During the repainting process, different problems and defects may arise in the paint finish that force the workshop professional to repeat the process from the beginning, with the consequent loss of time and material.
One of the most common defects in car repainting is the appearance of the so-called orange peel effect.
What is the orange peel effect in paint?
The name orange peel is given by the resemblance of the final paint finish to an orange peel. This problem is caused by the lack of stretching or levelling of the paint, resulting in a deformed surface and in an increased thickness of the final coat.
Causes of orange peel appearance in car paint
The reasons why this defect may appear have to do with several factors:
1. Incorrect adjustment of the application equipment.
Correctly regulate the application equipment in pressure, product flow and fan pattern based on the specifications in the technical sheet, in order to obtain a regular and even spray. Too low an application pressure will cause a deficient spraying of product.
2. High application viscosity
Another cause may be an excessive viscosity of the mixture, which will also imply a high application viscosity.
To solve this, you can lower the viscosity by slightly increasing the dilution of the mixture.
3. Failure to adjust the catalyst and solvent to ambient temperature
Always comply with the drying time of the base coats specified in the technical data sheets of each product.
5. Excessive product load
Excessive product load per coat and too much distance between the spray gun and the workpiece will result in a less even coating, favouring the orange peel effect.
6. Incorrect preparation of the base coats
Proper preparation and sanding of base coats, always in compliance with the drying times for each process, will help you to obtain a uniform surface that is optimised for repainting.
Steps to solve the orange peel effect in paint
If the orange peel defect is only present on the surface of the part, you should proceed as follows:
- Sanding of the surface with P1500
First sand the defective area with an emery paper P1500, the area having been previously limited with masking tape, in order not to invade undamaged bordering areas.
- Surface refinement with P3000 sandpaper
Then use a P3000 grit to refine the surface and remove possible sanding marks.
- Cleaning and degreasing of the surface
Once the surface has been sanded, clean the dust generated with a degreaser and a microfibre cloth.
- Polishing and shining
Subsequently, apply a quick cut polish with the polishing machine, ensuring homogeneous pressure and movement. Finally, clean the area with a cleaning cloth to assess the result obtained.
On the other hand, if the orange peel defect is still present in the finish paint if it is excessively thick, polishing will not suffice. You will need to prepare the surface to perform the painting process from scratch:
- First, sand the surface with an abrasive (emery) paper according to the defect to be repaired. Use a degreaser to remove any dust residues generated.
- Then, apply the priming coat, and sand.
- Finally, apply the finishing coat, following the above recommendations at all times to prevent the appearance of this defect.