Color is one of the first things that draw attention when looking at a car. Automotive painting has evolved from an art form into a precise science, especially with metallic or pearlescent finishes, which require exceptional accuracy.
Every automotive painter knows that even a minor flaw in surface preparation can result in visible color mismatches or blending lines, compromising the entire finish. Modern paints are applied in ultra-thin layers and demand exceptional precision in both preparation and color matching. With today’s sonic coating technologies, where base coats can be as thin as 1-2 microns, there is virtually no room for error.
The importance of surface preparation – a key factor for metallic and pearlescent colors
The thickness of automotive paint coatings has been continually decreasing, and consequently, the thickness of the base color layer is also thinner. For instance, after five years of intense research, Lexus developed sonic painting technology in 2012, where the base coat thickness for Sonic Titanium and Sonic Silver was just 12 microns. This was made possible by using sound waves. Thanks to this technique, aluminum particles were more closely packed and arranged more uniformly.
Over the years, technology evolved, and the base coat thickness was reduced to no more than 4 microns. Today, the paint layer is reduced to an unprecedented thickness of just 1 to 2 microns. A prime example of this is the Sonic Cooper color from Lexus’s palette.
Currently, automotive painters must constantly adapt to innovations from car manufacturers. If the surface preparation is irregular or features deep scratches due to poor-quality abrasives, the metallic flakes will not align properly, which will result in visible defects in the repair. If the surface is too smooth, adhesion problems may arise in the next stages of the repair process. This makes the process of sanding the surface an exacting task that requires careful balancing.
Blending paint requires:
- Fine, uniform sanding marks.
- No sanding through the clear coat in the shaded area.
- Perfect, invisible transitions between the old and new layers.
Consequences of improper surface preparation
Sanding automotive paint surfaces must be precisely balanced – the surface should have a uniform scratch pattern that ensures both optimal alignment of the metallic flakes and proper adhesion for subsequent layers. Failing to do so can lead to visible defects:
- Too aggressive sanding marks – the metallic pigments break on microfractures of the surface, resulting in blotches, streaks, and uneven coloring.
- Too smooth of a surface – adhesion issues, which can lead to peeling or delamination over time.
- Lack of uniformity – an uneven substrate causes irregular light reflection, which is especially noticeable in metallic and pearlescent shades.
Tomasz Handerek, Sales & Technical Manager, Mirka Poland says:
“Surface preparation is the key to success; it is the most important process in the end. As automotive coating technologies become more precise, it is essential that every step, from sanding to the application of primers and paints, is executed with the highest level of precision. Mirka Iridium™ Soft not only ensures an exceptional finish but also enhances efficiency and minimizes the risk of errors. This tool meets the exacting standards of professionals and plays a key role in achieving the highest quality results”.
What is the Mirka Iridium™ Soft foam abrasive pad?
The wide range of grit sizes offered by the product allows for perfectly prepared surfaces during most stages of the automotive painting process. Mirka Iridium™ Soft is available in grits ideal for the final stages, from priming to the last sanding before blending, as well as for the blending process itself.
What sets it apart from the competition?
- Versatility: efficient dry sanding in eight grits, from 400 to 2000, for a broad range of applications.
- Flexible foam backing: the soft foam backing adapts easily to contours and curves, ensuring smooth and even sanding.
- Anti-clogging: the Mirka Multifit hole configuration prevents clogging, ensuring a cleaner workspace.
- Long lifespan: precision coating and specialized abrasive grains optimize performance, guaranteeing durability on demanding surfaces.
- Comfort: ease of use translates into greater work comfort, reducing user fatigue during both manual and machine sanding.
- Smooth surface preparation: the fine scratch pattern ensures a uniform surface for the next stage, such as priming, painting, or polishing. It prevents visible scratches after finishing the surface.
- 2-in-1 product: suitable for both manual and machine sanding, it provides delicate and controlled sanding, preventing damage to the coating.
Are you applying pearlescent white or graphite paint? Silver with blending on large, flat elements? These are processes where every detail counts – from the scratch structure to the degree of edge smoothing. According to Mirka, this new flexible foam abrasive demonstrates superiority in such applications.
In today’s world, where information is abundant and opinions are everywhere, first-hand experience remains the most reliable measure of a product’s true value. That’s why Mirka offers a complimentary trial directly in your workshop. Simply request a free demonstration to evaluate its performance in your own working environment.
➡ Click here to order a free demonstration of the new Mirka Iridium Soft flexible sanding pad
➡ Learn more about Iridium Soft abrasive material
