Self-painting is a process that requires not only patience but also a deep understanding of the chemical reactions that occur with paint coatings. When you decide lacquerYou take responsibility for the durability and appearance of the body for many years to come. Mistakes at this stage can be costly, as fixing varnish defects often requires a complete repainting of the item.
Modern technologies allow you to achieve a result that is not much inferior to the factory, even in garage conditions. However, for this it is necessary to strictly observe the temperature regime, humidity and time intervals of drying. In this article, we will break down each step, from surface preparation to final polishing, so you can get the job done in a quality manner.
The main enemy of quality lacquering is dust and haste. If you are not ready to keep the room clean and take enough time to dry each layer, the result may be disappointing. Two-component varnishes, which are most often used in auto repair, irreversibly harden after mixing with a hardener, so the right to error in the master is almost there.
Selection of materials and preparation of tools
The first step to success is the right choice. car-varnish. In the modern market are acrylic, polyurethane and alkyd compositions. For professional results, it is recommended to use high dry residue polyurethane varnishes (HS or UHS), which give a deep shine and excellent scratch resistance. Cheap aerosol cans are suitable only for spot repair of small chips, but not for full painting of the body.
In addition to the varnish itself, you will need a quality hardener and, if necessary, a solvent to adjust the viscosity. The proportions of mixing components are critical: a violation of the ratio indicated on the bank will either lead to uncolding of the coating or to its excessive fragility. Also do not forget about the filter funnel, through which you must necessarily pass the mixture before pouring into the spray gun.
The tools should be clean and serviceable. Krascopult with a duse of 1.3-1.5 mm is ideal for applying varnish. The use of dirty or faulty equipment is guaranteed to lead to the appearance of “shagrene” or spit on the surface.
- 🎨 High-quality two-component lacquer (HS or UHS class).
- ⚗️ Original hardener, selected for the temperature regime in the room.
- 🔫 Correct spray gun with a clean duse of 1.3-1.5 mm.
- 🧣 Respirator with carbon filters and protective gloves.
⚠️ Warning: Never use acetone-based solvents or aggressive diluents to clean the spray gun after working with polyurethane varnishes unless recommended by the manufacturer. The residues of such solvents in dusa channels can react with the varnish and cause its curling directly during painting.
Do not skimp on personal protection equipment. The vapors of solvents and hardeners are toxic, and the ingress of varnish components on the skin can cause a severe allergic reaction or chemical burn. Work should only be in a well-ventilated room, preferably with a forced hood.
Preparation of the surface for varnishing
The quality of the final coating depends on 80% of how the surface was prepared. The polish is transparent, and it will not hide, but only emphasize all the defects of the base. If you apply varnish to fresh base-enamelMake sure it is completely dried and matte, but not overexposed. The optimal time for varnishing the base is from 20 minutes to 24 hours, depending on the recommendations of the paint manufacturer.
If the enamel is overstuffed (for example, left unprotected for a week), its surface may become oxidized or covered with microscopic dust, which worsens adhesion. In such cases, before varnishing, the base must be gently pasted with a fine abrasive (P1000-P1200) or treated with a special antisilicone to remove contamination and create micro scratches for clutch.
Degreasing is a critical stage. Use special degreasers (antisilicons) in two stages: the first wipe removes the main contaminants, the second (conducted with a wet, but not wet wipe) removes the residues. Movements should be reciprocal so as not to smear the fat on the surface.
☑️ Checklist of preparations
After degreasing, it is strictly forbidden to touch the surface with your hands even with gloves, since microparticles of dust may remain on them. Immediately before painting, walk through the detail with an antistatic or sticky napkin to remove settled dust.
How to check the readiness of the base for varnishing?
Carefully apply your finger in a clean glove to an inconspicuous area or the edge of the part. If the finger does not get dirty and there is no trace, and the surface is dry and matte to the touch - you can varnish. If you feel sticky or have a print, you need to give the base more time.
Lacquer technology
The process of applying varnish requires calmness and confident movements. Mixing the varnish with the hardener according to the instructions, let the mixture stand for 5-10 minutes to exit the air bubbles. The first layer is applied with a thin, so-called "dust" layer. Its task is to create primary adhesion and to link possible dust residues.
The second and third layers are the main and form the coating body. They should be applied "wet wet", withstanding interlayer drying (flash period) in 10-15 minutes. The polish should spread, forming a glossy surface, but not flow. The distance from the duse to the surface should be 20-25 cm, and the movements of the spray gun - to block the previous passage by 50%.
It is important not to try to fill everything at once – this is guaranteed to lead to leaks. It is better to make three thin but saturated layers than one thick one. Lacquer thickness In the end, it should be about 50-60 microns.
| Parameter | 1st layer (Pripyl) | 2nd layer (Main) | Layer 3 (Finished) |
|---|---|---|---|
| Thickness | Thin, translucent | Saturated, wet. | Saturated, glossy |
| Pressure. | 2.0 - 2.2 atm | 2.2 - 2.5 atm | 2.2 - 2.5 atm |
| Suit | 10-15 minutes. | 10-15 minutes. | Complete polymerization |
When applying the finish layer, you can add 5-10% solvent for better spreadability and shine, if the temperature in the chamber allows. Watch the angle of inclination of the spray gun: it should always be perpendicular to the surface, otherwise there will be bands of different thicknesses.
Keep the spray gun strictly perpendicular to the surface throughout the movement of the hand. The tip at the beginning or end of the passage will lead to uneven application and different tone of shine.
Drying and polymerization of coatings
Proper drying is the key to the hardness and durability of the lacquer. There are two main ways: natural drying at room temperature and forced (infrared lamps or in the chamber). Natural drying takes longer, but is less risky for beginners, as it eliminates the risk of boiling the varnish.
If you use IR drying, you can start heating only after the varnish sits out for 15-20 minutes at room temperature, so that the solvent escapes. The sharp heating of fresh lacquer will lead to the formation of bubbles and craters, as the solvent will begin to boil inside the already grasped film.
Complete polymerization (final curing) takes 7 to 14 days. During this period, the lacquer gains its maximum chemical and mechanical resistance. Before the expiration of this period, it is not recommended to wash the car with aggressive chemicals or expose the body to heavy loads.
⚠️ Note: Do not try to accelerate drying with a household hair dryer or fan heater. Uneven heating will lead to clouding of the varnish (the effect of “bleach”) and the appearance of internal stresses, which over time will cause cracks.
The temperature in the room should be stable. Sharp temperature changes or drafts during drying can spoil the appearance of the coating, creating defects of the type of “orange peel”.
Defect elimination and polishing
Even experienced craftsmen on the surface may remain small defects: dust, shashashare or small flows. They can be eliminated only after the varnish is completely dryed, but before the active operation of the car begins. To remove dust, grinding with abrasive P2000-P2500 is used.
Polishing is the final stage that gives the coating a mirror shine. The process is divided into two stages: restorative polishing (removal of the drawings from grinding) and finishing (providing depth and gloss). Use a polishing machine with adjustable speed so as not to overheat the varnish.
The work will require polishing circles of different rigidity and polishing with abrasiveness P1500 and P3000 (or their finishing counterparts). Movements of the machine should be cruciform, without strong pressure, so as not to wipe the varnish to the base.
- 🌀 Grinding paper of P2000 and P2500 gradation for the removal of shavels.
- 🧽 The medium-severity polishing circle for the first stage.
- ✨ Finish polishing circle for maximum shine.
- 🧴 Polishing with varying degrees of abrasiveness.
The main rule of polishing is not to overheat the surface. If the varnish becomes too hot, it will begin to reach for a circle or become cloudy, which will require resurfacing.
Frequently Asked Questions (FAQ)
How long after painting can I wash the car?
Washing the car using shampoos and active water exposure is recommended no earlier than 7 days after painting. During this time, the varnish will gain sufficient hardness. For the first couple of weeks, it is best to avoid automatic washers with hard brushes.
What to do if the varnish leaks during application?
If the leak is detected immediately, it can be carefully removed with the edge of the napkin, but there is a high risk of spoiling the surface. It is better to let the varnish dry completely (at least 24 hours), then grind the flow of the abrasive P2000 in a level with the general plane and polish this area.
Can I apply the paint to the old paint without removing it?
Apply a new varnish on the old one can only be if the old varnish does not have detachments, deep cracks and holds well. The surface must be wrapped with an abrasive P1000-P1200 and degrease. If the old lacquer began to peel off ("rag") when grinding, it must be completely removed.
Why did the varnish become matte after drying?
Lacquer turbidity is most often caused by high indoor humidity, drafting, or using a too fast solvent at low temperature. Also, the cause may be insufficient drying between the layers, when the solvent remained in the lower layers and came out, disrupting the structure.
Do I need to dilute the lacquer before applying?
Finished kits (varnish + hardener) usually have the correct viscosity and do not require dilution. Add a solvent only if the room is very hot (above 25 ° C) or if you use a technique that requires a more liquid material. Excess solvent reduces the resistance of the coating.