Quality body painting is not just a color layer, but a complex multi-stage process that requires strict compliance with technological maps and sterility conditions. Even a minimal deviation from the regulations can lead to defects that will appear after a few months of operation. Professional car-painting It involves not only working with spray gun, but also competent surface preparation, creating ideal conditions for drying and final processing.
Many motorists mistakenly believe that the main thing is to choose the right enamel and diluent. In fact, 80% of success depends on how the metal and putty were prepared. Violation of adhesion or getting moisture under a layer of paint will negate all efforts. In this article, we will take a closer look at each stage so that you understand the physicochemical processes that take place in the chamber.
To start working, you will need not only a tool, but also an understanding of the principles of paintwork (varnishes). Modern two-component systems require precision mixing and control of exposure time. Ignoring these parameters makes it impossible to obtain factory quality coating.
⚠️ Attention: Work with paints and solvents should be carried out exclusively in a well-ventilated room using a high-quality respirator. Solvent vapors are toxic and can cause severe poisoning or loss of consciousness.
Preparation of the workplace and diagnostics of the body
The first step is always a thorough car wash and degreasing the surface. Any contamination, bitumen spots or silicone can cause craters and fish eyes on fresh paint. Use specialized antisilicone And lilac-free wipes for cleaning.
After washing, a defect is carried out. It is necessary to determine the boundaries of damage, identify hidden foci of corrosion and decide on the scope of the intervention. Often it is necessary to dismantle the hinged elements: handles, moldings, headlights and bumpers. This allows you to qualitatively paint the ends and avoid visible transition boundaries.
It is important to ensure cleanliness in the paint area. Dust is the painter's main enemy. The walls and floor of the chamber (or garage) should be moistened to nail the dust, as well as check the ventilation. The air temperature should be stable, usually in the range of 20-22 ° C, which corresponds to the recommendations of most manufacturers of coatings.
Geometry restoration and spatula
If there are dents on the body, they must be removed before any chemical compositions are applied. For this purpose, a slipper or hand tool is used to edit the metal. After aligning the geometry, the surface is cleaned to metal with an abrasive with grain 80-120. This creates the necessary risk for adhesion.
Spattle is performed to eliminate micronervities that cannot be removed mechanically. Polyester putty It is mixed with hardener strictly according to the instructions on the bank. Excess hardener will lead to brittle layer, and the disadvantage is that the material will not dry.
Apply the material must be across the drawings left by the abrasive, squeezing air from the pores. After drying (usually 15-20 minutes at 20°C), a long grinding process begins. First, a rough abrasive P80-P120 is used to form a plane, then P180-P240 to smooth the drawings.
- 🛠️ Always use a developing powder or aerosol to control the plane when grinding - it shows pits and bumps.
- 🌡️ Do not try to accelerate drying of the putty with a hair dryer, this can lead to the formation of bubbles and uneven polymerization.
- 🧤 Use rubber spatulas of different elasticity to work on flat and curvilinear surfaces.
The Secret to the Perfect Putty
Put the putty in thin layers. The thick layer (more than 5 mm) may not dry inside, which will lead to detachment of the paint and swelling after a few months of operation. It is better to apply two thin layers than one thick one.
Surface submersible
The ground is the foundation of your paintwork. It provides anti-corrosion protection and creates a uniform surface for painting. There are two main types of soil: epoxy (for protection of metal) and acrylic (for alignment). In the technology of painting, two-component acrylic soil-filler is most often used.
Before applying the soil, the surface is degreased again. Mixing of components is carried out in a strict proportion specified by the technical sheet (TDS). The finished mixture must be filtered through a funnel with a mesh (usually 150-200 microns) to prevent lumps from entering the spray gun.
The soil is applied in 2-3 layers with an interlayer exposure of 10-15 minutes. It is important not to “flip” the material to avoid leaks. After complete polymerization (usually 12-24 hours or 1 hour at 60°C in the chamber), the soil is polished with an abrasive P400-P500 under enamel or P800-P1000 under a base with a transition.
☑️ Checklist for preparation for priming
Colouring and paint selection
Getting into color is both an art and a science at the same time. Even if you buy paint by body code, the actual color may differ due to the burnout of the old LCP or the features of the plant lot. Therefore, before the main painting is necessarily done. staining Test spray on a metal plate or an unnecessary part.
The coloring process involves adding mixts (pigments) to adjust the hue. You need to evaluate the color in different lighting: in the shade, in the sun and under artificial light. Metals and pearls are particularly sensitive to grain size and viewing angle.
If you work with three-layer coatings (base + mother of pearl + varnish), the technology becomes more complicated. It is necessary to accurately reproduce the number of layers of mother-of-pearl, since the depth and saturation of color depends on this. A single-layer error can give a strong go into a green or purple shade.
| Type of coating | Number of layers of base | Drying time between layers | Features |
|---|---|---|---|
| Acrylic (Solid) | 2-3 layers | 10-15 minutes | It does not require varnish, but less resistant. |
| Metallic (Basecoat) | 2-3 layers | 10-20 minutes | Requires mandatory coating with varnish |
| Mother of pearl (3 layers) | 2 bases + mother of mother of mother-of-pearl | 15-25 minutes | Difficult selection, depth effect |
| Candy (Candy) | 4-6 layers | 30 min | Transparent colored varnish, very difficult to repair |
Technology of application of basic enamel
The application of the base is the most important moment. The Krascopult is held perpendicular to the surface at a distance of 15-20 cm. Movements should be smooth, with the torch overlapping by 50-70%. The first layer is applied thin, "dusty" to create adhesion and avoid dissolution of the soil.
The next layers are applied more saturatedly, but without overflow. The main task is to close the soil and achieve a uniform distribution of metal dust (if it is metallic). Grain orientation directly affects the appearance: if you put the base too wet, the grain will lie chaotic and the color will become darker.
Interlayer exposure is critical. If the next layer is applied too early, the solvent can boil and leave the craters. If you hold it, interlayer adhesion will be broken. The readiness of the layer is checked with a finger in a glove in an inconspicuous place: the finger should stick, but not get dirty.
When painting with metallic last ("control") layer is applied with a drier torch and from a greater distance (25-30 cm). This will help to evenly stack the metal grain and avoid stripes when drying.
⚠️ Warning: Never try to polish a fresh base (metallic) before applying the varnish. This will lead to a violation of the structure of the layer and the appearance of matte spots after varnishing.
Lacquering and finishing
Lacquer protects the base from ultraviolet light, chemistry and mechanical influences. The coloring technology provides for the application of varnish in 2 layers. The first layer is thin, binding. The second - the main, glossy, is applied 15-20 minutes after the first.
When applying the second layer, it is important to create a uniform gloss without a shavern (orange peel). To do this, the torch is opened as much as possible, and the speed of the hand should be constant. Overheating of the surface or too thick a layer of varnish can lead to boiling and clouding.
After polymerization of the varnish (usually 24 hours at room temperature), the surface is ready for polishing. Polishing eliminates fine shaking, dust and gives the coating a mirror shine. Abrasive pastes of varying degrees of grain and polishing circles are used.
- 🌀 For primary polishing, use a hard circle and abrasive paste (Grain 3000-5000).
- ✨ Finish treatment is carried out with a soft circle and an anti-hologram paste to remove micro scratches.
- 🧼 After polishing, be sure to degrease the surface to remove the residues of polish from the pores of the polish.
The quality of the varnish determines the durability of the repair. You can not save on varnish - cheap compositions quickly turn yellow and cloudy under the influence of ultraviolet.
Frequent defects and ways to eliminate them
Even experienced professionals sometimes have problems. Drawings are formed due to too liquid dilution of paint or slow movement of the hand. They are eliminated by grinding after complete drying and repolishing of the site.
Shagrens (orange peel) occurs when the material is too viscous, high pressure or high temperature in the chamber. Light pearls are removed by polishing, strong - sanded and repainted.
Craters ("fish eye") are the result of ingress of silicone or oil. If the defect is deep, the element will have to be repainted completely, since local elimination will not give an ideal result. Prevention - thorough degreasing and cleanliness in the chamber.
Why can the paint peel off in a month?
Most often, the reason lies in poor preparation: insufficiently cleaned metal, the absence of adhesive soil on smooth surfaces (plastic, old coatings) or the ingress of moisture / oil into the compressor pneumonia. It is also possible to violate the proportions of mixing components.
Do I need to remove old varnish before painting?
If the old lacquer does not have chipped metal and does not peel off, it can not be removed completely. It is enough to wrap the surface with abrasive P500-P800 to create adhesion. Complete removal is required only in the presence of serious defects or corrosion under the varnish.
What compressor is needed to paint a car?
For high-quality painting, a compressor with an inlet capacity of at least 350-400 liters per minute (for the head) and a receiver of 50 liters is required. The pressure at the output should be stable, without pulsations, which requires the presence of a moisture separator and reducer.
How much dried car paint?
The drying time depends on the type of material and temperature. Basic enamel dries "on the stick" for 15-30 minutes. The varnish gains primary hardness in 2-4 hours at 20°C. Full polymerization (maximum strength set) takes 7 to 30 days.
Can I paint my car in the winter in an unheated garage?
It's not recommended. At temperatures below 15-18°C, the materials do not polymerize properly, leading to defects. In addition, cold air contains less moisture, but when heated in the garage can fall condensation on the freshly painted surface.