Self-painting of a car door is a complex technological process that requires not only financial investments in materials, but also certain painter skills. Many owners passenger-car decide on this step, wanting to save on the services of specialized service stations or get a guaranteed quality result under personal control. However, it is worth noting that localization It is often more complicated than it seems at first glance and requires strict adherence to technology.
The main difficulty is to choose the color perfectly and prepare the surface properly to avoid transitions and visible boundaries. If you neglect the steps of degreasing or priming, the paint can swell or peel off after a few months of operation. That is why before starting work it is necessary to carefully study the theoretical basis and prepare the room that will meet the requirements of cleanliness and ventilation.
In this article, we will discuss in detail all stages of the process, starting with the dismantling of elements and ending with the finishing polishing. You will learn about the nuances of working with metallic and mother-of-pearlIt is also about what tools are really needed and what can be saved without compromising quality. Readiness for hard work is the key factor in success in this case.
Tools and materials selection required
The success of painting works depends on the quality of surface preparation and materials used by 80%. To begin with, you will need to purchase two-component acrylic soil, base enamel and two-component varnish.
In addition to chemistry, a tool for application is critical. Using a cheap spray sprayer with duzes of inappropriate diameter will lead to shavenni (“orange peel”), which will then be very difficult to get rid of. For most enamels, the best choice will be a spray gun with a duse of 1.3-1.4 mm, while for thick soils and liquid putty, a duse of 1.6-1.8 mm will be required.
- 🛠️ Grinding machines (eccentric and flat-surfaced) for processing large planes and hard-to-reach places.
- 🎨 Krascopult (pulverizer) with adjustable spray torch and spare duses.
- 🧤 Personal protective equipment: respirator with carbon filters, protective suit and gloves.
- 🧴 Degreaser and antisilicone for the final cleaning of the surface before painting.
Special attention should be paid to the air filtration system in the compressor. Moisture and oil trapped in the paint from the receiver will create craters or fisheye on the surface of the door, which cannot be eliminated without a complete repainting of the element. Therefore, the presence of a high-quality moisture separator and regular cleaning of filters is a prerequisite.
Dismantling and primary surface preparation
Quality to paint the door without removing from it handles, moldings and mirrors, is almost impossible. Removal of elements allows you to get close to the hidden edges and avoid sharp color transitions that catch the eye in certain lighting. In addition, it protects adjacent parts from accidental ingestion of paint or varnish.
⚠️ Attention: When removing glasses and mechanisms, be sure to mark all bolts and fasteners so that when assembled, they do not confuse their installation places. A lost bolt of glass mounting can cause it to be distorted and broken.
Primary washing is done using active foam and a soft sponge to remove the underlying dirt, bitumen stains and road chemistry. After drying, the surface must be carefully inspected. If there are deep scratches to metal or corrosion centers on the door, they must be cleaned to pure metal with a grinder or sandpaper.
Transducers are often used to remove rust, but mechanical cleaning remains the most reliable method. After that, the edges of the cleaned area must be dulled (make a smooth transition) so that the putty does not crack during operation. The boundaries of the sweep should be smooth, without sharp steps.
The next step is to apply acid-soil (phosphate) on bare metal. This two-component composition creates a chemical bond with the metal and prevents the re-emergence of corrosion. It should be applied in a thin layer, observing the drying time specified by the manufacturer, usually 15-20 minutes at room temperature.
Body-slipping and grinding
Putty is necessary to align the geometry of the door after removing dents or deep scratches. For the initial layer, it is better to use compositions with aluminum powder or fiberglass, since they have less shrinkage and good adhesion. The finish layer is applied with a soft putty, which is easily grinded and allows you to achieve perfect smoothness.
It is important not to overdo it with the thickness of the layer. A too thick layer of putty can crack or peel off over time, especially on movable body elements such as doors. Each layer must dry for a certain time, and only after complete polymerization can you start grinding.
Technology of "wet" grinding
Grinding putty can be carried out "dry" or "wet". The dry method is preferable, as water can get into the micropores of the material and cause corrosion of the metal under the layer of putty after a while. Use the P80-P120 abrasives for rough shape and the P180-P240 for finishing.
The grinding process requires constant plane control. Use a grinding rod with a developing powder: it will show all the pits and bumps. If the development remains in the depressions, then there you need to add more putty, and if it is completely sanded before the neighboring areas - then there is a bump that needs to be cut.
After aligning the geometry, the surface is grinded with an abrasive P240 and then P320 under the ground. It is important to create an even risk (scratches) that will catch the primer well. The boundaries of the transition from old varnish to putty should be brushed with a P500 abrasive so that they do not step after painting.
Printing and painting preparation
Soil is the link between metal/paint and paint. It fills in the small risks of grinding and creates a uniform surface. For automotive work, acrylic two-component soil is most often used. It must be diluted strictly according to the instructions, adding a hardener and solvent in the right proportions.
Apply the soil in 2-3 layers with interlayer drying (flash-time) for about 10-15 minutes. The first layer is made thin, almost dry, to provide adhesion. Subsequent layers are applied wet to form the necessary thickness and glossy surface. After drying (usually 24 hours or accelerated drying with an IR lamp), the soil is polished.
The final grinding of the soil is carried out with the abrasive P400-P500 under solid (normal colors) and P600-P800 under metallic. Using too large an abrasive can cause the risk to manifest through the paint after drying (shrinkage). For hard-to-reach places and edges, use special sponges or scotch bright.
- 🌡️ Surface temperature It must be at least 15°C and not above 25°C for optimal polymerization.
- 💨 Cover time. between the layers of soil is critical: undried soil can "boil" under the paint.
- 🧼 Degreasing before painting is carried out twice: before the ground and immediately before the application of the base.
☑️ Check before painting the base
Technology of application of basic enamel
The most important point is the application of the basic enamel (color). It is at this stage that coloring and creating a visual effect occur. The paint must be applied in several thin layers (usually 2-3), giving each layer time to evaporate the solvent (10-15 minutes). The first layer is made semi-dry to avoid undercurrents.
Particular attention should be paid to the viscosity of the paint. It is regulated by the addition of a solvent. Too thick paint will lie “stepping”, which will be difficult to remove, and too liquid can give stains or lose cover. For metallic and mother-of-pearl The consistency should be slightly thinner so that the metal particles lay evenly.
⚠️ Attention: When working with three-layer coatings (base + pearl + varnish), it is critically important to observe the same number of spray passes throughout the surface. Otherwise, the shade of the door will differ from the neighboring elements depending on the angle of view.
After applying the last layer of the base, it is necessary to allow it to dry (usually 20-40 minutes) to a state of “mattosti”. The surface should stop shining and sticking. If you start varnishing too early, the solvent from the base can “boil” under the varnish, leaving matte spots or bubbles.
It is important to monitor the direction of the torch spray. Movements should be smooth, parallel to the surface, with overlapping the previous passage by 50%. Sharp movements or stopping the hand at one point is guaranteed to lead to defects in the coating.
Lacquering and finishing
Lacquer gives depth to color, protects the base from ultraviolet light and mechanical influences. For cars, two-component varnishes are used (HS - high dry residue). The lacquer is diluted with a hardener and, if necessary, a diluent (to regulate the spreading depending on the temperature in the chamber).
Lacquer is applied in 2 layers. The first is thin, binding. The second is the main, wet, forming gloss. Between the layers, a pause of 10-15 minutes is maintained. When applying the second layer, it is important not to overdo it so as not to get undertights, especially on vertical surfaces and sharp faces of the door.
After applying the varnish, the car takes time to fully polymerize. Although it will dry after a couple of hours, it will gain full hardness only after 7-14 days (depending on the type of varnish and temperature). During this period, it is better not to wash or expose the car to moisture.
Use a varnish diluent depending on temperature: fast for cold chamber (up to 20°C), standard for medium (20-25°C) and slow for hot (above 25°C). This will prevent boiling or poor spreading.
Pollination and elimination of defects
Even in ideal conditions, a “shagrin” can form on the varnish or dust can get in. These defects are eliminated by abrasive polishing. You can start polishing no earlier than 24 hours after painting, when the polish will gain sufficient hardness. If polished too early, the structure of the varnish can be damaged.
The process begins with wet grinding with abrasive P1500-P2000 to align the shaver. Movements must be careful, without strong pressure, so as not to wipe the varnish to the base. After grinding, the surface becomes matte, and the task of the polisher is to return the gloss to it.
For polishing, pastes of different abrasiveness and polishing circles are used. First, a rough paste is used to remove the drawings from the sandpaper, then a softer one (polishing) to obtain a deep shine. Completes the process of applying protective wax or ceramic coating.
| Work phase | Material/Tool | Drying time (at 20°C) | Key point |
|---|---|---|---|
| Grounding | Acrylic 2K soil | 24 hours (or 1 hour at 60°C) | Uniform coverage without passes |
| Soil grinding | Abrasive P400-P600 | - | Creating even-handed risks |
| Application of the base | Basic enamel | 15-40 minutes before matting | Thin layers, control sprayed |
| Lacquering | Lacquer 2K HS | 24 hours to polish. | Formation of gloss without fouling |
The quality of polishing directly depends on the hardness of the varnish and the correct selection of abrasive. Do not rush to the finish polish until you completely remove the risks from the rough abrasive.
Can I paint the door without getting off the car?
Technically, this is possible, but it is highly discouraged. Without removing the door, it is impossible to paint the ends and internal faces qualitatively, which will lead to visible transitions. In addition, the risk of paint getting on the neighboring elements of the body (wing, roof, rack), which will have to be long and difficult to wash.
How long does the paint dry on the door?
The drying time depends on the temperature and type of materials. The base dries for 20-40 minutes, the varnish is grasped in 2-3 hours, but the full hardness is gaining in 1-2 weeks. You can polish the polish in 24 hours. When using IR drying, the process can be accelerated by 2-3 times.
Why is there a shaking after painting?
Shagrens (orange peel) appears due to improper viscosity of the paint, too long distance of the sprayer from the surface or improper air pressure. Also, the cause may be insufficient temperature in the paint chamber, because of which the paint does not have time to spread.
Do I need to paint the whole door?
To obtain a high-quality, imperceptible result, you need to paint the entire element as a whole, including the ends. Local paint (spotting) requires the highest skill to defuse boundaries and is often noticeable under certain lighting or through polarizing glasses.