Paint Preparation for Plastic Bumpers

Plastic bumpers on cars dates back to the 1960s when GM introduced the Endura bumper on the 1968 Pontiac GTO, a body colored design that is able to absorb low-speed impacts. Other manufacturers also began exploring alternatives to traditional metal bumpers. Early on they were primarily used as a styling element on sports cars or specialty vehicles. However, their popularity grew as automakers recognized the benefits of plastic bumpers in terms of cost, design flexibility, and durability.

In 1973 new bumper collision requirements made it mandatory for bumpers to withstand 5 mph impacts without significant damage to the cars. This led to numerous design changes that started with bumpers that stuck out way beyond the car’s body. Soon they discovered they could build a strong bumper design then cover it with a plastic covering that molded in seamlessly with the body. By the 1980s, plastic bumpers became mainstream features on many production vehicles. These covers provided both aesthetic appeal and protection to the underlying bumper structure.

Over time, advancements in plastic materials and manufacturing processes improved the performance and appearance of plastic bumpers. Thermoplastic materials like polypropylene became popular due to their impact resistance, recyclability, and ease of molding into complex shapes.

Despite all of these advances in bumper technology, paint preparation remains key to success when refinishing or initially painting these bumper covers. We Join Matt Roehrick of MCA Kustoms in Faribault, MN to give us insights into painting success. When it comes to preparing plastic bumpers for paint, there are several steps he typically takes to complete the process:

Cleaning: The bumper surface must be thoroughly cleaned to remove dirt, grease, wax, and other contaminants. This ensures proper adhesion of the paint.

Sanding: Matt explains, sanding the bumper surface “completely” is key to success, as paint is both a chemical and a mechanical adhesion to the surface and the factory coatings are known to fail if not properly prepared. He also adds, It’s an opportunity to smooth out any imperfections or scratches in the cover.

Priming: Applying a suitable primer specifically designed for plastic surfaces is crucial. The primer promotes adhesion and helps to prevent issues such as peeling or flaking of the paint.

Painting: Once the surface is properly prepared and primed, the bumper can be painted using automotive-grade paint in the desired color. Multiple coats may be applied to achieve the desired finish.

Overall, proper preparation of plastic bumpers before painting is essential to ensure a durable and high-quality finish that will withstand the rigors of driving and last for decades with proper care.