Orange peel is the term for the unevenness of a layer of paint on top of a surface. When you look closely, the surface resembles the skin of an orange. Many detailers consider orange peel unwanted, ugly and a fault of the painter. Orange peel can be found in the clear coat and also in the colored layer of paint.
Where does orange peel come from
When painting a surface, the painter is spraying a specialized, colored liquid on a surface. This surface has a certain attraction, and the liquid had a certain surface tension. These aren’t exactly the same in every spot. Which causes the liquid to form a very slightly uneven layer on top of the surface. There can be a micron difference in thickness in one spot, and in different spot. The difference in thickness is very noticeable from very close. But when viewed from a distance you can notice how the reflection isn’t as sharp as it could be.
What is orange peel
Orange peel is considered by many as an imperfection, even though it is very difficult to prevent.
Orange peel is an effect that forms when painting a surface. Many blame the painter himself, but most of the automotive industry uses robots to paint cars, and they also show orange peel. There are several theories to prevent it. But in the end it is almost impossible to prevent it 100%. The cause is a mixture of natural liquid behavior, attraction and repelling effect between a liquid and a solid, and the drying of liquid with a certain thickness (viscosity).
How to correct orange peel
Although there are techniques to prevent a large amount of orange peel, it is almost impossible to prevent it for 100%. A perfectly flat and smooth surface is very difficult to achieve without correction after drying. The most common approach is to correct the dried layer of paint. Seeing as polishing itself has little effect, most detailers might look at wetsanding to get the desired result. There are also certain polishing pads that have a similar effect.
You can correct the orange peel on the colored layer of paint only if you polish it after spraying and before applying the clear coat. Although some might suggest that orange peel is only found in the clear coat, it is also present in the colored coat. You just don’t see it very good. Show cars sometimes get a full respray with which the detailer polishes the colored coat before applying the clear coat. The clear coat then gets polished as well for an ultimate gloss effect.
Orange peel in the clear coat is easier te correct, because a car is generally delivered to the customer with clear coat already on it, and a second hand car also already has the clear coat (unless it is a uni coat of paint, which is just one colored layer). The clear coat can then be wetsanded or polished with orange peel removal discs. This process is not for the beginners, and can be risky. The pads are easier to work with then wetsanding, but do need care and attention to be done properly.