How to properly apply acrylic paint on a car: technology from A to Z

Acrylic paint remains one of the most popular car paint materials due to its durability, fade resistance and relative ease of application. However, even with such a forgiving material, errors in the preparation or painting stage can lead to defects that will be difficult to eliminate without a complete repainting. This article is not about “approximate” application, but about professional approach, which guarantees an even gloss and durability of the coating for years.

We will walk you through the entire process from selection of materials (including primers and solvents) up to final polishing, paying special attention to the nuances that are often silent about in “general” instructions. For example, why at temperatures below +15°C, acrylic paint loses up to 40% of adhesion, even if the manufacturer indicates a range of +10°C. Or how to properly “stretch” layers to avoid the “orange peel” effect without using expensive equipment.

The article will be useful for both beginners and experienced professionals who want to systematize their knowledge. All recommendations are based on standards PPG, Sikkens and Mobihel — leaders in the car enamels market. Let's get started!

1. Choosing acrylic paint: what you need to know before buying

Not all acrylic paint is created equal. Even in the line of one manufacturer there may be compositions with different degrees of gloss, hiding power and drying time. Here are the key parameters to pay attention to:

• 🔹 System type: 1K (one-component, air-dry) or 2K (two-component, requires a hardener). Preferred for bodywork 2K - it is stronger and retains color longer.
• 🔹 Covering power: an indicator of how many layers will be required to completely cover the old color. With high-quality paints (for example, PPG Deltacron) coverage - 90-95% in 2-3 layers.
• 🔹 Interlayer drying time: for acrylic paints usually 5-15 minutes at +20°C. If the garage is colder, the time increases by 1.5-2 times.
• 🔹 Soil compatibility: Not all acrylic paints will work on epoxy or acid primer. Check the manufacturer's recommendations!

A mistake many car owners make is buying paint “by color” without taking into account its purpose. For example, acrylic-urethane compositions (for example, Sikkens Autocryl) are suitable for full painting, and acrylic-melamine (type Mobihel Acryl-Melamin) are best used for local repairs due to their high adhesion to the old coating.

⚠️ Attention: If you are painting with metallic paint (such as "silver" or "graphite"), be sure to buy base and varnish one brand. Different manufacturers use different sizes of aluminum flakes, which will result in an uneven shine.

2. Surface preparation: the key to coating durability

Even the most expensive paint will not save you if the surface is poorly prepared. Preparation takes up to 70% of the time of the entire process, but it is this that determines whether the coating will last for years or will begin to peel off after six months.

Main stages:

1. Cleaning: remove dirt, grease and silicone polishes using degreaser (for example, App W900). No household solvents!
2. Sanding: remove old paint with sandpaper P800-P1200 (for local repairs) or P400-P600 (for complete painting). Bare steel is ground to P180-P240.
3. Priming: apply 2-3 layers epoxy primer (for example, PPG K36) to protect against corrosion, then 1-2 layers acrylic filler (type Sikkens Autocryl Filler) for alignment.

After priming, the surface must be sanded P500-P600 (wet sanding) to remove shagreen and ensure perfect paint adhesion. Skipping this step means getting a coating with micropores in which dirt will accumulate over time.

3. Equipment setup: spray gun and compressor

The correct setting of the equipment determines whether the paint will go on smoothly or will appear in spots. Main parameters:

• 🔧 Spray gun outlet pressure: 1.8-2.2 bar for acrylic paints. Too high pressure will produce “fog”, too low - drips.
• 🔧 Nozzle size: 1.3-1.4 mm for base, 1.4-1.6 mm for varnish. For metallics, it is better to use a 1.3 mm nozzle so that the flakes lie evenly.
• 🔧 Distance to surface: 15-20 cm. Closer - drips, further - dry coating.
• 🔧 Paint viscosity: Checked with a viscometer. For most acrylic paints - 18-22 seconds (DIN 4 at +20°C).

If you don’t have a viscometer, you can check the viscosity “by eye”: the paint should flow from the stick in an even stream, and not drip or “tear”. To dilute, use special solvent for acrylic (for example, PPG DT870), not universal 646 - it can cause cloudiness.

⚠️ Attention: If you are painting in a garage without a hood, use respirator with P3 class filters and an eye mask. Acrylic paint fumes contain isocyanates, which can cause chronic lung diseases if inhaled over long periods of time.

Make sure there is no blockage in the nozzle|Check the hoses for tightness|Adjust the pressure on the pressure gauge|Test the torch on an unnecessary part|Heat the paint to +20°C (if it’s cold in the garage)-->

4. Acrylic paint application technique: step-by-step process

Now we move on to the most important stage. Main rule: It's better to apply 3 thin coats than 1 thick coat. A thick layer not only takes longer to dry, but can also cause drips or “boiling” (microbubbles).

Procedure:

1. First layer (fog): applied from a distance of 20-25 cm with an almost dry spray. The goal is to “spray” the surface for better adhesion.
2. Second layer (main): distance 15-20 cm, movements overlap the previous passage by 50%. Keep the spray gun strictly perpendicular to the surface!
3. Third layer (leveling): applied 5-10 minutes after the second, more slowly and with a slight increase in pressure (up to 2.3 bar).

For metallics, the technique is slightly different: the first layer is applied “wet on wet” (without drying between layers) so that the scales lie evenly. Then - 10 minutes of drying and applying varnish in 2 layers.

Temperature and humidity are critical:

• 🌡️ Optimal temperature: +20°C ± 2°C.
• 💧 Humidity: no higher than 60%. At higher humidity, the paint will “shrink” (dullness appears).

5. Drying and polishing: final touches

Many people think that after applying the last layer the work is finished. In fact, proper drying and polishing determine up to 50% of the final result. Here's what to consider:

• ⏳ Natural drying: at +20°C acrylic paint gains full strength in 7-10 days. After 24 hours it can already be polished, but it is not recommended to wash the car for another 2 weeks.
• 🔥 Forced drying: in a chamber at +60°C the time is reduced to 2-3 hours. Can be used in the garage infrared heaters, but you cannot keep them closer than 1 meter to the surface - the paint may turn yellow.
• 🛠️ Polishing: Start with an abrasive paste (e.g. 3M 05974 with 3000 grit), then move on to a protective one (such as Menzerna PO85RD). For metallics use non-abrasive polishso as not to damage the scales.

A beginner mistake is polishing the paint ahead of time. If you start polishing before it has fully cured (usually 48 hours), you may smear the layer and end up with dull spots. It's easy to check if it's ready: touch the paint with a gloved finger. If a fingerprint remains, wait further.

6. Common mistakes and how to avoid them

Even experienced professionals sometimes make mistakes that spoil the result. Here are the most common:

One of the most insidious mistakes is using expired paint or hardener. Acrylic formulations have a shelf life of 12-24 months in unopened containers. After opening the can, the paint oxidizes and its properties deteriorate. Always check the production date on the label!

One more nuance: if you paint a part partially (for example, a wing), be sure to make a “smooth transition” on old paint. To do this:

1. Apply the first coat to the repair area only.
2. Extend the second layer 10-15 cm beyond the zone.
3. Apply the third layer with feathering (reducing the density of the spray along the edges).

7. Caring for a painted surface: how to extend the life of paint

Even perfectly applied acrylic paint requires proper care to maintain its shine and protection. Here are the basic rules:

• 🚿 Washing: For the first 2 weeks, hand wash only without pressure. Use pH-neutral shampoos (for example, Karcher RM 519).
• 🛡️ Protection: Apply a month after painting ceramic coating or wax (type Collinite 845). This will protect against UV rays and chemicals.
• 🚗 Parking: Avoid prolonged exposure to direct sunlight. If you don't have a garage, use breathable cover.
• 🔧 Repair of chips: even small chips need to be painted over immediately pencil retoucher (for example, Dr. ColorChip) to avoid corrosion.

Do not use for washing household cleaning products (type Fairy) - they destroy the structure of acrylic and leave stains. Also avoid automatic car washes with brushes in the first 3 months - they can leave micro-scratches.

Frequently Asked Questions