What is a paint clouding or cloudiness?
Clouding appears in the form of irregular stripes or spots and in different shades after applying the finish paint. Some areas show lighter and others darker streaks.
Clouding or cloudiness in paint usually occur due to an irregular and random orientation of the aluminium particles on the repaired surface.
The way it is applied by the professional will determine the way these particles are positioned and placed on the part. Metallic particles will reflect light in one direction or another depending on their arrangement, giving rise to possible differences in shades and colour saturations.
As mentioned before, clouding in the repainting process usually occurs with metallic colours, mainly with shades of grey and champagne.
Let us now look at the causes that lead to the appearance of clouding or cloudiness in the paintwork of a car, and their possible solution:
Como hemos comentado anteriormente, las sombras durante el repintado suelen presentarse en colores metalizados, principalmente en colores grises y tonos champagne.
Veámos ahora las causas que provocan la aparición de ráfagas o sombras en la pintura de un coche, y su posible solución:
Causes of the appearance of clouding or cloudiness on car paintwork
The reasons why this defect may appear have to do with several factors:
1. Incorrect position of the application equipment
To prevent the appearance of clouding during the repainting process, the colour must be applied positioning the spray gun totally perpendicular to the surface, so that the spray pattern impacts uniformly on the entire part.
Otherwise, an incorrect position of the gun will cause an uneven distribution of the product in different areas of the surface, favouring the appearance of clouding or cloudiness.
In addition, you must press the trigger right to the end for pigments to be evenly distributed.
2. Inadequate condition and adjustment of the gun
The gun used must be in good condition, with regular maintenance and cleaning, to ensure a correct product flow, free of any dirt.
It is also advisable to check the fan pattern or spray pattern, to ensure a uniform distribution of aluminium particles. To do this, use paper or cardboard to check the size and shape of the spray.
If the pattern is defective, check that the gun nozzle, fluid nozzle and paint nail are in good condition.
Also, as usual, always adjust the spray gun based on the specifications of the product’s technical data sheet .
3. Wrong overlap of layers
An incorrect overlap of layers will cause an irregular distribution of the amount of product applied, which may lead to eventual clouding in the paint.
If you wait too long between layers, alternate stripes with different paint loads will appear, resulting in colour clouding.
4. Absence of effect coat
In metal colours, it is highly recommended to always apply a final effect coat at a slightly greater distance from the part, in order to distribute and direct the metallic particles evenly.
This effect coat is essential in colours with complex colour matching such as certain metallic colours or three-coat colours.
5. Inappropriate paint viscosity
An inappropriate mixture viscosity will hinder the distribution of aluminium particles in the paint coat, causing irregularities in their direction. This is why, once again it is essential to follow the specifications provided in the technical data sheet.
Using slow evaporation thinners will favour the correct distribution and coupling of aluminium particles.
6. Incorrect clear coat application technique
Applying the first clear coat layer with excessive pressure or at too short a distance from the part can cause the aluminium particles to be removed from the surface, which can lead to the appearance of clouding or cloudiness.
Pay special attention to this clear coat and try to apply it uniformly and evenly.
Steps to fix paint clouding or cloudiness
Unlike other painting defects, the appearance of clouding in paint, regardless of their size or extension, will force the painter to repeat the finish process.
1. Surface inspection
Once the clear coat has dried, inspect the extent of the damage caused carefully.
2. Apply the finish paint again
If clouding or cloudiness is observed on the surface, you will have no choice but to apply the finish paint again, this time taking into account all the causes described in the post.