The decision to update the body color or eliminate local defects of paint coating (LCP) often leads the motorist to the idea of independent work. This is an ambitious task that requires not only desire but also a deep understanding of the physical and chemical processes involved in enamel application. Quality colouring This is 80% surface preparation and only 20% of the process of spraying the material. Errors in the initial stages can negate all further efforts, turning the glossy side into a matte spot with defects.
Before purchasing expensive materials, you need to soberly assess your capabilities and the availability of a suitable room. The garage should not just be dry, but sealed, dusted and equipped with powerful ventilation. In this article, we will analyze the full cycle of work: from dismantling elements to polishing fresh coating, paying special attention to the nuances that beginners often miss.
It is important to understand that base-enamel and varnish They require different conditions of application and drying. Ignoring temperature regimes or interlayer exposure time will lead to the appearance of shaking, leaks or turbidity of the varnish. We will look at how to avoid these problems and get a result close to the factory.
Organization of workspace and choice of materials
The first step is to prepare the room. Dust is the painter's main enemy. Even a microscopic villi, caught on fresh varnish, will spoil the appearance and require time-consuming grinding. The ideal option is a professional paint camera, but in the garage conditions it is necessary to create an improvised box. To do this, the walls and floor are thoroughly washed, and then moistened with water to nail the settled dust. The ceiling is often hung with a plastic film, which is removed immediately before the start of work.
Particular attention should be paid to lighting. Linear LED lamps with cold white light will allow you to see the smallest irregularities and shades of color. The yellow light of incandescent lamps distorts perception, which can lead to uneven spraying or color transition. The temperature in the room should be stable, in the range from +18 to +22 ° C, since cold air slows the evaporation of the solvent, causing stains, and too hot - provokes rapid drying (boiling) of the paint.
Use tack cloths before each coat of paint. They effectively remove static dust that is not visible to the eye, but will appear on the varnish.
The choice of materials directly affects the durability of the coating. For independent work, water-based materials or classic two-component systems (2K) are best suited. The latter require an exact dosage of the hardener. Polyurethane lacquers They provide high hardness and gloss, but they need to be worked quickly because of the short life cycle of the mixture.
Dismantling, washing and degreasing of the body
Quality bodywork It is impossible without a thorough washing. Use of household chemicals is not recommended, as it can leave a greasy film. It is better to use specialized car shampoos that remove bitumen and road reagents. After washing the body is dried and proceed to degreasing. This stage is critical: any traces of oils, silicone or wax will lead to peeling of paint or the appearance of craters ("fish eyes"). They use degreasing. White Spirit Or special antisilicones.
Dismantling of hinged elements - handles, mirrors, moldings, headlights - greatly simplifies the process of painting and avoids sharp color transitions on the edges. If it is impossible to remove the detail, it is carefully pasted with paint tape and covering material. It is important to use high-quality Scotch, which will not leave traces of glue in the sun and will not let the paint under the edges.
How to remove persistent bitumen stains?
To remove the ingrained bitumen, use special cleaners based on citrus oils or kerosene. Apply the product to the rag and gently rub the stain, trying not to smear it on a clean surface. After removing bitumen, be sure to re-degrease.
After degreasing, you can not touch the surface with your hands. Even the fingers of the finger can cause a defect. You should work in nitrile gloves. If there are deep scratches to metal on the body, they must be cleaned to pure metal to stop corrosion.
Spattering and grinding of the surface
Aligning the geometry of the body is the most time-consuming stage. To eliminate dents and deep irregularities is used putty. There are several types of it: universal, with fiberglass (for deep dents) and finish. Apply the material in thin layers, allowing each to dry according to the instructions. Overheating of the putty when drying can lead to its cracking in the future.
Grinding is carried out with abrasives of different grains. Start with a coarse grain (P80-P120) for rough alignment, then move to P180-P240. Finish grinding under the ground is performed with the abrasive P320-P400. It is important to use a grinding bar or a machine so as not to create “waves” and pits that will appear after painting. You can control the evenness by holding your hand across the grinding direction.
After each step of grinding, the body must be blown with compressed air and degrease again. Dust clogged in the pores of a putty or old varnish should be completely removed. For hard-to-reach places, special brushes and purge guns are used.
☑️ Training checklist
Grounding: Creating an adhesive layer
The soil performs two main functions: provides adhesion (clutch) of paint with metal or putty and aligns the surface microrelief. For bodywork, two-component acrylic soils are most often used. They fill the risks of grinding and create a monolithic surface. Before applying the soil must be thoroughly mixed and, if necessary, filtered through a funnel with a grid.
Apply the soil should be spray gun with a duse of 1.6-1.8 mm. The pressure at the outlet of the torch is regulated in the range of 2.5-3.5 atmosphere. The soil is applied in 2-3 layers with interlayer drying for 10-15 minutes (depending on the temperature and type of material). The first layer is made thin ("supple") to avoid undermining the putty with a solvent. The following layers are applied more abundantly, achieving a uniform matte coating.
After drying completely (usually 24 hours at room temperature), the soil is polished. If you plan to paint with metallic, use the abrasive P400-P500. Under solid (single-colored paint) you can use P600. Grind carefully so as not to wipe the soil to metal, especially on the ribs and sharp faces.
The quality of the final coating directly depends on the quality of soil preparation. Any risk left by a large abrasive will manifest itself after the paint shrinks.
Technology of enamel and varnish application
The most important moment is the application base-enamel. The paint must be diluted with the recommended solvent in the proportion specified by the manufacturer (usually 10-15%). Viscosity is checked with a viscometer. Applying begins with hard-to-reach places and edges. The gun is held perpendicular to the surface at a distance of 15-20 cm. The speed of movement of the hand should be uniform, about 40-50 cm per second. The overlap of the strips (torches) is 50-70%.
The base is applied in 2-3 layers. The first layer is thin, binding. The second is the main, covert. The third is a control, to align the tone and eliminate possible bands. Between the layers, an exposure of 10-15 minutes is required to evaporate the solvent (surface matte). If you hurry, you can get a “boiling” or loss of gloss.
After drying the base (usually 20-30 minutes, but no more than 24 hours) apply varnish. The lacquer gives depth of color and protection. It is applied in 2-3 layers. The first layer is thin, rubbing. The second one is wet, glossy. It is important not to pour the varnish, otherwise the leaks form. To work with the varnish, the duse is often changed to a smaller one (1.3-1.4 mm) or the same gun is used, thoroughly washing it.
| Parameter | Basic enamel | Acrylic lacquer | grunt |
|---|---|---|---|
| Diameter of a duo | 1.3. - 1.4 mm | 1.3. - 1.4 mm | 1.6. 1.8 mm |
| Pressure (atm) | 2.0 - 2.5 | 2.0 - 2.5 | 2.5 - 3.5 |
| Number of layers | 2-3 | 2-3 | 2-3 |
| Interlayer drying | 10-15 minutes | 10-15 minutes | 10-20 minutes |
What do you do if you get a varnish leak?
If the flow is small, let the varnish dry completely (preferably a day), then gently cut it with a blade and grind with an abrasive P1500-P2000 until the surface is leveled. After that, polish the site. Do not try to remove fresh flow with a cloth - you will spoil the entire element.
Painting defects and methods of their elimination
Even experienced craftsmen sometimes have defects. Shagrens ("orange peel") occurs due to too viscous paint, high pressure or the wrong temperature. Small pearls are removed by polishing, deep - grinded and repainted. Craters ("fish eye") are caused by silicone or oil on the surface. Removed only by a complete repainting of the element after thorough cleaning.
The mattiness or “milkiness” of the varnish often indicates increased humidity in the room or the use of a quick solvent in cold weather. Sometimes polishing helps, but in serious cases, removing the layer and re-application are required. The leaks are the result of too fluid material or slow movement of the hand.
⚠️ Warning: Never use abrasive polymer until 2-3 weeks after painting. The polish must finally polymerize (“stand up”), otherwise you risk rubbing it to the base or leaving cloudy spots.
To eliminate small defects (dust, small shaver) apply abrasive polishing. Pastes of different grains are used: first coarse (cutting) to remove the defect, then fine (finishing) to restore gloss. Polishing is performed with a polishing machine with circles of wool or foam, controlling the heating of the surface.
Frequently Asked Questions (FAQ)
How long does the paint dry in the garage?
The drying time depends on the temperature and type of materials. Basic enamel dries "on the stick" for 15-30 minutes. The lacquer gains primary hardness after 2-4 hours, but complete polymerization takes 7-14 days. During this period, it is not recommended to wet the car or expose it to active loads.
Can I paint my car in the winter in an unheated garage?
It's not recommended. At temperatures below 15°C, the materials do not flow properly, leading to defects. In addition, condensate falling on the cold metal will destroy the adhesion. The garage must be heated before and during work.
What compressor is needed to paint a car?
For high-quality painting, you need a compressor with an inlet capacity of at least 350-400 liters per minute and a receiver of 50 liters. It is important that it provides stable pressure without pulsations. For working with a water-oil separator and a dehumidifier, the requirements for the volume of the receiver increase.
Do I need to remove the old paint completely?
Not if the old coating is strong, not swelled and has no corrosion. It is enough to wrap it with abrasive P400-P500, degrease and prime. Full removal of paint to metal is required only in the presence of serious defects or corrosion.