The multiple automotive paint defects can occur and can be presented in the different stages of the process. In this piece of writing, I will talk about some of the automotive paint defects that occur in the different painting processes.
Loss of Adhesion
There is a detachment of the automotive paint in the form of scales. It is presented by an inadequate preparation of the substrate i.e. steel, plastic, cataphoresis or galvanized. Lack of preparation and cleaning of the piece to be painted is frequent in painting of plastic parts where they do not take into account the application of adhesion promoters. To correct this defect, there is no other solution than to sand and redo the automotive painting process.
They are blisters or bulges in the automotive paint. They can occur by evaporation of the solvents retained in the paint or particles of water, caused by poor cleaning or when sanding the water without sufficient renewal of the water or dilute the paint in unsuitable solvents. To correct this issue, sand the base of the blister and perform the process again.
Sinking or mapping
Sinking occurs by application of finishing paints on the rigging that does not have a proper drying process, or by improper application such as wet on wet. It also occurs when there is an erroneous combination of paintings; some diluents may produce these defects. In some mild cases with machine polishing, it can be corrected and in a severe case, it will be necessary to sand and perform the process again.
Variations in Tone
They appear as variations in the tone of the finish. It occurs when there are layers of background with a different color and that come to mix with the new color. To correct it, the automotive paint must be sanded and cured with an epoxy rig and repainted.
They are cracks or fissures that are produced by the tension that occurs between the layers of paint and this happens with the behavior of some materials against the heat. It happens when you apply 2k paint to a 1k paint. It also happens when there is an excessive thickness or the evaporation time is not respected when forcing the drying of automotive paint. To resolve this problem, it is sanded to the base again.
They are bulges or folds on the surface of the automotive paint. It happens when there is an application of acrylic paint of two components in bottom of acrylic thermoplastics or synthetic paints. It also happens by an application with excess in the thickness of some surface, or insufficient time of evaporation. The process should be properly sanded and repeated.
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The defects of the automotive painting may be more visible at the end of the process, so it is so important to perform a careful inspection. To be able to make a proper analysis, you must have excellent lighting, which is the daylight or natural light, in the other condition, it is complicated to make the analysis of the hue and possible defects. Let’s see what the common automotive paint defects are so that you can deal with the right on time.
1 – Discoloration
It is when a yellow or reddish spot appears on the surface of the vehicle. They are produced by excessive application of catalyst in the polyester putty and it affects the color pigmentation in the finished paint. To correct this issue, it must be sanded and cured with an epoxy rig and repainted.
2 – Cracks
In this defect in automotive paint, abundant fissures are observed distributed in an extension. It occurs when the preparation of the paint is incorrectly carried out when using products not specified as diluents, hardeners, additives, and also because of incorrect application of the ratio of quantities. As in most defects, the process must be properly sanded and repeated.
3 – Lack of Coverage
It happens when you can see the bottom surface. According to the pigments, it may be that the paint has a good hiding power, for which a greater amount of application is required for the color to cover adequately. The covering power can be checked on a specimen before application to the piece.
4 – Spots
There are formations of spots with the appearance of a cloud on the surface of the automotive paint. It happens by presence of moisture in the paint film or moisture in the air network or the environment. It is always recommended to paint inside the cabin and even more where adverse conditions are present. The best solution is the repainting of the piece.
5 – Shades
They appear in metallic paints. It happens because of the orientation of the metallic pigments, which can be produced by a dry application in the base, and the respective evaporation between layers is also ignored. The best solution is the repainting of the piece.
6 – Orange Skin
This defect is presented as the texture of the orange peel, hence its name, and it is a defect in leveling the automotive paint. It is produced by the following reasons;
- Paint with high viscosity
- Application distance
- Piece to be painted very hot
- Quick thinners
- Excessively thin paint layers
To correct this defect, it may be sufficient to polish the surface by applying a soft sanding with an 1800 or 2000 sandpaper. If this is not possible to correct the problem, sanding and repainting of the part is required.
Any automotive paint defect should be corrected. Some have higher visibility when they are at the top of the car, others that are at the bottom of the doors are made less obvious, so you should consider the magnitude of affectedness. You may click here for more details.