Painting a car with acrylic paint: technology from A to Z

Acrylic paint remains one of the most popular car paint materials due to its durability, vibrant colors and relative ease of application. However, even with such a “forgiving” material, errors at the preparation stage or the painting itself can lead to defects that will be difficult to eliminate without a complete repainting. This article is not about “general advice”, but about concrete steps, which are divided into stages taking into account the nuances of working with acrylic compositions of different brands - from budget Mobihel to professional Sikkens or PPG.

We will analyze not only the classic “wet on wet” technology, but also alternative methods for local repairs, and also tell you how to avoid typical problems: spotting when drying, shagreens from incorrect spray gun pressure and delaminations due to poor adhesion. We will pay special attention to surface preparation - beginners spend 50% of the time moins than required on this stage, although it determines 90% of the final result.

If this is your first time painting a car, after reading this you will know:

• 🔧 How to choose paint and related materials (primer, solvent, varnish) to suit your budget and working conditions.
• 🧴 Why epoxy primer better acrylic for metal, and when you can do without it.
• 🎨 How to set up a spray gun for acrylic (pressure, nozzle size, paint viscosity) to avoid smudges.
• ⏳ How many layers to apply and how to control the thickness of the coating without an expensive device.

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

Acrylic paints for cars are divided into three main categories, and their choice depends not only on the budget, but also on the painting conditions:

• 💰 Budget (1K): Mobihel, Novol, Body. One-component, do not require a hardener, but are less resistant to UV and chemicals. Suitable for local repairs or temporary painting.
• 🔝 Professional (2K): Sikkens Autowave, PPG Deltacron, Spies Hecker Permahyd. Two-component, with hardener. They give deep color and durability, but require precise mixing proportions.
• 🌈 Special: mother of pearl, chameleons, matte. It is important to consider here that such paints require experience with a gun - they are capricious in terms of application technique.

The key parameter when choosing is viscosity. Acrylic paints are usually applied at a viscosity 18–22 sec (according to DIN 4 viscometer) at temperature 20°C. If the paint is too thick, thin it out special thinner for acrylic (not universal!), if liquid, add a hardener (for 2K systems). Using an unsuitable thinner (for example, 646 for acrylic) will lead to clouding of the varnish and delamination of the coating after 6-12 months.

When purchasing, check:

• 📅 Expiration date: acrylic paints and hardeners “age” even in a closed jar. The optimal age is no older than 12 months.
• 🌡️ Temperature range: some paints (for example, PPG Envirobase) require drying at +23°C and above.
• 🔄 Soil compatibility: if you use epoxy primer, the paint must be compatible with it (check with the manufacturer).

⚠️ Attention: Do not buy acrylic paints “by weight” from dubious sellers. Counterfeits are often diluted with cheap solvents, which leads to uneven polymerization - the coating will be soft and will crack quickly.

2. Preparing the car for painting: steps that should not be skipped

This stage takes up to 70% of the time of the entire process, but it is this stage that ensures that the paint will not peel off after a year. Let's start with degreasing and removing old coatings.

Removing old paint and rust:

• 🛠️ Mechanical method: using a grinder with an attachment P80–P120 for rough cleaning, then P220–P320 for finishing.
• 🧪 Chemical method: use paint remover (for example, Body 700), but only in a well-ventilated area - the vapors are toxic.

Putty and leveling:

• 🟨 For deep dents use fiberglass putty (for example, 3M Bondo), for small ones - finishing polyester.
• 📏 The thickness of the putty layer should not exceed 3–5 mm. Thicker layers crack when dried.
• 🔨 After drying, the putty is sanded P180–P240, then P320–P400 for smoothness.

Priming: This is a required step, even if you are painting using old paint. The primer provides adhesion and protects the metal from corrosion.

• 🛡️ For bare metal: epoxy primer (for example, PPG DP40/DP40LF). Apply a thin layer and dry for 2–4 hours.
• 🟢 For plastic: adhesive primer (for example, Sikkens Autoclear Plus). Without it, the paint on plastic parts will peel off in 3-6 months.
• 🔳 For putty: acrylic primer filler (for example, Novol Protect 340). Apply in 2-3 layers with intermediate drying.

After priming, the surface is sanded P500–P600 (for acrylic paint) or P800 (if varnish will be applied further). Dust after grinding must be removed with anti-silicone. (for example, Prepsol or App Wash&Gloss).

3. Equipment setup: spray gun, compressor, box

Even the most expensive paint will look terrible if applied with the wrong equipment. Let's look at the key parameters:

Spray gun:

• 🔫 Type: Suitable for acrylic HVLP (high transfer, low pressure) or LVLP (low air flow). For example, Satajet 4000 B or Waldom W100.
• 🎯 Nozzle size: Optimal 1.3–1.4 mm for base paint and 1.5–1.7 mm for varnish.
• 💨 Pressure: At the entrance to the pistol - 2.5–3.0 bar, at the outlet (at the nozzle) - 0.7–1.2 bar (depending on the model).

Compressor:

• ⚙️ Productivity: no less 250–300 l/min for a stable air supply.
• 💧 Moisture separator and filters: required! Moisture in the paint will cause craters and bubbles.
• 📉 Pressure: should be stable. Differences more 0.3 bar will spoil the texture of the coating.

Paint booth (or garage):

• 🌡️ Temperature: 20–25°C. At temperatures below 15°C acrylic does not polymerize well.
• 💨 Ventilation: must provide laminar flow (no turbulence), otherwise dust will settle on the fresh paint.
• 🔦 Lighting: no less 1000 lux. Use LED panels with color temperature 5000–6000K for accurate color reproduction.

Parameter	Optimal value for acrylic	Consequences of incorrect settings
Paint viscosity (DIN 4)	18–22 sec	Too liquid - smudges; too thick - shagreen.
Gun outlet pressure	0.7–1.2 bar	Low - poor atomization; high - excessive fog.
Distance from gun to part	15–25 cm	Closer - smudges; Next - dry spray.
Gun speed	30–50 cm/sec	Slow - thick layer; quickly - uneven coverage.

⚠️ Attention: If you are painting in a garage without a spray booth, use dust filters at the air inlet and dehumidifier with silica gel. Even one speck of dust falling on fresh varnish will ruin the whole job.

4. Acrylic paint application technology: step-by-step instructions

Now we move on to the most important stage. Acrylic paint is applied to 2–3 layers with intermediate drying. Let's look at the process in detail:

Paint preparation:

• 🧪 Mix the paint with hardener and thinner in the proportions specified by the manufacturer (usually 2:1:10% for 2K systems).
• 🔄 Mix with a mixer at low speed (300–400 rpm) during 3–5 minutesto avoid air bubbles.
• 🕒 Give the paint a rest 10–15 minutes after mixing - this is called induction period.

Applying the first layer (base):

• 🎨 Set your gun to wide torch (air adjustment to maximum).
• 🖌️ Hold the gun at an angle 90° to the surface, move parallel to the part.
• 🔄 Apply paint overlapping stripes (by 50%) at a uniform speed.

The first layer should be thin and uniform — its task is to ensure adhesion. Dry it 10–15 minutes at 20°C (or according to the instructions for the paint).

Application of the second and third layers:

• 🔍 Before the second layer, check the first for defects: if any omissions or specks of dust, delete them sticky napkin (for example, 3M Tack Cloth).
• 🎨 The second layer is applied more densely, but without smudges. If paint metallic, it is important to maintain the same gun distance to avoid uneven distribution of aluminum flakes.
• ⏳ The third layer (if needed) is applied after the second has dried for 15–20 minutes.

Check the viscosity of the paint with a viscometer|Adjust the pressure on the gun|Make sure there is no dust in the box|Wear a respirator and gloves|Prepare sticky wipes to remove debris-->

Drying:

• ⏳ When 20°C acrylic paint polymerizes 6–8 hours, but full strength is achieved through 24–48 hours.
• 🔥 To speed up drying you can use IR heaters, but the temperature should not exceed 60°C - otherwise the paint will turn yellow.
• 🚫 Do not dry paint in direct sunlight - this leads to uneven polymerization and spots.

5. Applying varnish: final stage

The varnish gives the paint depth and protects it from UV rays and mechanical damage. Used for acrylic paints two-component varnishes (for example, Sikkens Autoclear Plus or PPG Global Refinish).

Varnish preparation:

• 🧪 Mix varnish with hardener in proportion 2:1 (or according to instructions).
• 🔄 Add 5–10% thinner to improve spreadability.
• 🕒 Let the mixture sit 5–10 minutes before application.

Application technique:

• 🎨 Use a nozzle 1.5–1.7 mm and pressure 2.0–2.5 bar at the entrance.
• 🖌️ Apply varnish in 2–3 layers with intermediate drying 5–10 minutes.
• 🔍 The last layer should be the thickest - it determines the final gloss.

Drying the varnish takes 12–24 hours at 20°C. It gains full strength through 7 days, therefore, at this time the car should not be washed or subjected to mechanical stress.

⚠️ Attention: If after drying the varnish there are cloudy spots, this is a sign insufficient polymerization. The reason is too low a temperature or high humidity. The only way to fix it is by polishing or repainting.

6. Polishing and finishing

Even perfectly applied paint requires polishing to remove micro-irregularities and achieve a mirror-like shine. The process consists of several stages:

Wet sanding:

• 📏 Use waterproof sandpaper graininess P1500–P2000.
• 💧 Work with constant moisture - this prevents the varnish from overheating.
• ⚠️ Do not press the paper hard - light pressure is enough.

Polishing:

• 🔴 Start with abrasive paste (for example, 3M Perfect-It 3000) and hard circle (orange).
• 🟢 Then use finishing paste (for example, Menzerna PO106FA) and soft circle (black).
• 🔦 Polish on speed 1200–1500 rpmwithout allowing the surface to overheat.

Protective coating:

• 🛡️Apply ceramic wax (for example, Collinite 845) or nanoceramics (for example, Ceramic Pro) for long-term protection.
• 🌧️ Avoid washing your car during 7 days after polishing.

After polishing, the varnish should acquire depth and “wet” effect. If minor defects remain (for example, holograms from polishing), they can be eliminated by re-processing with a less abrasive paste.

What to do if scratches remain after polishing?

If visible scratches remain after polishing, it means that you either did not sand the surface enough before polishing, or you used a pad that was too soft. Solution:

1. Repeat sanding P2000 on the problem area.

2. Use a more abrasive paste (for example, Menzerna PO85RD 3.0).

3. Reduce the speed of the polisher to 1000 rpm and increase processing time.

7. Common mistakes and how to avoid them

Even professionals sometimes make mistakes, but beginners almost always encounter them. Here are the most common problems and their solutions:

Problem	Reason	How to fix
Paint smudges	Viscosity too low, gun distance too close, movement slow.	Remove stains by sanding P1200, then polish. When re-staining, reduce the amount of thinner.
Shagreen (orange peel)	High pressure, thick paint, incorrect application technique.	Sand it down P1500–P2000 and polish. When repainting, increase the gun distance.
Spotting after drying	Uneven layer thickness, surface contamination, high humidity.	Repaint the part after degreasing it antisilicon.
Peeling paint	Poor adhesion due to insufficient surface preparation or incompatibility of primer and paint.	Strip paint down to metal, repeat priming with correct material.
Cloudy varnish	Insufficient drying, low temperature, improper mixing of components.	Sand the varnish P1200, then apply a new coat with proper drying.

Tips for beginners:

• 🔧 Train on old parts (for example, a hood or door from disassembly) before working on the machine.
• 📹 Film the process - it’s easier to analyze errors in technology.
• 🧴 Don’t skimp on consumables: cheap tape, brushes or degreaser often cause defects.

8. FAQ: Answers to frequently asked questions

Is it possible to apply acrylic paint over old paint without primer?

Technically possible, but only if the paint is old holds up well and has no chips. However, without primer, adhesion will be weak and new paint may peel off after 6-12 months. For reliability, it is better to matte the old paint P500–P600 and apply adhesive primer.

How many layers of acrylic paint should I apply?

Usually enough 2–3 layers:

• 1st layer: thin, for adhesion.
• 2nd layer: main layer, for uniform color.
• 3rd layer (optional): for saturation (especially important for metallics).

The thickness of each layer should be 15–25 µm. Total paint thickness (without varnish) - no more 80–100 µm.

What is the best spray gun for acrylic paint?

For acrylic, guns like HVLP or LVLP with nozzle 1.3–1.4 mm. Popular models:

• Satajet 4000 B — professional choice, high quality spray.
• Waldom W100 - a budget option with good ergonomics.
• DeVilbiss GTI Pro Lite - universal for beginners.

Important: the gun must be clean and adjusted to the correct pressure.

How long after painting can the car be used?

Depends on the type of paint and drying conditions:

• 🚗 In 24 hours: You can drive carefully, but avoid washing and mechanical stress.
• 🛡️ In 7 days: the varnish gains full strength, you can wash the car and apply protective coatings.
• ❄️ in winter: drying slows down, so it’s better to wait 48 hours before the first trip.

Is it possible to paint with acrylic at home (garage, street)?

Technically yes, but with caveats:

• 🏠 Garage: must be clean, with good ventilation and stable temperature (18–25°C). Use dust filters.
• 🌳 street: not recommended due to dust, wind and uncontrolled temperature. If painting outside, choose a calm day and use painting tent.
• ⚠️ Important: Even in a garage without a spray booth, the risk of dust is high - be prepared for additional polishing.