How to deal with rust on a car body

3 real ways to save a car if the body has already begun to rust

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An ominous red spot on the fender, bubbles under the paint at the bottom of the door, suddenly wet floor mats after driving through puddles - all these are signs that the car is already actively rusting. If you start this process, then in just a few years the body will become rotten, for the restoration of which you will have to pay handsomely.

If you look at it, the struggle of car owners with corrosion is a hopeless cause. Despite modern coatings and new alloys, frequent contact with water and aggressive chemicals causes the car body to undergo air oxidation. Rust is especially dangerous for older cars from the 1970s, when car factories used untreated sheet steel. From the appearance of the first stains on the surface to through holes in the body, in fact, only a few years could have passed.

Isolated spots of rust

First of all, corrosion forms in scratches and paint chips. Also, the protective properties of the paintwork are negatively affected by ultraviolet radiation from the sun. And in the event of an accident, the impact sites and bends of body parts need to be “treated” as quickly as possible.

Repairing surface rust is easy. To do this, use an abrasive wheel or sandpaper to remove the paint layer in the damaged area until bare metal is visible. Traces of rust must be completely removed, since even the smallest “dots” will become new centers of corrosion, and the repair will thus go down the drain. The bare metal is primed and then painted.

And to provide additional protection to the car, it would be useful to cover the body with a special synthetic wax.

Large rust spots and bubbles

Body parts made of steel should always be coated with a coat of paint. Even the presence of a chromium or nickel coating does not protect against corrosion. If rust spots do appear, they will grow to the size of spots. It’s even worse if the car drives on snowy roads that are sprinkled with salt. Therefore, it is not surprising that in large Russian cities cars rot very quickly.

When steel turns to iron oxide (rust), it expands significantly, causing blisters underneath the paint. The surface is already uneven and very rough. To remove these irregularities, use a wire brush, an abrasive wheel, and then sandpaper, resulting in shiny metal. Next, as in the previous case, apply a layer of primer and paint.

Through holes

After prolonged aggressive exposure to steel, holes form in body parts. Automakers are actively fighting this, but it all comes down to money. Aluminum or magnesium components are too expensive to replace steel. And anti-corrosion alloying additives (nickel, chromium, molybdenum, titanium) are also limited in use, since they are an order of magnitude more expensive than steel.

As you can see, complete rotting of the car body is a matter of time. But what should the driver do if the power plant is working quite normally, but the rust has eaten right through the bottom and wings? The only way out is to replace parts. As a rule, damaged areas are cut straight out in whole pieces and discarded. To replace them, similar ones taken from so-called “donor” cars (they are found at disassembly sites) or repair spare parts are welded in. The last option, despite the apparent simplicity of the solution, is not always good. And all because these parts are stamped in China and Taiwan, and the cheapest metal is used.

Rust protection

When the car is moving, sandblasting is constantly carried out on its bottom and wheel arches. Therefore, only regular inspection and repair of emerging rye stains will save you from big expenses in the future. For this, various compounds are used (bitumen mastics, Movil), which are applied in a thick layer directly to the bottom. It’s just worth noting that their effectiveness is quite questionable. The author of the website Nobate.ru, while doing body repairs, came across a situation where the bottom rotted, being covered with a layer of “protection”. As a truly effective remedy, we can recommend regular car washing to clean the body and underbody of dirt, salts and dirt, and also check the drainage holes through which rainwater flows. It would be a good idea to fill the internal cavities of the body, including the side members, with oil, which provides significant protection. And the bottom of the car should be treated with gun fat. True, its layer will have to be updated regularly.

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Rust is not a death sentence

In the modern world, fighting rust is no longer so difficult, even if you do it on your own, without the involvement of specialists

As long as cars are made of metal, they will rust, despite galvanizing and priming. In the modern world, fighting rust is no longer so difficult, even if you do it on your own, without the involvement of specialists.

A car rusts most when it is standing, especially if it is not in the open air, but in a cold, windproof box. When driving and on the street, the car body is blown and therefore remains more or less dry.

In this material we will talk about different methods of combating corrosion - “old-fashioned” and modern. There are three of them: passive, active and transformative.

The first, passive, is the old “old-fashioned” method, in which problem areas are treated with various kinds of mastics and anticorrosives. The second method appeared with the development of chemical industry technologies: its essence is to periodically treat the body with various kinds of protective agents that are invisible, but at the same time form a fairly wear-resistant film on the surface. The third method is the most interesting and is applicable when the body has already begun to bloom: compounds applied to the rust transform it into soil, which perfectly protects the preserved metal from further corrosion. There is a fourth method, which is often classified as active, but it is better to highlight it separately. This is electrochemical protection, cathodic. Each method should be described in more detail.

Passive way

It can be used on both a new car and a used car. You apply mastic or anti-corrosion agent to the clean bottom of the car, after first removing the plastic or felt protection of the wheel arches. The bottom must be clean and dry. The surface of parts of modern cars perfectly “holds” various types of anticorrosives, and modern mastics are very sticky. However, service and garage pros recommend additional primer. Some problem areas (niches, cavities and seams on the bottom, under the hood and in the doors) should be treated with a polymer anticorrosive agent or a multi-component aerosol based on a mixture of wax and resins. This old “old-fashioned” method has a number of significant disadvantages.

Firstly, it is very labor-intensive and you cannot use it outdoors: you need a garage with a pit. Secondly, every two years it is necessary to carry out preventive maintenance (lubricate, restore, redo in places), otherwise all the efforts of primary treatment will be in vain - in order to protect, the coating must last for many years, but it is washed off, exposing the metal. Therefore, the passive method is used less and less, preferring either the simpler active method, or relying on new developments: the transformative method and electrochemical protection.

Today, few people care about new cars in this way: the owner knows that the factory protection will last for his lifetime, and rust will become a problem for the second or even third owner. More often, additional anti-corrosion treatment is carried out on new domestic cars. For old times' sake. Or they do it carelessly shortly before resale in order to disguise the rot.

The passive method is more relevant on used cars. The process differs from what has already been described only in that before applying primer and mastics, it is necessary to remove existing rust. And here it is better to resort not to the services of sandpaper and white spirit, as in the old days, but to the third method - transformative.

Active method

Active protection is more suitable for a new car. These are various kinds of visible and invisible compounds and varnishes that are periodically applied to the body. It is better to spray a colored composition on the bottom, so that later it will be easier to determine whether it was washed off during use or not. And the paint coating, of course, is a colorless composition or varnish, which, in addition, will make it shine better. Before application, the body, again, needs to be cleaned and dried thoroughly. Under no circumstances apply these compounds to the radiator or engine parts - cooling will deteriorate and the belts will begin to slip. The main disadvantage of this method is not its fragility (for one season), but the fact that it will not protect really problem areas (hidden cavities and niches) from corrosion.

The active method includes treating the body with wax, as well as washing it with special anti-corrosion shampoos.

Transformative method

For many, this method has become a panacea in the fight against corrosion. It's simple, ingenious and doesn't require a lot of time, effort or money. One “but” is the appearance of the car. The fact is that the essence of the method is to treat already rusted areas with a special compound (rust converter). It is based on phosphoric acid, which turns the hated rust into a lead primer, onto which paint can be applied without additional surface treatment. First you need to carefully wipe off any remaining converter that has not reacted. You can do the treatment literally on the go, during stops for at least half an hour: anoint it, wait as long as indicated in the “Method of use” on the converter packaging, wipe off the residue and move on. Without subsequent painting, the car body will not look very aesthetically pleasing, but everything has its time. The main thing at the first stage is to stop corrosion.

Electrochemical protection

This method helps you forget about the appearance of rust on a new car and stop corrosion on an already rusty used car. For this purpose, a special electrical device is used - a cathodic protection station, which is installed in the engine compartment.

The fact is that the rate at which rust appears depends on the electrode potential of the metal. It is enough to shift the potential of the metal into the negative region and the corrosion process stops almost completely. Only the electrodes of the device rust, to which anodic processes are transferred (it is because of them that rust is formed), and only cathodic processes remain on the surfaces of the car, which do not lead to the formation of rust. By the way, galvanizing metal works in the same way - removing anodic processes from the surface. The effectiveness of this method is 99.7%. That is, rust will still appear, but not earlier than in ten years.

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Operation “Stop Rust”: ridding the car body of saffron milk caps and traces of rust on your own

A red scourge called rust plagues many car enthusiasts. The less protected the car body is from corrosion at the factory (galvanization), the more often the owners will have to make efforts to eliminate red spots. Moreover, it is undesirable to delay liquidation, since over time, damage to the metal only increases. As a result, in six months you will have to spend much more time and money than today. So, what will you need to remove rust and saffron milk caps with your own hands and how to remove them without harming the body.

Causes and places of rust on a car body

Rust is the oxidation of metal that occurs under the influence of air, water and static electricity. Therefore, the main reason for its occurrence is damage to the paintwork of the car body. Microcracks and physical damage allow air and moisture to reach the iron. The speed of the destructive impact will depend on the degree of protection of the body itself and the aggressiveness of the environment. This is especially true in winter, when many chemicals appear on our roads.

The above factors directly affect the shape, color and depth of corrosion. People call them differently: “saffron milk caps,” “bugs,” or simply “rusty spots,” but their essence is the same (only the degree of neglect varies). A single spot of rust is easier to deal with than many small red spots. The latter usually indicates poor quality metal or unsuccessful body repairs. The total processing area will be larger. Moreover, these points often spread in depth rather than in breadth. Blistering of the paint also signals the need to remove corrosion that has begun to develop under the paintwork.

The most common places for bugs and rust spots (photo)

Rust progresses well in places where there is increased exposure to foreign objects: sand, dirt, stones. The hood suffers from small stones from the tires of other cars, the wheel arches from their own “emissions” (by the way, wide non-standard tires or rims contribute to greater damage). The thresholds of the car are also one of the first to rot due to the close proximity to the “aggressive environment”, plus unsuccessful exits from curbs aggravate the situation.

How to delete: options

We have become acquainted with the causes and places, let's move on to methods of correct elimination. There are two methods that differ in the way they remove rust:

1. Mechanical - cleaning, priming, puttying, painting.
2. Chemical - rust converters or kits for galvanizing metal.

You cannot do without the first method if the rust is strongly ingrained into the metal.
Then it is necessary to completely eliminate traces of corrosion until pure iron (ideally shiny) remains. To do this, you may need additional tools and resources, which we will discuss below in step-by-step instructions. The second option is suitable for hard-to-reach places.
These could be curves on the bottom of the car or the inside of the arches, which are difficult to process using mechanical means. Depending on the product, rust after chemical treatment can turn into foam (you need to rinse with water and dry the surface) or harden and become covered with a protective layer suitable for painting. Be sure to read the instructions and recommendations for the use of chemicals before purchasing. Before starting work, try to assess the extent of damage to the body and assess whether you can etch the damage with chemicals alone. For a positive result, it is necessary that “live” iron remains after the initial cleaning. If there are through holes or the final thickness of the metal after processing is too small, then more serious body repairs will be needed, that is, initially all these areas will need to be repaired using welding or putty with fiberglass.

Reviews of the most popular tools and methods

The ideal option is orthophosphoric acid. Apply a thin layer to the camelina, wait 10–30 seconds, wipe dry with a cotton pad. It eats up rust and forms a phosphate film that is not afraid of water and is inert.

Maxim Leonov

http://avto-flot.ru/blog/kak-udalit-rjavchinu-s-kuzova-avtomobilya-i-ostanovit-ee-rasprostranenie.html

I already tried orthophosphorus - this is still an old-fashioned method, I processed what I cleaned. (As far as I know, all these inhibitors and converters are what it is, only in multi-colored bottles). Indeed, almost cleaned surfaces, this rubbish gets rid of rust residues. But untouched, so to speak, terry thickets of corrosion do not particularly react to it. So, they sizzle a little, darken, turn pale and remain in place.

Saf

http://forums.drom.ru/4×4/t1151267034.html

Nowadays, people no longer burn at the stake for the magic of transforming rust into pure and white metal, but a miraculous transformation does not happen either. And the zealous body workers continue to sand, etch, putty, treat with filler... And that’s why - because you can’t pull it out without difficulty... It’s impossible, you know, to rub it with a cloth and for it to become overgrown - it doesn’t happen. So go ahead, Shura, go ahead...

Zaika 2106

https://forum.auto.ru/chemistry/22048/

Mechanical method (step by step instructions)

If you follow the instructions and take your time, you can forget about rust on your car for 1-2 years (at least in the treated areas). The work is carried out in stages:

1. preparing everything necessary;
2. initial cleaning of the damaged part of the body;
3. degreasing and priming;
4. painting and varnishing.

DIY Tools and Supplies

To work you will need:

• grinding tool and sandpaper,
• rust converter,
• solvent,
• anti-corrosion primer,
• paint to match the body color and clear varnish (in cans),
• if necessary, two-component automotive putty (with hardener).

1. You can fight rust using a sandblaster, an angle grinder with a grinding wheel, a drill with a special attachment, or the trivial, but always accessible, method - with your hands and sandpaper.

   

   The work can be done manually or using special machines

   The main thing is to work carefully and slowly. There should be no deep scratches or rough transitions. Try to get a polished surface with smooth gradients.

   

   A grinder is often included in a car enthusiast’s arsenal.

   

   The damaged paintwork is removed layer by layer and subsequent damaged areas are processed.

   

   The longevity of the result depends on the thoroughness of the work.

   

   Universal types of putty, oddly enough, are not suitable for all types of car bodies

   It is applied in several layers and each one is sanded until smooth. Your goal is to fill all the depressions and achieve a perfectly smooth surface when the work is completed.

   

   To work, you will need several types of sandpaper.

   

   Do not skimp on protective equipment, especially if you are doing the job for the first time.

   Film, newspapers and masking tape are perfect for this. If you work outside, be sure to consider the direction of the wind.

   

   Make sure that dust and other abrasive particles do not fall on the treated surface.

   

   Painting work requires minimal skills!

   

   The result is not always the same as in the photo; it is often necessary to modify and eliminate flaws

   A good way to remove and repair rust on a car door (video)

   Do-it-yourself chemical way to get rid of corrosion

   The chemical method differs only in the initial stage - cleaning the part from rust. According to reviews from manufacturers, these substances are able to eradicate rust, stop its further spread and do not damage the iron itself (unlike “sandpaper”). Application is very simple - apply the product to the rusty surface for 30-40 minutes, then wipe with a cloth or rinse with water. But to get a nice, smooth surface you will still have to clean, putty and polish (except for the initial stages of corrosion).

   

   Some funds are available to motorists even with the most modest budget

   There are kits on sale that allow you to independently apply a protective layer of zinc to the car body. The kit already contains a solution for removing rust and applying a protective layer, as well as an electrode with a zinc tip. This process is electrochemical, so a connection to a battery is required.

   

   The kit includes liquids and all necessary working tools

   How to remove “saffron milk caps” and “bugs”

   Many people want to believe that if rust has just appeared and the lesions are small, then they can be eliminated with some miracle remedy. Unfortunately, this is impossible in principle. The rust that appears on the surface of the paintwork is like the tip of an iceberg; the main damage is deep inside.

   There are products on sale that will help remove the red color from the body. For example, there is Anti-Rust paste - it removes red spots quite quickly and well. This is the same rust converter that we discussed above. It eliminates the visible signs, but not the source itself. Such manipulations usually last for 2–6 weeks (depending on weather conditions), and they are most often used immediately before selling the car.

   

   Small “bugs” sometimes cause big problems for the car seller!

   If you want to get rid of the problem in the long term, then you cannot do without physical intervention. It is necessary to stop the access of air and moisture directly to the metal. Theoretically, you can prolong the effect of the paste if, after treatment, you cover the damaged area of ​​the body with clear varnish. But it will work if the converter has managed to remove all the rust. In most cases, this does not happen, since the depth of penetration of the product is small.

   

   Unfortunately, it will not be possible to hide damage for a long time only with the help of paste.

   Vehicle prevention and protection

   Tools available to every motorist, but which most of them ignore, will help you avoid the work done:

   • regular car washing, even in winter (additional waxing increases protection against aggressive environments);
   • regular inspection of a clean car (in the initial stages it is much easier to fix the problem);
   • wheel arch liners and mudguards on all wheels (will keep the paintwork presentable for much longer);
   • anti-gravel film on the hood and part of the roof above the windshield (an alternative is a “fly swatter”);
   • anti-corrosion treatment of the bottom of the car.

   The work of eliminating “bugs” and “saffron milk caps” is within the power of everyone. But for a good result it will take scrupulousness and time (especially the first time). Think about whether you are able to prevent such sources of trouble. Advanced corrosion leads to expensive body repairs without guarantees. Take care of your car, and it will reciprocate.

   DIY car corrosion control

   The fight against car corrosion often causes a lot of problems for its owner. For this, three main methods are used - passive, active and electrochemical, but each of them has its own advantages and disadvantages. Most often, corrosion is removed using special means. And for preventive purposes, a protective film is glued to the bottom, body thresholds and other hidden places or treated with mastic. There are also other preventive measures, which we will talk to you about later.

   Causes of corrosion

   First, let's figure out why corrosion processes occur. The fact is that there are four types of corrosion of metal surfaces - electrochemical, chemical, hydrogen and oxygen. In the context of rusting of an automobile body, only the first two types occur.

   Electrochemical corrosion occurs due to the fact that two materials with different reducing properties interact through an electrolyte (any non-distilled water is such). Since iron has low reducing properties, it is significantly susceptible to rusting. Chemical corrosion occurs due to the interaction of the metal surface and a corrosive environment. The latter role can be played by oxygen at high temperatures. Understanding the essence of the emerging processes gives us the basis for searching for methods to combat corrosion.

   Types of corrosion control

   There are two main ways to protect a car body from corrosion. The first is barrier protection. It does not allow physical interaction of the surface of vulnerable metals with the external environment. This is expressed in the use of paint and varnish coating and various mechanical means and protection. The second is tread protection. An example of this is galvanizing, because zinc has a more negative potential than iron. Accordingly, if you connect them, then in such a pair the iron will be reduced and the zinc will corrode. However, since there is an oxide film on the surface of zinc, this process occurs very slowly.

   As mentioned earlier, there are three main types of car corrosion control:

   Corrosion Removal Brushes

   1. Passive.
   2. Active.
   3. Electrochemical.

   The passive control method involves the use of paintwork on the body. The car owner’s task in this case is to maintain the integrity of the paintwork. Do not allow small chips or scratches to appear on its surface. This method also includes periodic washing of the car, as well as the use of additional protective agents - wax, liquid glass, and so on.

   An active method of combating car corrosion means the use of special anti-corrosion materials and mastics. They differ depending on what areas of the body they are used for. For example, the underbody of a car is often treated with an anti-gravel coating. As a rule, these compositions are based on fine aluminum powder. There are also special anti-corrosion agents for wheel arches. Most often, the so-called liquid locker (strong elastic material) is used for this. A separate class are anti-corrosion materials for hidden cavities. They are designed for processing thresholds, pillars, side members, floor reinforcements and other surfaces.

   The electrochemical method of combating metal corrosion on a car body involves using a special electronic device that contains an electrode designed to take on the corrosion. Simply put, it is not the machine body that will rust, but the mentioned electrode. This method is very effective, but its significant disadvantage is its high price.

   How to remove corrosion from a car

   Now let's move directly to the methods and means of combating corrosion on a car with our own hands. First of all, it is necessary to mechanically remove rust from the surface. And do it very carefully! For these purposes, sandpaper, various abrasive wheels on a drill or grinder, as well as sandblasting are used. It is the latter tool that most effectively cleans the affected surface.

   Special compounds are also used to remove corrosion. The simplest thing in this case is to use a weak solution of hydrochloric acid and then remove it.

   However, the most reliable method of controlling corrosion is to use rust converters or rust modifiers. They convert iron oxide to iron tannate. As a rule, they contain polymers that act as a primer.

   Car rust converters convert corrosion into a layer of iron and zinc phosphates and chromates. They are also sometimes used to treat uncorroded metal before applying primer to prevent future corrosion and improve the degree of adhesion of the paintwork to the metal surface.

   Independent fight against car corrosion has the following sequence:

   Degreasing the surface. To do this, you can use various means, for example, alcohol or white spirit.

   Removing rust from the body

   Remember that all work must be carried out carefully, since even a small rust stain can grow significantly over time.

   The rusty seam is visible

   Always check the condition of the welds on the machine body. Remember that they are the most vulnerable to corrosion. In particular, its intercrystalline type, which is especially dangerous. The consequence of its appearance is an imperceptible loss of ductility and strength of the metal. Thus, the boundaries of welded grains are destroyed chaotically, and the areas of structural transformations turn into an anode, which intensively dissolves. Moreover, this phenomenon can be observed not only on iron car bodies, but also on stainless steel, aluminum, chromium-nickel and chromium alloys. Corrosion in this case threatens to chip away individual grains of metal, which is why the seam and the body as a whole gradually lose their mechanical properties.

   The most rust-prone areas of the car body are the lower parts of the door panels, sills, front fenders, box sections of the lower body, and the inner surface of the wheel arches. Due to the fact that access to the listed places is difficult, there is always a risk of not noticing the appearance of rust spots. Check their condition in the inspection pit or on a lift!

   Popular rust removers

   Currently, there are dozens of different rust converters in auto stores, and their range may vary in different regions of the country. Therefore, it makes no sense to give recommendations regarding the purchase of this or that product. But we will still give as an example several names of popular compounds that are common among car owners. So:

   Popular remedy "Tsinkar"

   • "Tsinkar";
   • "Movil";
   • Hi-Gear line of rust converters;
   • "Chain mail";
   • Sonax;
   • "SF-1";
   • Runway;
   • Permatex;
   • Bitumast;
   • "Phosphomet".

   It must be remembered that with the help of any converter you can fight rust, the layer of which does not exceed 0.1 mm. In addition, the active components only fight stubborn rust. It is better to remove its loose component mechanically (using sandpaper, a knife, a metal brush, sandblasting, and so on).

   The choice of one product or another should be based on the range, its composition, and price. Fortunately, they are inexpensive, so if the purchased product turns out to be ineffective, you can always buy another one.

   Anti-corrosion

   Corrosion is the process of destruction of a metal during its physical, chemical or chemical interaction with the environment. It is divided into three types: – chemical (without the occurrence of electric current); – electrochemical (accompanied by a corrosion current); – mechanochemical (corrosion-mechanical wear, added friction, cyclic bending loads, vibration, etc.).

   The car is mainly characterized by electrochemical corrosion. It is especially intense at relative air humidity of more than 60% and in a polluted urban atmosphere. Corrosion is caused by:

   – weather conditions (rain, snowfall, temperature changes);

   – pollution from acids and alkalis contained in the air, or salt sprinkled on roads in winter;

   – the appearance in the metal after stamping and welding of areas with a changed structure;

   – surface heterogeneity, as well as micro-inclusions of slag and small defects (shells).

   According to the nature of its spread, corrosion can be continuous or local:

   – a continuous one appears on the entire body, starting from the lower surface of the bottom, from the inside of the wings, and in the internal cavities of the doors and power elements (thresholds, cross members, amplifiers). Inside the cabin, it usually occurs under the floor mats;

   – local occurs in places where metal sheets are joined by welding and rolling (edges of the hood and trunk lid, door perimeter). It is more dangerous than solid, as it flows faster, leads to through damage to parts and, as a consequence, to a loss of strength and rigidity of the body.

   Galvanized body parts, although more slowly, also rust, especially in industrial cities. In hidden cavities, corrosion is invisible and therefore most dangerous. When the car moves on uneven surfaces, micro-movements occur in the weld seams of the body elements, reducing the tightness of the parts and destroying the previously applied protective film. Once rust appears on external surfaces, the process is irreversible.

   The underbody of the car corrodes when the factory plastisol coating ages, peels off, and when moisture gets into the formed cavities. In addition, the protective layer is damaged by sand, small pebbles and gravel flying from under the wheels; it is torn off by accidental contact with hard objects - for example, icy snow accumulations in uncleared yards, protruding roots and fallen branches on forest roads, in ruts or when parking on sidewalk curbs.

   The external paintwork of the body suffers from the effects of salt, acid precipitation, dirt and dust, ultraviolet radiation, and temperature changes (daily and during washing). The paint fades, oxidizes, becomes covered with scratches and cracks. As a result, the car begins to rust not only in hidden cavities, but also on the outside.

   When to treat

   At car factories, bodies are primed and painted, mastic (plastisol coating) is usually applied to the bottom, and protective compounds are applied to hidden cavities. Some body parts are galvanized. Sometimes manufacturers guarantee the time until through-body damage occurs. Nevertheless, it is periodically necessary to do additional anti-corrosion treatment. It all depends on the car:

   – new foreign cars rarely require additional anti-corrosion protection after purchase. During operation, individual weak points are identified - you can consult both the car dealership and the anti-corrosion center about the advisability of their treatment;

   – it is better to process new domestic cars completely and immediately. Factory anti-noise plastisols covering the bottom and wheel arches do not penetrate welds, do not contain corrosion inhibitors and only protect the metal from mechanical stress. In addition, the composition is applied before painting, having previously covered numerous threaded holes and studs with technological stickers. When assembling the car, they are removed, simultaneously exposing sections of the bottom. When transporting painted bodies and installing them on a conveyor, local damage to the coating is also possible. If the hidden cavities of the body are processed at the factory, a passport with a protection scheme and warranty conditions for it is usually attached to the operating manual. In this case, it is useful to contact an anti-corrosion center and check the completeness of application and the condition of the coating;

   - used cars. It is recommended to periodically (every year or two) carry out complete anti-corrosion treatment. However, some anti-corrosion centers retain their guarantee if the owner of the car changes. Therefore, if the previous owner handed over the relevant documents, you can rely on their recommendations.

   The frequency and volume of treatment depend on the operating conditions of the vehicle, the completeness of the previous anti-corrosion protection, the preparations used and the warranty conditions of the company that performed the work. In any case, it is recommended once a year, preferably at the end of summer, to visit an anti-corrosion center for a routine inspection and repair of minor damage to protective coatings. In addition, in the spring it is useful to thoroughly wash the car to completely remove any remaining de-icing compounds. Otherwise, in summer, at elevated temperatures and periodic wetting (rain, dew), the corrosion process is activated. At the same time, it is possible to notice and eliminate any defects in anti-corrosion protection. When replacing or repairing body parts after an accident, it is also necessary to restore anti-corrosion protection.

   Conventionally, three generations of compositions are distinguished.

   First: conservation, made from thickened oils with additives of corrosion inhibitors. These materials do not last long on vertical surfaces (doors, thresholds). They flow down, leaving a film that is unstable to mechanical stress and permeable to water vapor.

   Second: film-forming inhibited petroleum compounds (PINS), which adhere well to the metal being protected. The waxy film mechanically insulates it from the atmosphere, and inhibitors block corrosion. Sometimes rust modifiers are contained; they restore the metal, turning corrosion products into an additional protective film about 100 microns thick, similar to soil. Often, an aluminum filler is introduced into the base of the compositions (the word “bronze” or gold is added to the names), it increases abrasion resistance and makes it difficult for aggressive ions (for example, chlorine) to penetrate. Recently, preparations with zinc filler have appeared; its particles, increasing the abrasive resistance of the coating, help slow down electrochemical corrosion.

   Third: materials that contain water or highly purified oils instead of volatile petroleum solvents. Such compositions do not poison the atmosphere. Large manufacturers of anticorrosion agents produce a full range of compounds that differ in the degree of protection. All modern preparations are compatible with factory coatings, and anticorrosives of the same brand are compatible with each other. But it is not recommended to change the brand of the composition unless absolutely necessary. Even specialists at anticorrosion centers cannot always determine how the car was protected. Therefore, it is often necessary to remove the old additional coating from the bottom. And it is almost impossible to remove it from hidden cavities. Sometimes you can find out what a car has been treated with by looking at the sticker on the rear window.

   Materials for protecting hidden cavities (ML-preparations) must:

   – penetrates well into microgaps and cracks;

   – be homogeneous and preferably thixotropic (the ability to adhere to vertical surfaces and set quickly);

   – displace water and electrolytes from the metal surface;

   – effectively impregnate corrosion products (rust);

   – form an elastic film;

   – do not have a harmful effect on the paintwork;

   – have reliable adhesion (adhesion to metal).

   Materials for protecting the underbody and wheel arches (UB-preparations) must:

   – have high adhesion of the protective film to metal and factory coatings;

   – have mechanical strength and abrasive resistance to impacts of sand and gravel, not crack or peel;

   – be elastic and withstand operating temperatures and mechanical deformations of the body;

   – it is good to isolate the metal from aggressive electrolytes.

   Anti-gravel protection materials must protect the factory paintwork from the intense abrasive effects of sand and gravel. This is another processing step. Anti-gravel agents often contain polymer components to increase durability.

   Paint protection materials penetrate into the pores of the paint and provide additional protection. They must be water-repellent, UV-resistant and contain corrosion inhibitors.

   The main stages of complete anti-corrosion treatment:

   – washing the car from below with hot (60–80°C) water under pressure up to 60 atm with the fender liners removed;

   However, modern anti-corrosion materials displace water, so they can be applied to a damp surface;

   – inspection and troubleshooting (some anti-corrosion drugs glow blue under ultraviolet irradiation);

   There are two ways to access the “labyrinths” for processing: with and without drilling additional holes. As a rule, the first method is used. The second is much less common, because almost all cars have inaccessible volumes that require special equipment to process; – after application, the preparations gradually (about a day) set. During this period, it is better to refrain from operating the car. When forced to travel through snow, water, dirt and gravel roads, you must move carefully. In addition, you can drive a car with a catalyst no earlier than three hours after treatment. The car cannot be washed for a week.

   As a rule, an anticorrosion center is chosen based on the recommendations of friends or based on one’s own experience. The last method is the most correct, because the quality of the work is confirmed by time. In addition, a good company has indirect distinctive features:

   – positive reputation, work experience and official representative status (direct supplies of anti-corrosion compounds);

   – the opportunity to familiarize yourself with the list of work performed and technological maps (schemes) for processing vehicles;

   – certificates of specialist training and company certification;

   – a complete set of equipment for all types of processing (main types of nozzles for spraying drugs);

   – cleaning and washing the car immediately after treatment or, if provided for by the technology, after a certain period of time;

   – competent staff answers to questions about the purpose of the materials used and their differences, the essence of processing, etc.;

   – a guarantee for the safety of the body and its preventive maintenance, the conditions of which are detailed in the relevant document.

   Do-it-yourself anti-corrosion treatment

   Let's say right away that it is better not to do this: self-treatment is less effective than that done in an anti-corrosion center, where special equipment and well-established technology are used. But if you still decide to do the processing yourself, then it is useful to consider that:

   – it is not recommended to reduce the amount of preparatory and main work by skipping individual stages;

   – it is advisable to reproduce as much as possible the conditions and processing modes adopted in anticorrosive centers;

   – the benefits of “folk” remedies (mining, gun fat, bitumen, shale mastics) are small - they do not contain inhibitors, create a greenhouse effect and can peel off the factory plastisol coating;

   – modern preparations sold in aerosol packaging are intended only for minor repairs of the corresponding anti-corrosion coating. They have a low concentration of protective material - no more than 30%. The remaining volume is occupied by solvent and propellant;

   – it is advisable to use formulations identical to those used in anti-corrosion centers, but packaged in small-volume containers (so-called Euro-cylinders with a capacity of 1 liter).

   When purchasing drugs in a store, you need to pay attention to the accompanying information. It should contain:

   – information about the manufacturer (company name, address, contact numbers, etc.);

   – characteristics of the drug: name, purpose, color, consistency, type of solvent;

   – standard or specification number, date of manufacture, shelf life, batch number;

   – technological application features: type of surfaces to be treated and their preparation, effect on paint and varnish coatings, method of application and removal, temperature ranges of treatment, drying modes, thickness of dry and/or wet film, number of layers, drying and holding time before use, consumption;

   – precautions for storage and use, urgent measures in emergency situations.