1) Cleaning and surface preparation of the item you want coated
2) Spray application of the coating material
3) Heated curing of the part
Step One: Surface Preparation
No matter what you decide to coat, the surface of the part must be clean. Without proper surface preparation, any type of soil (oils, polymers, dirt, metal bits, soaps, etc.) left on a part will cause problems. Bubbling, streaking, flaking and reduced durability are just a few of the adverse effects – and all are avoidable by proper cleaning.
Pretreament equipment is used to help clean your part before you start coating. Common pretreatment equipment includes wash stations which are staged areas where you can wash your part. Other pretreatment options include steam units, dip tanks, and blasting stations.
It’s important enough to repeat it: Regardless of the part to be coated, large or small, your parts must be cleaned thoroughly for the powder media to work properly. For more on pretreatment, go here.
Step Two: Spraying the Powder
The powder is applied with a specially designed powder spray gun. The powder spray gun applies an electrosatic charge to the powder which allows the powder to stick to the part.
Not all of the powder you spray will stick to the part, and if the air isn’t clean other stuff will stick (giving you the same problems as if you hadn’t cleaned it). To make sure this doesn’t happen, powder is almost always sprayed inside a powder spray booth or in front of a powder spray wall. These are enclosures designed for optimum airflow and ventilation to make sure the air is clean and the excess powder stays inside the booth (and not all over the shop space). Want to know more about powder spray guns and spray booths? Click here.
Step Three: Curing the Powder
The last stage before your part is completely powder coated is curing. The coated part is placed inside a powder coating oven and cured at a constant temperature ( between 325-425 degrees F for most powder). The powder melts and bonds together, forming an extremely durable and resilient coat. And that’s it! From cleaning to coating to curing, you now have a finished, powder coated part that will last a very long time. Need more info on powder coating ovens? Click here.
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