Posted 23 Mar 2022

The most common paint defects in a body shop

Painting mistakes are everyone’s nightmare in a body shop. No matter how careful you are and how much experience you have, problems such as cracking, orange peel, dripping, peeling or poor coverage are always around the corner. The causes of these coating defects can be many and often add up to one another. The good news is that nothing is irreparable and, with some good advice and the right technology, you can even minimize the imperfections.

1. Cracking

Also called wrinkling, this defect consists of a series of more or less obvious cracks in the paint layer(s). The result is just like that of cracked skin.

Essentially, the cause is the different tension between the layers, which can be caused by an incorrect choice of hardeners and/or thinners, excessive use of hardeners, incorrect mixture ratio, extreme paint thickness, or rigidity of the surface product compared to the underlying layer.

In addition to the correct choice of products, such errors can be avoided also by taking into consideration the regulation of the spray booth - mainly temperature and humidity - and the right application times and quantities of the products. 

2. Orange Peel Effect

This common paint defect is easy to recognize: the surface presents small, relatively deep holes, like the skin of an orange. 

Orange peel is typically the result of improper painting technique and is caused by the incorrect choice of hardener, the quick evaporation of thinner or human errors in the painting process (incorrect spraying distance, insufficient pressure that causes poor atomization, wrong temperature of the product or poorly sized nozzle).

3. Dripping

Another common coating defect is dripping, which appears like paint thickening forming undulations similar to sea waves on one or more points of the bodywork. Causes may involve the painter, the products, or environmental parameters.

The painter may create drips due to different thicknesses on the surface. Incorrect distance from the metal surface and non-symmetrical movements are other possible errors. 

In case of widespread dripping defects, the quality of the thinner must be taken into consideration. If the thinner is always the same, there may be a problem with the concentration. 

4. Peeling

Like the cosmetic treatment of exfoliation, peeling is a phenomenon whereby layers of paint peel away from the one underneath. Usually, the main cause is incorrect surface preparation, particularly with regard to sanding or degreasing. However, the choice of products, hardeners, or thinners that are not suitable for the substrate can also cause the paint to peel off the bodywork. In some cases, a too-wet or too-dry paint application can also cause this long-term coating defect.

5. Poor Coverage 

The defect of poor coverage is found when, although the thickness applied is sufficient, the paint does not mask the color of the base or the substrate, leaving evident stains. This coating defect should not be confused with opacity, but the reasons may be the same.

The incorrect choice of hardeners and thinners, the wrong temperature of the paint or the substrate, and working with a wrong-sized nozzle can be among the causes.

Thanks to EPS (Easy Paint System) 2.0, you can reduce the incidence of all these defects in the bodywork coating processes. EPS 2.0 is the application software to aid painting developed in collaboration with manufacturers. By answering simple questions about materials and products, the system suggests the most efficient process in real time, independently setting the right times and temperatures.