When it comes to protecting metal parts and pieces, it’s hard to beat the dependability of powder coating. What began as a fad common with industrial materials in the 1940s has quickly morphed into a 15% market share of the preferred method of industrial finishing across the globe today.
But what role does powder coating have on today’s automotive market – specifically, protecting wheels and aftermarket parts on our daily drivers? How good is it at protecting a top coat on wheels, or making them easier to clean? Is it just as good as automotive paint with a ceramic coating?
That’s what we’re going to discuss today. In the information below, we’ll provide a definitive guide addressing the truth about powder coating. We’ll explain what powder coating is, where it started, how it works, and how many car owners use it today to enhance their wheels or aftermarket add-ons.
What is Powder Coating?
History of powder coating
Powder coating was developed in the 1940s, where volatile organic compounds or polymers (also called macromolecule) were spayed in a powder form on a metallic base. The industry grew significantly in the 1960s due to the growing ecology movement and the introduction of an electrostatic spray powder coating process, which electrically charged powder particles that would infuse onto a grounded material.
Procedure:
The powder particles stick to metal due to a process called electrostatic attraction. Once fused onto metal, the coated product is then inserted into an oven, melted, and then bonds once cured. The fact that paint could now be sprayed onto metallic surfaces without polyurethane or VOC’s not only makes it an environmentally friendly option to traditional liquid paints and clear coat protection but provides extra strength.
Used as protective or decorative finish
Today, powder coating is used as a protective or decorative finish used in agriculture, military applications, boating & marine supplies, electronics, and of course, the automotive industry.
It has been one of the most cost-effective methods of treating bare metal, as it is relatively cheap. It’s often assumed that powder coating is only applied to metals. However, it can be used on both plastics and medium-density fiberboard (MDF).
How is Powder Coating Used in the Automotive Industry?
Used for protection
While some off-road or performance vehicles use powder coating to protect bare metal chassis or roll cages, it’s rare to find body panels coated due to the excessive cost and weight of powder-coated materials. Many auto applications use powder coats on wheels, engine parts, or undercarriage and suspension components.
Increases resistance to contaminants
When automotive parts are coated through this method, they become much more resistant to damage due to exposure to moisture, chemicals, UV light, chemicals, and impact. This is a major reason why you’ll find most performance wheels (especially those used in off-road applications) powder coated.
Reduces risk of wear and tear
Powder coating also reduces the risk of abrasions, scratches, chipping, fading, and other common wear and tear issues found with wet paint. Manufacturers of aftermarket parts also love using this method due to the lack of chemical waste – unlike spray paints that use chemicals (thinners and VOCs) that require expensive waste disposal methods that must comply with US EPA regulations.
How is Powder Coating Applied?
The process of powder coating services to automotive parts follows four-general steps.
- Picking the right powder coating material
- Prepping the parts being coated
- Applying the powder coating via an electrostatic charge
- Curing
1. Choosing the Right Powder Coating
Specific powder coating for each material
Another common assumption about powder coating is that it’s a one-size-fits-all type of process. The truth is – every material has a specific powder coating formulation that is used for optimal results. However, there are two general types of powder coating, a thermoplastic or thermoset polymer.
Thermoplastic vs Thermoset coating
The primary difference between these two is the ability to reverse or remove the coating. Thermoplastic coatings can be removed or melted again, while thermoset is a permanent application.
Most thermoset powder coatings are used for electronics and appliances since they withstand extremely high heats. Thermoset is also used to reinforce the structural integrity of a product. Thermoplastic, on the other hand, is a blend of flexibility and strength.
Within these two primary powder coating types are multiple grades of coating that are used for specific metal or plastic types. Different grades are used to produce individual textures, colors, or protection levels.
2. Prepping the Product for Powder Coating
Once the right powder coating has been selected, the next phase is prep work. Like any other coating, the quality of prep work can significantly impact the overall application results. Professional powder coaters usually complete three steps to prep metal or plastic materials.
Bead or Abrasive Blasting
The first step is to remove any contaminants on the material being coated. On metals, getting rid of rust, mill debris, or other foreign materials is completed by bead or abrasive sandblasting. In this process, tiny particles of silica or sand are blasted at high air pressure until the contaminants are fully removed.
Fine Grinding of Sharp Edges
The second phase of prep work (especially with rims or wheels) is to manually remove any sharp edges or burrs on the product being coated. During the electrolysis phase of coating, the powder sometimes collects or builds upon sharp or pronounced edges. To ensure a smooth and even coating, the powder coater will use a polishing wheel or cutting wheel to smooth out the product.
Soaking in Acetone
Once the product is stripped to bare metal, the next step in the prep work is to remove any remaining gunk or grime. This is usually accomplished by soaking the product in acetone or other chemical baths. Final cleaning in a steam bath removes the chemical cleaner.
3. Applying the Powder Coating
This is where the fun starts. Applying a powder coating involves the use of highly specialized equipment, starting with the spray gun or a compressed air sprayer that will electrostatically charge the powder which will be infused into a grounded metallic part.
This video is probably the best example of how powder coating is completed on a set of aftermarket wheels. As the process is always customized for the specific material type, it’s best to review this video to gain a big-picture perspective as to how it’s accomplished.
4. Curing the Coated Product
The final step is to cure the powder coated product.
Use of large, industrial kiln
Similar to curing a ceramic pot, the process of curing powder coating involves the use of a large, industrial kiln or oven. In most cases, the object is heated to 350° to 375° F (175° to 190° C) for about 10 to 15 minutes.
Set to cool down
Of course, like the application of specific grades of powder coating, each type also has individual curing procedures. Once the initial ‘cooking’ has been completed, the product is allowed to cool for a minimum of a few hours at room temperature.
Pros of Powder Coating
Like any other coating or protection product, there are some pros and cons that should be considered if powder coating your wheels, or other performance parts is on your radar.
Some of the pros of powder coating include:
Durability
Once the powder coating has cured, it’s one of the hardest materials out there. It’s a great product for protecting the material from scratches, dings, and damage. However, it’s not always the longest-lasting products, nor is it bulletproof.
Environmentally Friendly
Since powder coating is sans chemical liquids, it’s a product that can be used and reused. This means that there are very little wasted materials, there are no VOC’s or chemical emissions upon application.
Cost-Effective
For the process to involve very little wasted material, it’s one of the most cost-effective ways of protecting mechanical components. However, this is for industrial applications. DIY’ers might find it to be more expensive than other DIY applications of paint protection products.
Cons of Powder Coating
Quality of the Coating
Sometimes, powders are cross-contaminated at the location of installation. When this happens, it can impact the quality of the coating, specifically the color or appearance. Due to this fact, it’s best to do your homework and work with a professional powder coating expert.
Weight and Thickness
Powder coating is not the best option if weight conservation is important for you. It’s rather heavy and applies thick. It also does not apply smoothly. It’s usually a bumpy surface when completed.
Not Hydrophobic
Many people believe that powder coating is great to use on wheels because it makes it easier to clean. That’s another myth. Since it’s thick, it tends to allow items like brake dust and road grime to stick. It’s better than non-protection products, but there are better solutions if this is your goal.
Investment Capital
While it’s possible to learn how to powder coat, the start-up costs for special equipment, installation locations, and proper ventilation, can exceed thousands of dollars. The quality of your equipment will impact the quality of the end product.
Is there a Better Solution for Keeping Wheels Cleaner?
Some people use powder coating to protect their wheels, exhaust tips, or other exposed performance parts from exposure to salt, road grime, chemicals, dirt, and debris. If this is your goal, you might want to consider using a high-quality and easier to apply a product like a DIY ceramic coating.
Ceramic coatings can be used for protection
It’s often assumed that ceramic coatings can only be used on clear coated paint. But, like the assumption about powder coating only used on metal, this is another myth. In fact, ceramic coatings like Armor Shield IX can be used on alloy wheels, magnesium, steel, and ceramic wheels. They can also be used on chrome and vinyl wrapped surfaces.
Benefits of using ceramic coating
Unlike powder coating, a ceramic coating is exceptionally hydrophobic, making brake dust easy to remove. It also protects against salt, mag chloride, or other de-icing products.
Wrapping it Up
Powder coating has come a long way since it’s early applications of in the 1940s. While powder coatings are exceptional for protecting industrial equipment, the introduction of easy to install DIY ceramic coatings have introduced a better alternative to powder coating on performance products like custom wheels for example.
Ceramic coatings like Armor Shield IX are just as environmentally friendly, hold up against exposure to daily driving, and will not dull or change the surface appearance of your expensive OEM or aftermarket wheels. If protection is your ultimate goal, ceramic coatings offer an easier, more affordable, and a longer-lasting option to powder coating.
Can you tell me what product can be applied to metal to fill and smooth out the surface before powder coating that can withstand the temperature used when powder coating?
Something like Bondi used before paint.
Thanks,
Joe
Hi Joe!
I haven’t tried your particular scenario before but I would think the low cost of a putty kit might do the trick. Of course, check with the specific manufacturer to find out the temperature tolerance of the product.