How to properly apply a clearcoat?

Clear coat: surface preparation.

The final appearance of our car is largely determined by the clear coat. The properties and application method of the paint are of considerable importance here. Current regulations require the use of products with a low content of Volatile Organic Compounds. These are paints created using the latest technologies. Before we focus on the painting process itself, there are a few important things to note. The surface on which we apply the clear car paint must be properly prepared. The undercoat of conventional or water-based base paint is applied according to the instructions in the technical data sheets. After the specified time for the solvents to evaporate, the clear coat can be applied. The area to be coated must be free of dust and dirt.

In this description, I will use CP 2014 UHS (successor to CP 2009 UHS) clear coat by PROFIX. When preparing the UHS paint mixture, use the recommended hardener. No thinner is needed for this paint. Using the manufacturer's recommended hardener will protect against the paint defect of spray mist settling.

When should automotive clear coat be applied?

In order to achieve a satisfactory end result and to make the car body look like new after polishing, it is important not only to properly prepare the surface for the clear coat. We should start preparing the surface for the planned renovation much earlier, even before applying the base coat. Depending on the desired result, it can be applied to an acrylic or epoxy primer or an old top coat. Before applying the primer, however, it is essential to matt the surface by sanding it with the appropriate grade of sandpaper.

The only exception to this is when a fresh primer is applied and a wet base coat is applied on top. In this case, we do not wait for the primer to dry and apply another coat directly onto the wet surface.

How long should I wait before applying the base coat and the subsequent coats of clear coat?

The rules regarding the time intervals between the application of subsequent car care products may not be entirely clear. Different sources publish different information on this topic, and we also have a choice of whether we want to apply the layers wet on wet, dry or semi-wet. It is best to follow the manufacturer's advice, which can be found in the technical data sheets of specific products. This applies to both polishing time and the application of individual coatings.

When is polishing clear coat not very effective?

Regardless of which car chemical we use, we have to take into account the time needed for the solvent to evaporate from the base. It can vary not only due to the choice of different products, but also due to weather conditions. So if you have any doubts as to whether the solvent has evaporated, it is better to wait a few minutes longer than to allow it to remain under the layer of clear coat. If this happens, polishing the clear coat and other cosmetic treatments will not help. Unfortunately, the top coat will not adhere well, and the visual effect may not be satisfactory.

Application of clear coat.

The question often arises as to how many layers of clear coat does a car need? The application of UHS clear coat should not cause any problems. First, apply a half coat, and then, after a short evaporation time, apply a full coat. The optimal nozzle size for the spray gun used is 1.3-1.5 mm.

When painting, remember the distance at which you hold the spray gun from the surface to be painted, which is usually 15-25 cm (see diagram). It is also important to hold the spray gun perpendicular to the surface to be painted, as this affects the durability of the paint (impact strength and adhesion) and the more efficient use of the material. The advantage of UHS paint is the short application time. This means there is less dirt on the surface. Compared to MS paints, the dry coating is also thicker. This is achieved by a higher content of solid particles in the paint.

It is best to paint in a spray booth and start drying after applying the paint for 30 minutes at 60°C.

It is also possible to use IR radiators for drying. Drying times and distances from the surface are determined according to the manufacturer's instructions.

 

 

 

 

 

 

 

 

After the drying process is complete and the surface has cooled down, the polishing of the clear coat can be carried out.

The final result of all the work is a clear coat with high depth and scratch resistance. The clear coat layer allows us to emphasize and bring out the color of the base coat.

How many layers of automotive clear coat should be applied?

Each manufacturer specifies the recommended number of clear coats. However, these are usually minimum values, so it is okay to apply more coats before polishing. It is important not to apply too thick coats at once, as they will take too long to dry.