Powder coating provides a very durable form of metal painting that doesn't require as much maintenance as enamel-based paint. This is because the paint isn't applied as a liquid; powder coating is attached with electricity to a metal part and then baked on. The oven process solidifies the paint, creating a thick, tough layer of paint that takes quite a bit to scratch, chip or flake.
Preparation
Before an automotive body part or metal piece can be painted with powder coat, it needs to be prepared. Only metal parts can be painted; the baking process would melt or warp wood and plastic. The preparation process essentially involves stripping the part of all contaminants or previous paint. Sandblasting or media-blasting tend to be the methods of choice given the bare metal results produced. However, acid baths provide an alternative means of stripping metal bare.
Selective Painting
To make sure functional areas of a metal are not painted, the owner needs to tape these off. These areas include sockets, threads, screws, joints and similar parts of the metal where the paint would render them useless when reconnected again. Later on, the painter should cover these marked areas with rubber cement. The rubber cement fends off the paint powder but dissipates in the baking process, leaving the covered metal area clean.
Painting
When the part is ready for painting, it is hung on a rack and painted with a spray gun that is electrostatically charged. Using powder coat powder of the color desired, the painter then sprays the powder coat paint onto the part. The powder adheres to the metal part because of the static electricity charge. The metal part is then ready for the baking process when completely painted.
Baking and Curing
The painted part is then transported on the same metal rack into the baking oven. Inside, the heat temperature is raised to 160 to 210 degrees Celsius to initiate the melting process. The powder coat paint begins to break down and liquify into a smooth coat on the metal. The heat bakes the paint so that it bonds with the metal surface. The heat is then gradually turned down by the painter. The part is removed from the oven once the curing process is complete.
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