Car body elements – plastics – problems

Sometimes we can see vehicles, where the individual car body elements differ in shade from the others.

Let’s say that it is not a planned effect. The first thought – the colour shade is not properly selected. But not necessarily. In close examination the same differences may be noticed on some brand new cars. What causes those problems?

The plastic lacquered elements, which currently cover large vehicle areas, may be the reason.

The OEM (factory) paint shops are divided in respect of the lacquered substrate. Lacquering of metal elements takes place in another section than plastic elements.

It may cause the colour differences of lacquered elements. The main problem is that there are different lacquering techniques (lacquer layer thickness, substrate colour) for the described elements. Obviously the producers try to eliminate such problems and most cases they are successful. But it sometimes happens, that even using the same lacquering technique for the plastic and metal elements may cause the visible differences in the colours shades.

It gives some valuable information for the lacquering personnel. In order to eliminate the colour differences we try to follow the following principles: Select proper colour shade and perform the test spraying on proper substrate. Control the lacquering parameters: pressure, distance, jet width, number of layers.

Pay attention to the factory “primer” colour.

Use “shading’ technique during lacquering.

Take care also of correct substrate preparation before the lacquering works (I recommend using special antistatic washing agents for degreasing of lacquered plastics). Keep in mind that the main goal of lacquering repair is to obtain the colour consistency of lacquered elements, but in special cases the shade difference may be intentional, e.g. on the bumper, as in OEM lacquering.