Powder Coating Application Problems & Solutions

Poor Charge or Low Film Build

Due to poor charging, Low Film thickness is observed due to this you will see orange peel & substrate especially in white, Ivory & yellow colours.

Cause of Problem	Solutions
The most common cause of these issues is poor grounding, as a good ground is essential for proper electrostatic charging. However, grounding is not the only factor. Incorrect gun settings can also contribute to the problem. Excessive powder flow and improper kV (kilovoltage) levels can negatively impact the quality of the application.	Ensure that a proper earthen ground is in place. Make sure all connecting parts are clean and free from contaminants. Regularly clean powder buildup from hooks to maintain effective grounding. Verify your kV levels and powder flow settings. Refer to the Technical Data Sheet or contact your supplier to confirm the correct parameters.

Poor Penetration of Powder into Corner Areas

Poor powder penetration into corners or recessed areas is often caused by a phenomenon known as the Faraday Cage effect. Due to the nature of electrostatics, the charged powder is naturally drawn to flat surfaces and edges, while being repelled from tight corners and recessed areas. As a result, these zones may receive insufficient coverage, leading to bare or undercoated sections on the part.

Cause of Problem	Solutions
Most powder coaters encounter the Faraday Cage effect, and while it can be difficult to manage, it’s important to understand what causes it. Several factors can contribute to this issue, including improper grounding, incorrect gun settings, insufficient powder flow, improper gun-to-part distance, a poor spray pattern, and using powder that is too fine. Addressing these variables can help improve powder penetration into recessed or complex geometries.	Methods to prevent Faraday Cage effect. Increase the powder flow rate to ensure more powder leaves the gun and reaches difficult areas. Adjust the gun-to-part distance to optimize coverage in recessed corners. Monitor the mix of virgin and reclaimed powder. Reclaimed powder tends to be finer and holds a weaker electrostatic charge, which can increase the risk of the Faraday Cage effect.

Cause of Problem

Solutions

Most powder coaters encounter the Faraday Cage effect, and while it can be difficult to manage, it’s important to understand what causes it. Several factors can contribute to this issue, including improper grounding, incorrect gun settings, insufficient powder flow, improper gun-to-part distance, a poor spray pattern, and using powder that is too fine. Addressing these variables can help improve powder penetration into recessed or complex geometries.

Methods to prevent Faraday Cage effect.

Increase the powder flow rate to ensure more powder leaves the gun and reaches difficult areas.

Adjust the gun-to-part distance to optimize coverage in recessed corners.

Monitor the mix of virgin and reclaimed powder. Reclaimed powder tends to be finer and holds a weaker electrostatic charge, which can increase the risk of the Faraday Cage effect.

Back Ionization

Each part can only hold a limited amount of electrostatic charge. When this limit is exceeded, the part begins to repel the charge rather than attract it. This phenomenon, known as back ionization, causes the powder coating to behave abnormally—often appearing raised or uneven in the affected areas.

Cause of Problem	Solutions
Poor grounding and using powder that is too fine can contribute to this application issue by forcing the part to accept more charge than it can handle or by continuing to apply powder after the part’s charge limit has been exceeded. The Faraday Cage effect can also play a role in this problem.	Ensure a good and secure grounding connection. Reduce your microamp and kV (kilovolt) settings. Decrease the powder flow rate.

Cause of Problem

Solutions

Poor grounding and using powder that is too fine can contribute to this application issue by forcing the part to accept more charge than it can handle or by continuing to apply powder after the part’s charge limit has been exceeded. The Faraday Cage effect can also play a role in this problem.

Ensure a good and secure grounding connection.
Reduce your microamp and kV (kilovolt) settings.
Decrease the powder flow rate.

Gun Spitting

When the gun spits out powder unevenly, it leads to inconsistent coating thickness and a poor-quality finish.

Cause of Problem	Solutions
One possible cause of this problem is excessive fluidization, meaning the powder flow from the gun has too much air and not a consistent air-to-powder mix. Powder buildup on the gun tip, electrode, or inside a longer hose can also cause spitting. Additionally, high humidity or moisture in the air may contribute to this issue.	Consult your equipment manufacturer to determine the ideal hose length for your powder coating system. Monitor and control air moisture levels to prevent issues caused by humidity.

Application Process For Metallic Finish Powder

Metallic powders can be more challenging to spray than solid colors, especially when there is a significant contrast between the base color and the metallic flakes. For most metallic applications, better results are achieved by lowering your kV and voltage settings. A typical range is between 60 and 75 volts, with the kV set between 25 and 35. Additionally, avoid applying the powder too quickly to ensure an even, smooth finish.