Paintwork can, in some cases, become oxidized. Making it turn matte and slightly fade color. If untreated, it can eventually cause the lacquer and/or paintwork to completely fail. It is most common on red cars, but it can happen with every color.
What is oxidation
Oxidation is a chemical reaction in which the oxidation states of atoms are changed. This process is most known as rust. But can happen on every surface. Paintwork, just like any other surface oxidizes to a degree. During claying and polishing, you actually remove the most out layer of oxidized paint, which often restores a lot of gloss on un-detailed cars. Paint can have a clear coat covering the colored coat, in those cases the colored coat is actually matte. The clear coat cures into a glossy and smooth finish. In other cases, the colored coat cures into a glossy and smooth finish, which doesn’t require the use of a clear coat. Paintwork without a clear coat will show oxidation sooner then paintwork with a clear coat. In both cases, the oxidation can be removed to reveal smooth, un-oxidized paintwork.
When does paint oxidize and how does paint fade
The oxidation process is due to several factors, the most contributing ones on earth is oxygen as its an oxidizer in high quantities all around us. The effects of UV radiation lead to the degradation of polymers, pigments and dye. Which cause the fading effect. While the oxidation process causes the smooth surface to loose its structure, changing from glossy to matte, the UV radiation leads to color change, enhancing the faded look of the paintwork even more. It is possible to have a faded color, without the oxidized surface, or to have an oxidized surface without any faded color.
How to correct oxidized and/or faded paint
In many cases the oxidation or UV damage is superficial. Meaning only the most upper layer of paint is affected. Unfortunately, this is not always the case. In more rare cases the clear coat has started to fail, revealing the colored coat underneath. This colored coat is not very thick, and the oxidation can penetrate as deep – or deeper – then the thickness of the colored coat. In these cases the appearance can be improved, but never restored. A respray is needed.
In the case of an oxidized or faded surface, polishing that layer will remove the oxidized/faded layer and will restore the original look.
Claying is essential before polishing, but because the smooth surface has turned into a very uneven matte surface, there can be more contaminants stuck in the surface. Meaning claying will require more effort to remove all the contaminants.
It should be noted that in the case of a failed clear coat, or the absense of a clear coat will cause your polishing pad to turn into the color of the paintwork. Small particles from the paint will get into your pad, turning it to the color of the surface. A red painted surface will color your pads red, a yellow surface will turn them yellow.
Oxidation and colors
Although the faded and/of oxidized look is more common on red cars, it is not the only color that can oxidize. Fading can happen on every color, and is only subject to the type and amount of pigment that has been used. Oxidation can form more rapidly on certain colors, but can eventually happen on every color.
In the past, many manufacturers decided to use uni paint on colored cars. These uni paints don’t require a clear coat. Green, yellow, red, blue and every other color can therefore oxidize.
Clear coats also oxidize, but don’t show it as clearly. When a car hasn’t been detailed for a very long time, the paintwork will gain a lot in gloss after a good clay and polish.
Prevent future oxidation
Preventing oxidation is difficult. Every substance can oxidize, and oxygen is a well known oxidizer. Even substances like glass and plastic trims oxidize. The most common way to hide it is by covering the colored coat with a clear coat. Some manufacturers of car-wrap claim to block UV damage, which only prevents fading. But the area adjacent to the covered panel might not have this wrap protecting it. Eventually leading to one panel with a faded color, and one panel that has been protected against fading.
Oxidation can be slowed down by using certain protective products. But not stopped. Regular maintenance (like a yearly polish) can remove the oxidation before it become clearly visible.
Applying a clear wrap can cause the wrap to oxidize before the paintwork starts to oxidize, but not all wraps offer the same quality of protection.