What is Powder Coating?
First I will cover the very basics of what powder coating is.
Powder coating is the process of applying a paint in the form of powder. Regular liquid type paints are pigments and binders suspended in solvents. Powder coating is solvent free so you are just using the dry pigments and binders. Once the powder is sprayed on your work piece, it must be baked from 350 to 400 degrees F for 10-20 minutes. Each powder has its own specific curing schedule and you should always that schedule when dealing with that particular powder. When the powder is heated, it melts into a liquid, connects together, cures, and once cooled, is dried to a hard, beautiful finish.
Generally, when powder coating metal, the powder is given a positive charge when it leaves the gun and it is attracted to a grounded workpiece. Once the piece is fully and evenly coated, you carefully transfer it to an oven that can heat the powder to the specified temperature. The powder will melt, flow out, and then cure during this process. The usual specification for the piece is anywhere from 350 degrees F for 20 minutes to 400 degrees F for 10 minutes.
Powder Coating metal serves a couple of purposes. The functional purpose is that it provides a barrier between the metal and the oxygen around it protecting it from corrosion. When it comes to iron or steel, this is very important to prevent rust. . However, if the powder coating is scratched, or chipped down to the bare metal underneath, rust can start in this spot. Media blasting a part before powder coating will provide a profile for the powder to adhere tightly to the part, this helps reduce the spread of rust underneath the powder coating after it is scratched and keeps it centralized to just the scratched area. You can read more on creating a profile here.
The aesthetic purpose of powder coat is that you can choose from an almost unlimited amount of colors, textures, gloss-levels, ect. Powder coat colors can be applied in multiple coats to achieve even more unique finishes.
To learn the very basic steps of the powder coating process, check out my Step-by-Step Tutorial.