Powder coating is a popular method for finishing metal, but that isn’t the only use for it. The benefits of powder coating, such as high-quality decorative finishes, durability, and various color or texture options, can apply to a variety of materials.
You can reap the performance and aesthetic benefits of this popular dry-finishing process by understanding what material can be powder-coated.
What are the Requirements for Powder Coating?
The main requirement for powder coating is the material’s ability to withstand extreme temperatures. The powder coating process can reach temperatures of 400 degrees F or higher, which can cause some materials to melt.
Powder coatings are based on polymer resins, which are combined with leveling agents, pigments, curatives, and various other ingredients. These are mixed and ground into a fine, smooth powder with the texture of flour. Once mixed, a process called electrostatic spray deposition is used to apply the powder coating. A spray gun yields an electrostatic charge to fuse the powder to the material being coated.
After the powder coating application, the piece goes in a curing oven. There, heat catalyzes the chemical reaction. This leads to a high cross-link density within the coating that’s highly durable. This process is most often used on metal, but it can be used for some non-metallic substances.
Can You Powder Coat Over Powder Coat?
The simple answer is yes. You can powder coat over powder coat. Objects with powder coating are frequently excellent bases for applying another powder coating.
Powder coating over existing powder coating may not always be the best choice. Any imperfections within the existing powder coat might yield more substantial imperfections in a second coat. These imperfections can include bubbling, spots, fish-eyeing, and various other issues with the material.
These imperfections can often be resolved by outgassing, sanding, or buffing: these may be better solutions than applying another powder coat.
Consider Before Applying Another Powder Coat
Before applying a second powder coat on top of the first one, consider your options. There may be a better resolution than applying another powder coat. Consult with professionals like AR Powder Coating to help you determine the best solution.
Applying another powder coat isn’t as simple as spraying on another powder coat and curing it. The original powder coat must be completely stripped from the material first. None of the original powder coating can be present. Stripping off a powder coat is a difficult process that often requires sandblasting and/or chemical stripping agents.
How You Can Powder Coat Over an Existing Powder Coating
Powder coating over powder coating is a bit of a misnomer, since the process requires stripping away all of the previous powder coating first. It’s more like powder-coating the original material all over again.
Once the material is completely stripped and prepped for its new powder coating, there must be no imperfections in the material. Powder coating should always look flawless. Any material concerns must be addressed before adding another powder coat so that you don’t run into the same problems.
Powder Coating Non-Metallic Materials
Powder coating sticks to metal because of the electrical charge. Simply spraying it onto wood, glass, plastic, or other non-conductive materials will cause the powder to slip off.
There are solutions for this. Preheating non-metallic materials allows the powder coat to melt when it comes in contact, so it sticks to the surface. After the material and the powder coat cool down, it’s returned to the curing oven. This can be a tricky method, since the powder coat can become runny and compromise its integrity and durability.
What is Hot-Flocking?
Hot-flocking is another method of powder coating non-metallic materials. Like preheating, the material gets placed in a curing oven until it reaches a temperature of 400 degrees. It is then removed and immediately sprayed with the powder coat. The powder melds instantly and flows properly for an even application.
What About Heat-Sensitive Materials?
For heat-sensitive materials, such as wood or some plastics, UV-curable powder coats require minimal heat for curing. The pieces are coated and enter the curing oven, allowing the coating to melt and flow for several minutes. Then they’re exposed to ultraviolet light for a few seconds for the final curing and hardening of the finish.
Using these advanced methods, materials like wood, plastic, composites, glass, and medium-density fiberboard can be powder coated effectively.
If you’re looking to powder coat a non-metallic material, make sure you’re using experienced professionals that understand the unique process, such as AR Powder Coating. A variety of powder coating techniques are available, and our experts can tailor the process for heat-sensitive materials.
Learn More At AR Powder Coating
Powder coating is best handled by professionals. Considerable equipment and expertise are involved. If you want your powder coating to look flawless, take your project to the professionals.
AR Powder Coating is the Las Vegas area’s premier iron, powder coating, and media blasting company. We have over three decades of experience in the ironworks industry. Trust AR Powder Coating to evaluate your project fairly and give you the best options available. Contact AR Powder Coating for your next powder coating project today.