Media blasting plays a central role in preparing a surface for the powder coating process, by both cleaning the surface and applying texture. Here is a brief overview of media blasting, how it differs from sandblasting, and how it factors into the powder coating process.
What It Is
Like sandblasting, media blasting is a method for preparing a surface for powder coating that involves removing oils, grease, dirt, paint, rust, corrosion, and other surface contaminants from metals. It is highly important to remove these substances from a surface before powder coating because these are things that will work to contaminate a powder coating upon contact, thus interfering with the powder coating process and weakening the bond between the powder and the metal. Media blasting, like sandblasting, works to remove these contaminants by using a fine abrasive material such as baking soda, glass, beads, walnut, green diamond, and corn cob to clean a metal surface of any unwanted surface materials and etch it.
Media blasting involves propelling very small bits of an abrasive substance at extremely high speeds with an air-powered pressure gun to clean and etch a metal surface. There are various types of pressure guns that serve this purpose, but while the physics between them might differ, the principles behind them remain the same: propelling an abrasive material onto a surface to clean and rid it of any rust, paint, or other unwanted materials, all the while preparing it for powder coating by giving it a slight texture.
Media blasting is more effective than sandblasting for preparing certain surfaces, such as thin metals that could be warped during the sandblasting process. Media blasting involves the use of a wide variety of abrasive materials, making for a truly customizable surface profile and finish. Beads, for example, can be used on surfaces that might be damaged very easily during sandblasting, and larger beads can be chosen to make for deeper texture in the resulting surface profile.
The etching or scratching of the surface created by media blasting makes for a better adhesion of a powder coating, making it stick much better than it would have had the surface remained completely smooth. Without a textured surface profile, a powder coating could simply peel off of a surface. While sandpaper could theoretically provide the same etching and surface profile that media blasting could, media blasting is able to reach place that sandpaper simply can’t, and it creates a uniform, textured finish all over that makes for a perfectly even application of powder coating. Media blasting also rids a surface of any contaminants that would prevent a powder coating from adhering correctly.
Media blasting can also be environmentally friendly, as the materials used can be recycled several times.