The presence of red dots or deep corrosion on the car body requires immediate application of acid soil in the can, since this composition chemically binds to metal oxides, stopping further destruction. Unlike the acrylic analogues, phosphoric acidThe rust contained in such aerosols converts the rust into a strong protective layer, preventing oxygen from reaching the surface. The use of a finished aerosol significantly accelerates the process of local repair, allowing the master to avoid the stage of mixing components in proportions, which is critical when working with small areas or in the field.
Application acid-primer in aerosol packaging is justified in restoring the thresholds, arches and bottoms, where there is a high probability of hidden corrosion foci. A thin layer of such soil creates an adhesive base, to which any subsequent paint material adheres perfectly. However, it is important to understand that this composition is not a finishing surface and requires mandatory overlapping. epoxy Or putty to completely insulate the metal from moisture.
The choice of a quality product in a can can avoid common mistakes associated with violation of the technology of mixing two-component systems. The finished mixture in the aerosol already contains the necessary solvents and activators in the correct balance. This makes the metal processing process more predictable, especially for those who do not have professional painting equipment and work in a garage setting.
Chemical composition and principle of action of reactive soil
The basis of any acid soil is polyvinylbutyl alcohol Orthophosphoric acid, which reacts with iron oxide. When applied to the metal, a passivation process occurs, as a result of which the surface is covered with the thinnest insoluble film. This film serves as a barrier to block electrochemical reactions necessary to continue the rusting process. In aerosol cylinders, components are often separated or stabilized with special additives that allow the mixture to be stored for a long time.
Key feature jet-soil It is their ability to penetrate into the microscopic pores of the metal, which can not reach mechanical cleaning methods. Acid displaces moisture and air, providing maximum adhesion. It is important to note that the chemical reaction takes place even on a slightly moist surface, which makes such compounds indispensable for emergency repair in conditions of high humidity.
⚠️ Attention: Acid soil is a toxic and aggressive chemical. Work should be carried out only in a well-ventilated room using personal protective equipment for the respiratory and skin organs.
Modern formulations in cans often contain additional anticorrosion additives that enhance the protective properties of the coating. zinc or other active metals in the composition create the effect of cathode protection, sacrificing themselves for the sake of preserving the body. Understanding the chemistry of the process helps you choose the right drying time and application conditions to achieve the best result.
Technology of two-component systems
In classic two-component soils, the mixing of the base and activator occurs immediately before application. In aerosols, this process is often already performed by the manufacturer, or activation occurs when sprayed due to a special valve design, which guarantees the stability of the reaction throughout the life of the balloon.
Advantages of using aerosol acid soils
The main advantage of using soil in the can is the mobility and speed of surface preparation. You don’t need to buy individual components, weigh them on scales and risk misproportion. Ready. spray allows you to process hard-to-reach places where it is difficult to reach with a spray gun, for example, the inner cavities of doors or spars, using special extension nozzles.
In addition, the aerosol packaging provides perfect tightness until the moment of use, excluding oxidation of the mixture in the can. This is especially important for acidic compounds that lose their properties when in contact with air. Once the work is completed, the cylinder can be closed, saving the residues of the material for the next time, although for acid soils this is less relevant due to their low cost per repair.
- 🚗 Instant readiness to work without mixing components.
- 🛡️ High penetrating ability in microcracks of metal.
- 💨 Uniform spraying of the fine fraction.
- ⏱️ Fast drying time, allowing you to continue working in 15-30 minutes.
Economic feasibility also plays an important role. Buying a 400-500 ml can of cans is much cheaper than buying a liter can of professional soil and solvent, especially if it is a one-time repair. acid spray It is the best solution for car owners who value their time and quality of results.
Application technology: step-by-step instructions
Before starting work, the surface must be carefully prepared. The metal should be cleaned of loose rust, dirt, oils and old paint coating. To do this, use a P80-P120 grinding paper or sandblaster. After mechanical cleaning, degrease the surface with a special composition to prevent silicones or fats from getting under the soil layer, which can lead to detachment.
Shake the can for 2-3 minutes to evenly distribute the components inside the container. The temperature of the cylinder and the surface to be treated shall be in the range from +15 to +25°C. Put it on. acidic thin layers from a distance of 20-30 cm, making breaks between layers in 5-10 minutes to evaporate the solvent. Do not try to create a thick coating in one pass, this will lead to leaks and a decrease in adhesion.
☑️ Quality control of body preparation
After the final layer is applied, allow the coating to dry for the time specified by the manufacturer on the package (usually 15-30 minutes). The surface should acquire a matte shade and stop being sticky. Only then can you start applying. epoxy Or polyester putty. Direct application of paint on acid soil is not recommended, as it can react with the components of the enamel.
⚠️ Warning: Never apply acid soil with a thick layer. Excess thickness can cause the acid to not fully react with the metal and remain aggressive, causing corrosion under the coating in the future.
Compatibility with other materials and coatings
The most important aspect of body repair is the correct sequence of application of materials. Acid soil is perfectly combined with most types of putty, but there are nuances. Polyester putty can be applied directly to the dried acid layer, whereas some types of epoxy soils may require prior compatibility testing.
It is strictly forbidden to apply acid soil over epoxy. Epoxide creates a sealed film through which the acid will not be able to penetrate the metal, and there will be no sense in its use. In addition, the acidic medium can destroy the adhesion of the epoxy layer. The correct order always looks like this: bare metal -> acid soil -> epoxy soil / putty -> acrylic soil -> paint.
| Materials of coating | Compatibility | Recommendations |
|---|---|---|
| Polyester putty | Complete. | Apply after full drying of acid |
| epoxy | Complete. | The perfect ligament for insulation |
| Acrylic enamel | Limited. | An intermediate layer of soil is required |
| Alkyd paint | Low. | High risk of detachment and defects |
When working with alkyd You have to be especially careful. Residual acidity can cause a saponification reaction, which will lead to bloating and loss of color of the finishing surface. Always use an insulating layer of acrylic filler soil between the acid base and finish paint.
Review of popular grades of acid soils in aerosols
The automotive chemicals market offers a wide range of products from various manufacturers. The leaders of the segment are considered brands Novol, Motip and Body. Company products Novol (Wash Primer series) has established itself as a professional remedy with a high content of zinc and excellent adhesion. The bottles are equipped with high-quality sprayers that give a smooth torch.
Brand Motip Offers affordable solutions for amateur use. Their acid soils dry quickly and lie well on a complex terrain. Body 96 It is also a popular choice, featuring good cover and reliable protection against corrosion. When choosing, you should pay attention to the date of production, since the shelf life of chemical reagents is limited.
- 🏆 Novol Wash Primer - the choice of professionals, high chemical resistance.
- 🎨 Motip Dual Color – easy to use, good equipment.
- 🛡️ HB Body 96 – Balanced price and quality, fast drying.
- 🔧 Reoflex is a domestic analogue with decent characteristics.
Criterion of choice: When buying, be sure to check the date of manufacture at the bottom of the cylinder. Overdue acid soil can lose its reactive properties or, conversely, become too aggressive due to a violation of the stability of the mixture inside the cylinder.
Common mistakes when working with acidic compounds
One of the most common mistakes is to apply soil on a poorly prepared surface. If there is a scalp, a large-scale rust or oil left on the metal, acidic It will not be able to create a reliable connection. As a result, after a short time, the coating will begin to peel off along with the rust, and corrosion will continue to develop under the paint layer.
Another common mistake is ignoring the time of interlayer drying. Attempting to speed up the process by applying the next layer of "wet" or using a building hair dryer to dry the acidic can lead to boiling of the solvent and the formation of pores. Phosphoric acid It must have time to react with the metal, and the solvent - completely evaporate.
⚠️ Do not grind acid soil "dry" without a respirator. The resulting dust contains reaction products of acid and metal, which are harmful to the lungs and can cause allergic reactions.
Also, the masters often forget about the protection of adjacent body elements. Acid soil has a high penetrating ability and can leak under seals or into gaps, causing hidden corrosion there. Always use high-quality paint tape and cover film to insulate areas that are not subject to treatment.
Expert advice: If you accidentally poured acid soil rubber seals or plastic parts, immediately wash it with plenty of water and soap. Acid can eat away at rubber and make plastic brittle.
Frequently Asked Questions (FAQ)
Can I paint directly on acid soil?
No, you can not directly apply finishing paint (especially acrylic or alkyd) to acid soil. The acid base can react chemically with the paint components, resulting in color change, bloating, or loss of adhesion. Be sure to cover the acid layer with epoxy soil or putty, and then with acrylic filler.
How much does the acid soil dry in the can?
The surface drying time is usually 10-15 minutes at a temperature of +20 ° C. However, for full polymerization and readiness to apply the next layer (surfing or overlapping), it is recommended to wait 30-60 minutes. The exact time is always indicated in the instructions on the specific cylinder.
Do I need to grind the acid soil before applying the putty?
As a rule, acid soil creates a very thin film, which is not recommended to grind to metal, so as not to disturb the protective layer. It is enough to slightly pass the surface with abrasive P240-P320 to improve adhesion (create risk) or simply degrease if the manufacturer of the putty allows application without grinding.
Can I apply acid soil to galvanize?
Yes, acid soils are great for preparing galvanized surfaces. The acid helps create an adhesive bridge between smooth zinc and subsequent coating layers that might otherwise detach. This is a standard procedure for repairing modern cars.
What to do if the spray stops spraying?
The nozzle must have dried up. Turn the balloon upside down and press the sprayer for 2-3 seconds so that the residual pressure pushes the remnants of the mixture out of the channel. If this does not help, you can carefully remove the nozzle and wash it with a solvent (for example, 646 or acetone).