A well-applied coat of auto body paint enhances your vehicle’s appearance and protects it from environmental elements. An experienced auto body shop can ensure high quality and longevity.
There are four basic types of car paints on the market today: acrylic lacquer, acrylic enamel, urethane, and water-based. The latter type is the newest innovation and most popular among customers because it does not contain hazardous solvents, making it more eco-friendly.
The first layer on the vehicle is a primer, which prepares the car’s surface to accept and hold the rest of the paint. The paint won’t adhere without it, and the car will experience problems such as flaking, chipping, and rusting. Primer comes in different colors, and the body shop technician must choose a shade that will match well with the color that the customer wants to be applied on top of it.
After the base coat is applied, a clear coat is added to protect the paint and give it a shiny appearance. Clear coats are made of polyurethane and contain chemicals that help to prevent the car’s paint from fading due to the sun’s UV rays.
Metallic paint is another specialty that has become quite popular recently. That is because it gives the vehicle a sleek, elegant look. It is more expensive than solid paints and can be difficult for the body shop to repair if damaged. Lastly, chameleon paints give the vehicle an illusion of changing colors and sparkling.
The primer layer is the first step in getting a good, quality paint job. It’s essential for ensuring the base coat and clear coat stick to the metal frame. Without it, the paint would sag and flake off quickly.
There are many different types of auto primers, and which one you choose depends on your specific project needs. For instance, some primers are better for quick repair, while others offer extra corrosion protection. They also withstand sanding differently.
Polyester primer, for example, has an excellent “build” – it fills small scratches, dings, and dents much like putty and offers a great bonding surface for the base coat. It also dries very quickly. However, it doesn’t sand as well as epoxy or urethane primer.
Acid etch primers are another fast-drying option. They don’t have the same level of build as polyester primer, but they provide a great bonding surface for the base coat and help prevent rust and corrosion. They’re often used in body shops to speed up repair times. They sand very well but are less durable or chemical-resistant than other primers. Lastly, there are sealers or ‘primer-sealers.’ These are applied over ground and painted vehicles to improve adhesion, provide a uniform color background for the new paint, and act as a solvent barrier to help prevent sand scratch swelling and ‘ show through.’
The base coat is the color that goes on top of the primer layer. It has no strengtheners or hardeners, so it’s just raw paint coated over the primer layer. If left by itself, this will not protect the primer layer or metal frame very well; blemishes can show through the base coat paint and allow moisture to creep in and result in rusting on the surface of the frame.
Because of this, base coats are typically used in conjunction with a clear or urethane base coat to provide better and more effective protection for the paint and the metal frame. The clear or urethane will also give the paint a glossier finish.
Many different base coat paints are available, including acrylic enamel, urethane, and waterborne. These different types offer a variety of benefits, such as durability, resistance to fading, and easy application. Choosing the right base coat paint for your shop will help you achieve a high-quality, professional-looking finish that lasts years.
There are many factors to consider when selecting a base coat, but the most important one is quality. A low-quality base coat will lead to poor adhesion and a less-than-perfect finish. It’s also important to ensure that the base coat is compatible with the primer and clear coat you plan to use. Using incompatible products can cause bonding and drying problems, so double-check before making your selections.
The top coat adds shine and protection to the painted surface. It can also enhance the color and visual appearance of the paint. It can be solid, pearlescent, or metallic. The most common is a clear coat or colored coating over the base.
Acrylic lacquer was the original finish on cars back in the 1920s. While it is still used, especially in older restorations, it does not match the weather and chemicals of modern-day car use. It chips easily and does not provide the UV protection your car needs.
More recent advances in paint technology have brought us non-toxic water-based paints. These are great for the do-it-yourselfer and can be sprayed over any other paint or primer. However, because they do not dry quickly and are very volatile, it is essential to wear the proper safety gear when using these paints (we’ll discuss this more in a future post).
KBS top coat is a one-part formula high solids paint that provides twice the coverage of conventional paints. It is moisture-cured, meaning it dries when humidity is high. That speeds up the curing process and is an important feature in hot climates where humidity can cause paint to dry too slowly. KBS top coat is hard yet flexible for durability and is UV stable. It is often used as a top coat over KBS RustSeal on frames and springs during chassis and restorations.
Lacquers are clear coats that dry through solvent evaporation, leaving a hard protective film. They can be sprayed or brushed on, though most auto paint shops use high-volume, low-pressure (HVLP) spray equipment to get an even coat and avoid drips. Like base and color coatings, lacquers have UV inhibitors to prevent fading from the sun’s rays.
Nitrocellulose lacquers, still used on some classic cars, dries quickly and is fairly inexpensive. It has a slightly amber hue that enhances dark and light woods and can be rubbed to produce a smooth surface that resists stains, scratches, and abrasions. However, it is susceptible to yellowing and requires sanding between each application of new lacquer.
Acrylic lacquers, developed in the 1950s, have a water-white tint and don’t yellow as fast as nitrocellulose products. They contain synthetic acrylic polymers and are more flexible than traditional lacquers. Some acrylic lacquers are post-catalyzed, meaning the catalyst comes separate from the finish and must be mixed in before use.
Urethane, a clear topcoat less expensive than other types of finish and dries quicker than lacquer, has become an auto industry mainstay. It’s also durable and resistant to chemicals and abrasions. Unlike lacquer, urethane doesn’t need to be sanded between each application of clear coat and isn’t as sensitive to moisture. However, it can have a plastic look, and technicians often prefer lacquer for refinishing projects on older vehicles where a “showroom sheen” is important.
From the fire-engine red, glacier white, or plum crazy purple paint job on your vehicle to the metals welded together to create its frame and body, car manufacturing is much more sophisticated than it was in Henry Ford’s day. And though your car is primarily made of strong metals, they still break down over time due to heat, moisture, and harmful chemicals. Paint helps slow the breakdown of those metals and protects the body from damage.
In the past, auto-body paint was a single-component paint that dried at room temperature through solvent evaporation. However, two-component catalyzed paint is now used for mass production and dries in ovens. This type of paint needs a specialized primer to prepare the surface for its application, as without it, the base and clear coats won’t consistently bond with the body.
Urethane paint is a modern option that dries quickly, is more durable than lacquer, and can be buffed to a brilliant shine. However, it’s more toxic than other types of auto paint and needs to be applied in a mask by a trained technician.
Metallic paint, which first appeared on cars in the 1960s, is similar to standard urethane paint but has a small amount of powdered metal added to it that picks up and reflects light differently. Matte finishes also started making their way into factory paint jobs about a decade ago and are typically finished with a clear coat to add shine.