Over the past several years, a very obvious trend has arisen in which bumpers (and other plastic parts such as door handles and mirror heads) show a very visible "off color" match when compared to the main body. These off colors are apparent from the point of manufacture, and deemed acceptable, even to the point of a customer purchasing the vehicle. It is our job as technicians, it seems, to make the colors even BETTER than what was acceptable upon manufacture, or point of sale. Not always an easy task.
In order to have satisfied customers, all parties involved (vehicle owner, shop manager, paint staff) need to understand why we see mismatches on plastic parts. Both when brand new, as well as after body shop repairs.
Mismatches on "New" Cars
Most commonly, the mismatches we see on brand new vehicles is a result of outsourcing. Although a car may be assembled in one facility, it does not necessarily mean that the "bolt on" parts come from the same plant as the main body. One facility may be using a different paint manufacturer, different equipment, or operating in a climate that is substantially different than the other plant. In todayâ€™s colors, these differences can easily account perceived color match issues.
The actual color or "pigment" may not be the root cause of the color issue either. Believe it or not, variations in clear coats can cause the same issue. This not only speaks to the clarity of a clear coat product, but also to the film thickness, and texture (orange peel) of the coating.
Sometimes even the best of color matches will create a perceived mismatch. As cars become sleeker and complex in design, panels are lining up at odd angles to each other. Our eyes are now looking at two facets of a color at the very same time (one face on, one at the flip), and the difference is apparent. **Note: General Motors have actually issued a Service Bulletin (ID2346049) regarding this phenomenon on the 2010 Camaro door to quarter panel. **
Mismatches In The Paint Shop
In the Paint Shop, the car is painted all at the same time, in the same facility, same gun, same air pressure, same color mixture, same temperature, same EVERYTHING, yet we will STILL see a color mismatch on our bumpers. It is the ultimate in frustration, but there are reasons for this phenomenon as well.
Plastic bumpers will hold a static charge when compared to sheet metal, and will accept pigments and metallics differently. The metallics will orient themselves differently than on the sheet metal.
Another factor is the temperature of the substrates in question. Plastic and metal will accept and retain heat at different rates. If the metal is hotter than the bumper, the color will look darker (and vice versa).
Finally, there is a factor that can be corrected, and that is to mount the bumper in a position that is similar to how it sits on the car. Meaning, donâ€™t lay bumpers "flat" on a stand, spray "with the grain" of the bumper. There are many effective and affordable bumper stands on the market that make it easy to spray a bumper in an "upright" position. Further to that, it is physically less demanding on the Technician who is spraying the bumper.
Proving Your Point To A Customer
With virtually no confrontation, a customer can easily see the color match issues on todayâ€™s cars by perusing a Dealership lot, or even a mall parking lot.
Most customers will see with ease that these color issues are everywhere, and they likely purchased their vehicle with color mismatches, but never noticed it until being properly and politely informed.
That being said, before a Shop takes on a job, it is pertinent to do a thorough "walk around", and point out and existing color issues to the customer PRIOR to starting repairs!