Coating complex part geometries can be very challenging due to the Faraday cage effect. However, with the proper set up, right equipment, and correct application technique, even tough Faraday cage areas can be successfully powder coated.
The Faraday cage effect can be overcome in a number of ways:
- Making sure the part is properly grounded: ungrounded parts have more severe Faraday issue
- Control humidity in the environment: below 40% relative humidity will increase the Faraday effect
- Adjust airflow velocity to deliver the powder inside a recess but not excessively preventing powder transfer
- Adjust gun voltage to reduce the charge on the powder particle: highly charged particles are more difficult to drive into the recessed areas and are more easily attracted to the flat surfaces.
- Change spraying angles: approach recess at an obtuse angel
- Use a slotted spray gun tip to concentrate spray: selecting a different nozzle for the gun to slow the powder velocity can be very helpful in coating recessed areas
- If all else fails, a tribo-charging (frictional charging) gun can be used to coat the most difficult Faraday areas, as they don’t have electrostatic field lines that cause the Faraday problems
- Finally, operator coating technique is very important: a well-trained operator will help ensure tough Faraday cage areas will be successfully powder coated
For more information on the Faraday cage effect, read TCI's Troubleshooting Guide.
Or contact us today to speak with one of our professional service technicians. We can help you with Faraday Cage questions or any of your powder coating needs.