For many car owners, their vehicle’s paint job is one of its most important features. They may spend hours every weekend giving it the care it needs to look showroom-new for as long as possible. Others may only think about their car’s finish when choosing a color at the dealership. But no matter how much thought you put into your car’s exterior, a lot of thinking goes into its finish behind the scenes. That’s because automotive finishes are an essential means of protecting your vehicle from corrosion and other damage. Here are some of the essential facts you should know about the process and why it matters so much.
Why Does Finishing Matter?
Regardless of the level of protection it offers your car, a paint job’s most crucial function is providing a barrier against rust and other hazards. Sealing your chassis and covering the bare metal protects against water, salt and grit that can eat away at it over time. This extends the lifespan of your vehicle. It also makes cleaning the exterior easier because dirt and mud won’t stick to it as easily.
Key Factors That Influence Automotive Finishing Quality
How well an automotive finish performs on the road is determined by more than just type of coating used. There are numerous factors that can affect a finish’s ability to protect components, including:
- Surface Preparation: The longevity of OEM automotive finishing begins with the right pretreatment process. This includes cleaning, degreasing, blasting, and choosing corrosion-resistant primers. Without this, there’s a risk of premature failures such as peeling or rust.
- Material Formulation: Modern automotive coatings can be formulated using a wide range of chemistries, including acrylics, urethanes, polyesters, and more. Each one offers its own unique qualities in terms of hardness, gloss retention, chemical resistance, and UV stability.
- Environmental Conditions: Temperature, humidity, and the presence of airborne contaminants can affect paint adhesion and coating quality control. This is why controlled environments are necessary for painting high-performance vehicles.
- Application Equipment: The advanced spray application systems in use today are engineered to provide consistent atomization, film thickness, and edge coverage. This is especially important for components with complex geometries.
What Are the Different Types of Finishes?
Depending on your preferences and requirements, you may choose from a number of formulations, colors and materials for your car’s paint, including:
- Waterborne vs. solvent-based paint — Traditional paints contain a solvent base such as enamel, urethane or lacquer. However, recent concerns about the volatile organic compounds contained in these and the associated environmental and health impacts have caused many to switch to water-based paints. These contain far fewer solvents and tend to be safer to use.
- Single-stage vs. two-stage — The main difference between these is the application process. Single-stage paint includes clear coat in the formula and goes on complete in one pass. The latter must be applied in two phases, with the clear coat going on after the base coat. A primer is required in both cases.
- Basic vs. metallic vs. pearlescent — These paints differ in their appearance. Basic colors are the most common, but metallic and pearlescent paints offer enhanced effects and shine.
Modern Automotive Finishing Technologies
Technology continues to push forward, and automotive finishes are no different. Some of the most important recent developments in the automotive finishing industry include:
- High-Solids and Low-VOC Systems: With environmental regulations becoming stricter in most parts of the world, eco-friendly coatings have been developed that contribute less pollution but still deliver high standards of appearance and durability.
- Electrostatic Spray Technologies: The electrostatic coating technique offers improved transfer efficiency, improved evenness, and reduced waste, making it the standard automotive finishing technology in modern manufacturing.
- Advanced Resin Systems: The newest resins on the market provide manufacturers with stronger UV resistance, reduced risk of chipping, and improved gloss retention.
- Powder Coatings: Thanks to the durability and environmental advantages it provides, powder coating applications have become the standard for certain automotive components.
What Does the Process Look Like?
Paint processes require a controlled environment for the best results. This is because fluctuations in temperature, humidity and other environmental factors can affect how automotive paint adheres to a surface. Typically, the automotive finishing process begins with the application of a primer followed by paint that usually is sprayed onto the car with the use of sophisticated equipment. Finally, if a coat of clear finish is required, it is applied after the base paint has dried.
Common Challenges in Automotive Finishing (and How to Prevent Them)
Applying automotive finishes is a complex process that requires skill as well as the right equipment. This makes preventing automotive coating defects a full-time job, and manufacturers need to be careful if they want to overcome common obstacles such as:
- Environmental Contaminants: Anything in the air while coatings are applied can end up becoming part of the finish, which leads to inconsistencies and defects like fisheyes or imprints. This is why coating should be performed in a controlled environment with careful handling.
- Improper Film Thickness: Applying too much or too little coating can have disastrous consequences. From running and sagging to reduced paint protection, preventing such issues requires precision application.
- Improper Curing Cycles: If finishes are not cured long enough, it leads to soft finishes and poor chemical resistance. On the other hand, over-curing has a negative impact on the color and gloss of the finish. This is why it’s critical to pay attention to the required curing time for each type of coating.
- Substrate Variability: Different metals require unique primers and curing scheduled tailored for their unique qualities. Whether you’re finishing steel, aluminum, galvanized steel, or another substrate, it’s important to make sure you’re using the right processes and primers.
Automotive Finishing for Corrosion and Impact Protection
The most important role automotive finishes have is protecting components from the outside world. For example, primers, sealers, and powder-based corrosion protection coatings are necessary for protecting vehicles from corrosive threats such as road salt, moisture, and oxygen exposure. With urethane finishes and advanced clear coats, parts are protected against impacts and abrasion caused by debris and sand. Modern finishes also need to be resistant to chemicals including fuel, oils, de-icers, and industrial pollutants. Excessive UV exposure can lead to fading and oxidation, which is why clear coats and UV-resistant formulations are applied.
Why OEMs and Body Shops Choose Professional Automotive Finishing Partners
Working with a professional automotive finishing partner provides OEMs and shops with numerous benefits:
- Consistency at Scale: With automated automotive coating systems and standardized procedures, professional finishers deliver uniform, OEM-grade results across thousands of parts.
- Reduced Rework and Defects: Using professional capabilities minimizes costly rework because humidity, temperature, contamination, and curing are all tightly controlled.
- Specialized Capabilities: Many finishing partners provide powder coating alongside liquid paint solutions as well as hybrid coating systems and specialized primers for different metals.
- Compliance and Safety Standards: Automakers value the fact that these finishing providers meet OEM coating specifications, automotive paint performance testing procedures, and automotive coating durability benchmarks.
What Can Rhinehart Finishing Do For You?
The automotive sector is just one of the many specialty areas in which Rhinehart Finishing excels. Our capabilities include liquid spray-painting as well as military-grade, highly durable powder coating. We do everything necessary to ensure a high-quality finish, from mechanical cleaning and pre-treatment to comprehensive coatings. With our complete services, automotive manufacturers and body shops can count on receiving some of the best paint and coating finishes available anywhere.