ENGINEERING THE SKIN-DEEP BEAUTY OF THE CHEVROLET CRUZE

By General Motors, Lordstown - Beauty may only be skin deep, but that doesn't mean it's easy to create. Paint engineers spent more than five years developing each of the exterior colors used on the Chevrolet Cruze. To ensure a beautiful, long-lasting finish, engineers have an array of technologies and tests at their disposal, from an advanced primer coating to bird poop.

"Half of the chemistry applied to a car contributes to its color, luster and appearance," said Maureen Midgley, executive director of Global Paint & Polymer Engineering at General Motors, "while the other half contributes to its durability, longevity, and the quietness of the ride. Our goal is to combine those materials to create a flawless finish and consistent color that lasts for the life of the car."

To understand the engineering behind the Cruze exterior appearance, it's best to start at the end of the paint shop at Lordstown Assembly. A $160 million renovation of Lordstown's paint facility was completed in late 2005, making it one of the most-advanced paint facilities in the United States.

The two visual layers of paint include a clearcoat top layer that creates the wet, lustrous shine and mirror finish, and the base coat that provides the color pigment and light-reflecting sparkle. Under the visible surface are a crystalline zinc-based concersion coating, an electrodeposition primer, and a powder-primer coat. The powder prime is electrically charged, which makes it cling to the metal body like a magnet. The powder is then "baked" to create a durable smooth surface for painting. This process is more environmentally friendly than traditional liquid primers because it eliminates the need for liquid solvents, and is up to 95 percent efficient.

Before they reach plants like Lordstown, every color finish is subjected to up to 1,825 days of constant exposure in one of the harshest environments on Earth - South Florida.

The same climate that attracts so many tourists to Florida can be a brutal test of paint chemistries. New paints are left out in the Florida elements for five years, testing their resistance to environmental factors, including sunlight, saltwater, heat and humidity, and even bird droppings. These test panels are inspected annually to assess the clarity of the clearcoat, the consistency of the color pigment, and the strength of the bond to the metal below.

"We have panels nearing 10 years of constant exposure," said Midgley. "It's remarkable to hold a panel with a painted surface that looks like new, after all that time has passed."

In addition, paints are subjected to multiple tests which check their resistance to stone chips. One of the most challenging tests uses a "gravel-o-meter" which fires marble-sized rocks as fast as 35 miles per hour. The gravel-o-meter test is used to assess both the visual appearance of stone chips, as well as the risk of corrosion to exposed metal underneath.

The cumulative effect of these efforts is a beautiful finish that will stand the test of time.

"One of my favorite measures of paint quality is looking at your watch reflected in the paint surface," concluded Midgley. "With Cruze, you will easily be able to tell the time, today and for years to come."