Car painting metallic with transition effect is an art that requires not only skills, but also an understanding of the physics of light, the properties of paints and varnishes, and the features of surface preparation. This method allows you to achieve a smooth transition of shades, hide body defects and give the car a unique look. However, even experienced painters sometimes encounter problems: uneven pigment distribution, the appearance of “stripes” due to incorrect base application technique or varnish peeling due to improper drying technology.
In this article we will look at the entire process - from the selection of materials to the final polishing - with an emphasis on key nuances, which distinguish professional painting from amateur painting. You'll learn how to avoid common mistakes, which tools are really necessary, and why. metallics from different manufacturers (for example, Mobihel vs Sikkens) behave differently even with the same application technique. And for those who plan to paint for the first time, we have prepared section with answers to frequently asked questions and a checklist of required actions.
1. What is metallic painting during transition and when is it needed?
Technology "painting in transition" (or blending) implies smooth shading of paint at the border of the repair area and the factory coating. This allows you to avoid sharp contours and make the repair invisible. This method is especially relevant for:
- 🔧 Local repairs after an accident (for example, painting a fender or door).
- 🎨 Creation of unique design solutions (gradients, “chameleons”).
- 🔄 Renewal of faded or faded paint on individual body elements.
Metallics require a special approach due to the presence of aluminum or mineral pigmentsthat reflect light at different angles. If applied incorrectly, these pigments can lie unevenly, creating a "spotty" effect. For example, if you paint metallic base too thick, the pigment will settle to the bottom of the spray gun, leaving the first coat dull and the last coat oversaturated.
It is important to understand that transition is possible only on acrylic and metallic paints — for mother-of-pearl or “chameleon” ones, complete painting of the part is required due to the complexity of selecting the shade. Also, the technique is not suitable for single-layer enamels (for example, for some commercial vehicles), where the base layer is also protective.
2. Materials and tools: what you need for a quality result
The choice of materials depends 80% success. Here is the minimum set that you cannot do without:
| Category | Name | Recommended Brands | Notes |
|---|---|---|---|
| Paint | Metallic base | Mobihel, Sikkens, PPG | Select by manufacturer code, not by visual coincidence! |
| Varnish | Two-component acrylic varnish | Spies Hecker, Lesonal | For metallics, use varnishes with a high solids (from 50%). |
| Solvent | For base and varnish | Body 730 (slow), Body 740 (medium) | The rate of evaporation depends on the temperature in the box. |
| Tools | HVLP spray gun | SATAjet 5000, Iwata W-400 | Inlet pressure: 2.0–2.5 bar, nozzle size: 1.3–1.4 mm. |
Please note spray gun nozzle size: for a metallic base, 1.3–1.4 mm is optimal, and for varnish – 1.4–1.6 mm. If you use a larger nozzle, the metallic pigment will be sprayed unevenly, and too small a nozzle will lead to excess pressure and “dry” spray.
Before buying paint, check its expiration date! Expired metallics often lose their pigment, resulting in a faded transition.
Also prepare:
- 🧴 Anti-silicone and degreaser (3M 08984 or analogues).
- 🧽 Abrasive materials: sandpaper
P800–P1200for grinding andP2000–P2500for polishing. - 🎨 Transparent varnish for the finishing layer (preferably with a UV filter).
- 🔥 Infrared drying or heat gun (to speed up polymerization).
3. Surface preparation: grinding and degreasing
This is the most labor-intensive and responsible stage. Even perfectly applied paint will not save the situation if the surface is poorly prepared. Start with:
- Cleaning details from old paint, rust and dirt. Use a sander with an attachment
P80for rough processing andP180–P240for alignment. - Putties (if necessary). Only suitable for metallics fine-grained putty (for example, 3M Gold), which after drying is sanded to a perfectly smooth surface.
- Degreasing. Use a two-step treatment: first with anti-silicone, then with an alcohol-based degreaser.
Washing the part with car shampoo|Removing rust and old paint|Putty (if there are dents)|Sanding with sandpaper P800–P1200|Degreasing with anti-silicone|Checking for the absence of dust-->
Critical don’t skip the matting stage. Before applying the metallic base, the surface should be matte - this will ensure better adhesion. Use gray scotch-brite or sandpaper P1000–P1200 underwater. After matting, degrease the part again and wipe with a sticky cloth to remove micro-particles of dust.
What happens if you don’t degrease the surface?
A non-degreased surface leads to the formation of craters in the varnish, paint peeling and uneven shine. This is especially critical for metallics, where the pigment can “collect” into microdefects, creating spots.
4. Technique for applying a metallic base: the secrets of a uniform transition
This is where the fun begins—and the hardest part. Key Point: metallic base is applied to 2–3 thin layers with intermediate drying for 5–10 minutes. The first layer should be translucent (“foggy”), and subsequent layers should be more saturated.
To create a transition:
- Apply base to repair area with reserve
10–15 cmoutside the zone. - Spray the second coat with reduced pressure (1.8–2.0 bar) and increased distance to the part (
25–30 cm). - Apply the third layer only to the transition zone, blending the paint horizontal movements with a smooth decrease in pressure on the spray gun trigger.
Never apply a metallic base "wet on wet" - this will lead to uneven distribution of pigment and stains.
The temperature in the spray booth should be 20–23°C. At a lower temperature, metallic will go on “dry”, and at a high temperature it may leak. Also avoid drafts: even a slight breeze can blow pigment off the paint stream, creating streaks.
⚠️ Attention: If you are painting a vertical surface (such as a door), start spraying from the bottom up. This will prevent paint from running off and causing smudges.
5. Applying varnish: how to avoid clouding and shagreen
Varnish is not only protection, but also a “lens” that enhances the metallic effect. It is applied to 2–3 layers with intermediate drying 10–15 minutes. The first layer should be thin (“fixing”), and the second should be the main one. A third coat (optional) is applied for additional depth of gloss.
Important details:
- 🔍 Use varnish hardener in the proportion specified by the manufacturer (usually
2:1or4:1). - 🌡️ The temperature of the varnish and the part should be the same (optimally
20–22°C). - 🌀 Spray varnish cross movements (first horizontally, then vertically).
After applying the varnish, let the part sit 20–30 minutes at room temperature, then transfer to dryer. Complete polymerization takes 24–48 hours, but you can polish it through 12–18 hours (when using infrared drying - after 6–8 hours).
⚠️ Attention: If the varnish is applied too thickly, microbubbles (“boiling”) may form during drying. In this case, sanding and re-varnishing will be required.
6. Polishing and finishing
Even perfectly applied varnish requires polishing. Start with wet sanding P2000–P2500 under water to remove shagreen and minor defects. Then use:
- Abrasive paste (for example, 3M 09374) to remove micro-scratches.
- Polishing paste (for example, Menzerna PO85RD) to restore gloss.
- Protective wax or ceramic (for example, Collinite 845 or Ceramic Pro).
Polish with a soft wheel at high speed 1200–1500 rpm. Movements should be smooth, without pressure. After polishing, rinse the part with water and apply a protective coating.
To check the quality of polishing, use a bright light at an angle of 45°. All defects (scratches, holograms) will be clearly visible.
7. Common mistakes and how to avoid them
Even professionals sometimes make mistakes. Here are the most common:
| Error | Reason | How to fix |
|---|---|---|
| Metallic stains | Uneven pigment distribution | Repaint with proper base application technique |
| Cloudiness of varnish | High humidity or pollution | Sand and apply a new coat of varnish |
| Visible transition boundary | Too harsh blending | Expand the transition zone and repeat painting |
| Varnish stains | Too thick layer or low temperature | Remove stains by sanding and revarnish |
Most often problems arise due to improper preparation of the spray gun or non-compliance with temperature conditions. For example, if the air pressure is too high, the paint will spray dry and the metallic pigment will settle unevenly. Check the pressure gauge settings before each painting!
FAQ: Answers to frequently asked questions
Is it possible to paint metallic without varnish?
No, the metallic base has no protective properties and will quickly fade under the influence of UV rays. Varnish is a must!
How many coats of base are needed for dense coverage?
Usually 2-3 layers are enough. The first layer should be translucent, and subsequent layers should be more saturated. The main thing is not to overdo it, otherwise the pigment will “drown” in the base.
How to choose a metallic color if there is no paint code?
Use a spectrophotometer (eg X-Rite MA98) or contact a specialized store where they will make a computer selection. Visual selection of metallics almost always gives inaccurate results.
How long after painting can I wash my car?
Minimum in 2 weeks — the varnish completely polymerizes only after 14–30 days. Until then, avoid car washes and aggressive detergents.
Is it possible to paint metallic in a garage without a spray booth?
Technically yes, but the risk of defects (dust, debris, uneven drying) is extremely high. If painting in a garage, use dust shields and ensure good ventilation.