Q. We are setting up a new line to produce power transformers and are trying to determine the best way to get paint onto the cooling radiators. I maintain that we should spray paint the radiators. The distance between two fins is only 50 mm. Is spray painting the best option, and if so, what type of spray guns or special nozzles do you recommend? V.J.
A. To paint the radiator fins you described, you can use an airless or air spray gun. Don’t use an electrostatic spray gun because, depending on the configuration of the fins, the Faraday Cage effect may result in areas of poor coverage. Again, depending on the configuration of the fins, you may find it convenient to use lance spray nozzles which are mounted on the ends of lances that attach to both types of spray guns. The nozzles are designed to spray in one direction or in a 360-degree pattern.
An alternative method for coating odd-shaped objects is flow coating. My company used this method to paint very small and very large power transformers. The large ones were painted in a booth manually using a device similar to a garden hose. The small ones were painted on a conveyorized line using an automatic flow coater in an enclosure. In both cases, the paint was formulated to coat the surfaces at a specific film thickness. After coating, the excess paint dripped or flowed into a recovery tank and was recycled back to the coating heads. Paint and painting equipment suppliers can be found at PFOnline.com.