering with Sherwin-Williams, you not only gain access to world-class quality coatings but also dedicated local technical support. Meaning one team to help you solve all your coatings challenges, from start to finish.
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