Do-it-yourself anti-corrosion treatment of the body

Anticorrosive treatment of the underbody and hidden cavities of the body

Publication date: April 19, 2016.
Category: Automotive equipment.

The supporting element of each car is, of course, the body and its bottom, which serves as the so-called platform on which the main elements of the car are located. That is why, when purchasing a used car, the buyer first of all pays attention to the bottom, since if it is in a deplorable condition, then there is no point in spending effort on repairing it.

Thanks to modern technologies and the latest developments, today cars come off the assembly line with reinforced bodies, which are covered with special materials, such as fiberglass or polymers. Unfortunately, such treatment cannot yet be found on all cars, especially for domestic models, the body of which is made of ordinary metal, which is susceptible to the harmful effects of corrosion. But, even if you own a foreign car, this does not mean that at some point you will not find yourself with a “bare bottom”. The fact is that some manufacturers, in an effort to reduce the cost of a car, prefer not to spend money on additional processing; as a result, consumers get a “pig in a poke.”

Corrosion progresses quickly and can affect the most important and expensive elements of the car in a matter of months, which, in turn, will affect the operation of the chassis, suspension and other elements. If you carry out diagnostics and treatment in a specialized car service at least once a year, then there is nothing to worry about, but if you prefer to do everything yourself, then be sure to carefully check all possible places where rust occurs.

Types of metal corrosion

Rust formations can be of different types, and today there are about 20 varieties of such “damage”. Let's look at the main types of corrosion:

Gas - destroys the muffler, exhaust pipe, as well as the chamfers of the exhaust valve plates located in the combustion chamber.
In non-electrolytes. Most often, fuel and oil systems are subject to such corrosion.
In electrolytes. Rust forms as a result of stagnant moisture.
Under tension. Most often, this corrosion appears in areas subject to high stress.
Contact - formed in places where metals of different potentials come into contact.
Slit. This type of corrosion occurs as a result of stagnation and contact of moisture with oxygen in narrow gaps, crevices and cracks in the paintwork.
Atmospheric - appears during improper transportation, operation or storage of the vehicle.
Biocorrosion is rust that appears under the influence of microorganisms and their metabolic products.
Structural. Formed after welding.
Mechanical. This type of corrosion is the most common, as it is caused by impacts from pebbles or crushed stone.

Corrosion can also form if you often drive through tall grass or sand, or leave your car outdoors in winter or, conversely, in an unventilated garage.

Requirements for materials for anti-corrosion treatment

Based on the fact that there are a huge number of types of rust, strict requirements are imposed on anti-corrosion compounds, for example:

the anticorrosive agent must be environmentally friendly, that is, it must not pose a threat to both the environment and humans;
the compositions must have good frost resistance, so that all protective properties will be maintained at low temperatures;
the anticorrosive agent must be plastic so that the composition does not deform during vibration;
have high activity (this applies to cars that have already been affected by corrosion);
The anti-corrosion material must be resistant to abrasives.

Most coatings meet these requirements, but in order to choose the best one and make anti-corrosion on the underbody of the car with your own hands, it would not be superfluous to consider the main types of anti-corrosion compounds.

Types of anticorrosives

Today, there are several categories of anti-corrosion agents that are used for external or internal surface treatment.

Bitumen (mastics)

Such compositions form a bitumen film on surfaces, which provides waterproofing of exposed parts of the body. Among such means, several compositions can be distinguished:

Slate mastics. Used to protect the underbody and outer sides of wheel arches.
Multi-bitumen mastics. They also form a protective layer on the surface, but in addition to this, they also protect the bottom from mechanical damage. In addition, multi-bitumen mastics are resistant to severe frosts (withstand -60 degrees).
Bitumen-rubber mastics. They are used for both external and internal processing. Compositions of this type are characterized by increased elasticity.

If we talk about manufacturers of bitumen materials for body protection, then it is worth highlighting the following brands.

"Tektil anticorrosive" is a product of the Dutch company Valvoline. The compositions of this manufacturer are divided into several types: first, second and third generation. The former slow down the formation of corrosion. The second group includes liquids that contain metallized fillers that increase the abrasion resistance of the protective film. The third generation of TECTYL compositions are the latest anticorrosion agents developed on the basis of finely dispersed colloidal solutions with zinc particles.

The composition is produced in Sweden. "Dinitrol anticorrosive" is presented in two types: CAR - for external surfaces and ML - for protecting internal elements. Anticorrosives of the latter type are soft and have good fluidity, due to which they fill microcracks, preventing the formation of corrosion. The main advantage of anticorrosion agents from this manufacturer is the minimum solvent content.

Another Swedish manufacturer that produces high-quality bitumen compounds. For treatment, products called “Mercasol anticorrosive” are successfully used. At the same time, the compositions of the ML series are used to protect internal surfaces, and AL was developed specifically for the bottom. In addition, MERCASOL offers highly resistant protective varnishes and sprays.

"Anticor Body" is made on the basis of bitumen, rubber and synthetic resins. The highly elastic composition of this brand reliably protects the underbody of the car from mechanical damage that can occur when gravel, crushed stone, etc. fly from under the wheels. Anticor Prim Body is very popular among car owners due to its characteristics, long service life and low price.

Paraffin-based compounds perform well as long as they are in a liquid state. But as soon as the product begins to evaporate from the surface, its anti-corrosion properties also disappear, which is why such anti-corrosion agents are considered less durable than their bitumen counterparts. Another disadvantage is poor adhesion and mechanical strength.

However, wax anti-corrosion protection has its advantages. For example, anticorrosive agent can be applied to both painted and “bare” metal surfaces.

If we talk about manufacturers, car enthusiasts identify the following brands of wax compositions:

Product of a Belgian company. In addition to wax, this composition contains a number of mixed-bitumen components, which gives this product greater strength. The coating does not freeze at low temperatures and does not change its properties in hot weather.

Swiss anticorrosive agent is used externally. The composition is highly resistant to temperature changes and has good ductility.

If we talk about mastics, their advantage is that these compounds penetrate into the surface itself, remaining in it for a long time and preventing the formation of corrosion. However, the products do not reliably protect against mechanical damage and the formation of new cracks. Wax products cover the surface with a film, but do not penetrate inside, as a result it turns out that if rust has already appeared in some area, it will continue to develop.

In order to combine all the advantages and eliminate the disadvantages of these two compounds, “Rust Stop Anticorrosive” was born from the Canadian company RUST STOP. This composition penetrates the surface at the molecular level, making it possible to displace more than 95% of moisture. As a result, a reliable insulating layer consisting of hydrocarbons is formed on the surfaces. Compared to analogues, “Rust Stop” never hardens.

In addition to bitumen, wax and the latest anticorrosion agents, there are also Movil, anti-gravel and other compounds.

How to properly treat with anticorrosive

To independently treat the underbody of your car with a protective coating, you will need:

degreaser (you can use regular acetone or white spirit);
tools for scraping off dirt and already formed corrosion (screwdrivers and wire brushes);
sandpaper;
sprayer or brush for applying a protective composition;
a mirror so that you have the opportunity to examine all parts of the bottom.

Next, you will need to prepare a homemade composition, which may consist of the following materials:

soundproofing material (for example, Body 950), of which 400 milliliters will be enough;
any means to protect the bottom from mechanical damage;
vibration-absorbing mass with anti-corrosion properties (for example, “Cordon”);
directly the anticorrosive agent itself, of the brand you have chosen;
ordinary plasticine;
brown cannon lard;
sealant or any other similar that can be used to fill gaps and cracks.

Once you have prepared everything necessary for processing, you need to perform the following steps:

Remove insulation and old soundproofing materials.
Remove the wheels.
If you are treating interior areas, place protective covers on the seats and dashboard.
Wash the car thoroughly and wait until it is completely dry (you can use warm compressed air to speed up the process). For washing, a regular soap solution supplied under pressure is suitable.
Sand the surfaces with sandpaper or a rubber sanding block to remove corrosion.
Degrease the under-wheel area and treat it with sound-proofing material.
Mix cannon fat, plasticine and vibration-absorbing composition. Heat this mixture in a water bath and wait until it turns black, after which the liquid can be removed from the heat.
Apply the resulting composition with a brush to the underside of the car in a thick layer.
Treat the screws of the removed parts with anti-corrosion agent, then wait 3-4 hours and install them in place.

In order for everything to be done correctly, it is recommended to treat surfaces in the following order:

wheel arches;
fasteners and bolt connections;
suspension;
inner part of the hood;
ball joints;
welds.

After treatment, do not use the car for 24 hours.

In custody

You can carry out the treatment with a protective composition yourself, the main thing is to rinse the surface well and clean it of any contaminants. However, you can also contact a specialized auto center, for example, Amt Anticorrosive, Primula Anticorrosive, or any other organization whose name includes the word “anticorrosive.”

Do-it-yourself anti-corrosion treatment of the body, secrets and tricks (photos and videos).

Good afternoon. The topic of today’s article is do-it-yourself anti-corrosion treatment of the body; in the article you will find recommendations for anti-corrosion treatment of hidden cavities and preserving the paintwork for as long as possible to prevent external corrosion.

Anti-corrosion treatment of hidden body cavities.

The rotting of an undamaged car always begins with hidden cavities in the body. They are filled with dust and dirt, all this is wetted with water and a favorable environment for corrosion is obtained.

Therefore, before choosing an anti-corrosion compound, it is necessary to rinse and dry the hidden cavities. This is done like this:

After this, you have a fork of 3 options with approximately the same efficiency, but different labor costs:

Flush cavities with drainage at every oil change.

The option is quite excellent, and if you do it yourself, it’s free! And the option is quite labor-intensive since you will have to open the lids and add oil 2-4 times a year! It's a lot! But with regular treatment, the car will not rust, since the oil film on the metal blocks the access of water and air to it, and accordingly, even the corrosion that has begun is slowed down.

Among the disadvantages, used oil contains harmful substances, and when they evaporate, they can have a negative impact on the health of the driver and passengers. But during the Soviet era, many cars were spilled and nothing bad happened... An excellent alternative to mining is Crude OIL. Yes, it contains a lot of sulfur and impurities, but it is almost impossible to wash it off.

Cheap domestic products such as "Movil"

Movil is a mixture of lithol, motor oil, drying oil, kerosene and corrosion inhibitors. The principle of operation is exactly the same as that of working off - to limit the access of water and air to the metal of the body. Unlike mining, it is more expensive, but it needs to be updated less often - once a year will be enough.

But it is important to understand that, fundamentally, Movil is no different from processing, it dries in the same way, contains harmful substances, and if you skip repeating the treatment, it cracks and stops working.

Expensive imported anti-corrosion compounds.

Friends - all anti-corrosion agents work the same way - they limit the metal of the body from exposure to moisture and air. The fact that manufacturers claim that their product contains zinc or copper or that it restores rust is a vile lie…. Then no one would have overcooked the thresholds or welded holes, everyone would have applied anti-corrosion compounds and restored the damaged metal. Fundamentally expensive anti-corrosion agents differ from cheap ones only in that they need to be updated less frequently, but given their higher price and, remembering that on average a car is kept for 3 years, additional treatment with expensive anti-corrosion compounds makes no sense.

Ineffective methods for protecting hidden cavities from corrosion.

There are often videos on the Internet where car enthusiasts drown cannon fat and blow it into hidden cavities. Colleagues, I warn you against doing this, since it spreads quite poorly and in the end, it will not rot under the pushsal, but nearby, where it did not get, corrosion will do its rusty work... But pushsalo is an excellent anticorrosive agent for the bottom, on top of the mastic.

Independent anti-corrosion treatment of thresholds.

We have a separate article on the anti-corrosion treatment of thresholds on our website, so there is no point in repeating ourselves, but briefly:

The threshold is hollow inside (covered cavity), so we wash it and apply an anti-corrosion compound. On the outside, the threshold is sandblasted from under the wheels of a car and, accordingly, if the coating is damaged, it rusts. It is important to periodically restore the paintwork of the thresholds, and we also have articles about this on our website (how to paint the thresholds with anti-gravel and how to paint the thresholds yourself)

Anti-corrosion treatment of the bottom.

From the factory, on modern cars, the bottom is covered with primer, and a polyurethane sealant is applied to it and sometimes painted; the same sealant is applied to the wheel arches. In general, this coating serves reliably and perfectly protects the body from rust until it cracks or gets chipped with stones.

In “collective farm repairs”, in most cases, bitumen mastic is used. There is nothing wrong with this, it protects the bottom from corrosion quite well, but until it cracks, and it cracks in the first winter in cold weather, when the body plays on uneven surfaces and the mastic ceases to be plastic. Therefore, if you apply bitumen mastic and hope that it will protect the body from corrosion during year-round use, you are mistaken!

The best version of bitumen mastic is rubber bitumen mastic. Unlike bitumen, this mastic remains plastic at temperatures down to minus 10-30 degrees, depending on the composition and manufacturer, so if your factory sealant is damaged, it is optimal to cover the damaged areas, first with epoxy primer, and then with rubber-bitumen mastic.

If your factory sealant is intact and you want to improve the anti-corrosion treatment of the bottom, an excellent option for DIY treatment is cannon lard.

The procedure for applying it with your own hands is simple - drown the pushsalo on the tile until it becomes liquid and apply it with a brush.

If you apply a push-salo to bitumen mastic, you will be disappointed - the push-salo can lift it! But if you apply pushsalo over polyurethane sealant or paint or primer, you will provide excellent anti-corrosion treatment.

Preservation of paintwork.

Over time, the body inevitably becomes damaged. Due to chips and deep scratches, paint damage to the metal is possible. In this case, 2 options are possible.

Rust comes out and in general, it is ugly, but not fatal. If you touch up such a chip with a brush, or a special one. with a marker, there is a high probability that the rust will stop.

Everything is much worse if a bug inflates next to the chip:

The beetle must be removed as quickly as possible, since under the raised paint a cavity forms and water gets into it and does its job. We already have an article on our website about how to remove beetles, and we won’t repeat it. They must be opened, stripped down to metal, primed and tinted.

Conclusion.

The lifespan of a car is largely determined by the safety of its body; accordingly, if you keep the car body for as long as possible, you will be able to sell the car as quickly and as expensively as possible.

That’s all for me today, if you still have questions about how to do anti-corrosion treatment of the body yourself, or if you want to add to the article, write comments.

TOP products for anti-corrosion treatment of car bodies

The durable metal surface of new or old cars is coated with special anti-corrosion agents. This allows, under conditions of constant use, to extend the service life of the car body for a long time.

The production volumes of anti-corrosion coatings continue to grow because all means cannot protect even the highest quality car from the oxidative effects of air, water and time. With a skillful approach and regular care of the condition of the car, when applying an anti-corrosion coating to the car, careful car owners can manage to keep the car untouched by rust for a significant period of time.

The most vulnerable places

Corrosion is the process of destruction of metals. Oxidation occurs due to electrochemical, physicochemical and/or chemical interaction with other substances in the external environment - oxygen and water. The most vulnerable areas of a car to rust are those that are under constant and long-term exposure to external factors.

The open surfaces of the car are subject to mechanical stress and are constantly in contact with atmospheric air containing oxygen. Hard-to-reach areas of the car body cannot always dry quickly after moisture enters, and therefore are also subject to the destructive effects of oxidizing processes.

The most vulnerable places for corrosion in a car are the following:

There are always microcracks in places where car body parts are welded. They are the initial sources of corrosion, especially in the presence of high levels of humidity. In this case, water turns into ice in winter and, increasing in volume, contributes to the appearance of a crack in the seam and its subsequent increase and cracking.

The underbody of the car, the surfaces of the wheel arches, the exhaust pipe, the muffler, the wheel arches, the sills.

The bottom, lower part of the doors and other parts of the car into which crushed stone and other debris flies from the road are constantly exposed to increased exposure to streams of dirt and sand quickly moving from under the wheels, which enhances the corrosive effect. These places primarily need anti-corrosion treatment.

Engine and exhaust system.

In conditions of constant operation of the car engine and the exhaust system, which is closely connected with it, permanent conditions of elevated temperatures and high humidity are created, so corrosion also occurs in this part of the car.

The car interior and internal cavities remain wet and dirty even after several short trips around the city.

It is worth noting that despite similar processes occurring during vehicle operation, vulnerable areas are treated with different solutions. Since the nature and intensity of pollution is heterogeneous, each detail requires an individual approach.

Hidden and hard-to-reach car cavities are treated with liquid oils, wax-containing and paraffin-containing elastic automotive products. Oily car products fill cracks, displace moisture, periodically moving along the surface as the car moves. Substances with a high content of paraffin and wax contain a solvent that gradually evaporates and an inhibitor remaining on the surface, that is, a corrosion retardant.

External surfaces need to be treated with hardening compounds, and internal, hard-to-reach places - on the contrary, with liquid, non-hardening substances.

How to protect your car from corrosion

Anti-corrosion treatment of a machine requires the use of several substances and technologies. During the complete rust treatment procedure, the following types of protection are used:

Protective anti-corrosion substances that actively interact with the surface of the machine and repel moisture, for example, Movil with a corrosion inhibitor.

Refers to mechanical methods of protection. Substances are also used that, after applying a thick layer to the surface of the car, completely isolate the car from corrosion or external influences of sand and gravel. For example, mastics have good protective properties against mechanical damage and corrosion.

Products that transform the surface of a car that has already begun to rust. They cover up rust on the body.

They combine several substances into a single complex.

The first type of anti-corrosion treatment for a car is done with your own hands to prevent corrosion on the bottom of the car. To provide passive protection to the underbody, it is carefully covered with a special material, thus preventing the lower surface from getting destructive fractions from the outside.

Barrier protection and galvanizing method

Anti-corrosion protection of the car body by galvanizing is carried out at the factory. To protect against corrosion, the machine body is dipped into a special bath of molten zinc, as a result of which a strong ferro-zinc (Fe + Zn) alloy with a layer thickness of 0.8-2 microns is formed on the treated surface. In this case, the distribution of zinc throughout the metal of the body is as follows: in the depth of the anti-corrosion protection there is about 70% of zinc and only closer to the surface the zinc content increases to almost 100%.

After properly galvanizing, the machine is closed to corrosion barrier and electrochemically. The car body is also protected by attaching shields, hood spoilers made of plastic material or leather, as well as lockers, that is, plastic fender liners, linings, covers for the sills and the lower part of the doors.

Body lamination

Lamination is the covering of a car body with a special polyurethane, vinyl, anti-gravel film using special tools. This anti-corrosion film not only acts as a barrier to small fractions (pebbles) falling on the car, from scratches, chips and other minor damage, but also prevents sunlight from spoiling the color saturation of your car. This type of protection of the car body from corrosion does not damage the varnish (paint) and does not enter into a chemical reaction with the paintwork, so it can be easily removed when worn. Properly glued film lasts about five to seven years.

Cathodic protection

The effect of anti-corrosion protection when using cathodic protection devices is compared with galvanizing. The principle of operation is the polarization of the metal during the creation of a galvanic couple: the electrode and the protected surface. During the application of cathodic protection, a negative potential of the desired limit value is produced, which prevents oxidation.

The peculiarity of this method is that it protects the car from corrosion even in hard-to-reach places. Moreover, restoration of car parts already affected by corrosion becomes available. Cathodic anti-corrosion protection is also actively used to protect the trunk of a car from external influences.

How are the external surfaces of the body and muffler treated?

According to the variety of compositions of various means for treating a car body against corrosion with your own hands, you can select the following substances:

Anti-corrosion mastic for cars.

Various tread or protective preparations, which are made on the basis of bitumen, epoxy or synthetic resin, sometimes with the addition of rubber, are applied to almost any part of the body. They have sound insulating properties, dampening resonant vibrations of the body. Mastics are applied mainly in a warm, heated form.

It is used as a protective agent with high permanent elasticity, however, such mastic does not protect against impacts and sudden movements of the machine.

Bitumen mastic or bitumen-rubber.

A preventive agent for treating the car body against corrosion, which contains special inhibitors.

Suitable not only for anti-corrosion treatment of external parts of the car, but also for coating the bottom of the car.

Contains elements of different types of mastic and can withstand air temperatures reduced to -60 C.

Polymer liquid anti-corrosion materials (sometimes phosphate), applied to the surface being treated, consist of substances based on polyvinyl chloride or rubber. This anti-corrosion treatment for cars has good adhesion, that is, excellent and durable adhesion to the surface. Apply on a pre-coated primer.

It is a polymer plastic material that is used to treat the most vulnerable areas for corrosion on a car. These are wheel arches, sills, the edge of the hood; liquid plastics are considered additional protection.

The anti-corrosion agent is designed to protect joints, seams and surfaces of the car body. After application and drying, it forms a waxy protective anti-corrosion layer.

Next you need to figure out how to paint the muffler. Protective body painting will help you in this matter. Such protection against car corrosion prevents rust and aging of the metal material. It is advisable to paint the muffler using heat-resistant paint so that the car can be used in hot and cold weather.

The highest temperature point at which protective paint performs its functions is 400 C. To increase the protective and repellent properties of the coating applied to the muffler, you can also choose paint with the addition of silicone.

Anti-corrosion agents for the muffler and other car parts require drying or heat treatment, that is, measures that increase the tightness and strength of metal parts.

Now you have learned how to protect your car from corrosion. To do this, use special car products and films glued to the body.

Reliable and inexpensive methods of corrosion protection - ZR expertise

Modern factory anticorrosion protection quite effectively protects the body from corrosion. But nothing lasts forever. To keep the iron in good condition, the protection needs to be updated. In addition, proper treatment will help slow down the corrosion process that has already begun for a long time.

Underground workers

In addition to the visible wear of the paintwork on the lower part of the body from constant sandblasting and road reagents, corrosion of the internal cavities is inevitable. Weld seams and rolled joints of door panels and trunk lids are also at particular risk. The problem with such areas is inadequate priming and painting, even in factory conditions.

The corrosion process is noticeably accelerated in hidden cavities. Due to poor ventilation, moisture and dirt accumulate there, mixed with road reagents, forming an electrolyte - a corrosion catalyst. And if its external manifestations are visible on the welded points of the bottom, on welds and in places where panels overlap, then everything is much worse inside.

Before applying protective coatings, the underbody and hidden cavities of an older car are washed and dried. This procedure itself significantly delays the onset of serious corrosion, since it rids the surface of aggressive electrolyte.

To protect the body, two main methods of anti-corrosion treatment are used.

Canadian approach

Canada has a humid, cold climate that favors the appearance and development of corrosion. Therefore, it is Canada that is considered the legislator of the so-called ML method of body protection, although it was invented in Scandinavia.

The method involves pouring ML oils (analogues of the usual Movil and the popular Rast Stop product) into hidden cavities of the entire body through existing factory technological holes and drains. Penetrating compounds well impregnate welds and cover the internal surfaces with a film that reliably insulates from contact with air. The outside of the bottom is covered with the same materials.

The ML method is not demanding on the quality of body preparation and forgives a lot of mistakes when applying the composition. In Canada, for example, they don’t wash the bottom thoroughly, but only knock off large pieces of dirt. The ML oils used have excellent penetrating ability and saturate surfaces and seams well even in such conditions.

They can be applied over any rust - the composition includes inhibitors (chemical reaction retarders) of corrosion. But to achieve maximum effect, it is better to thoroughly rinse the bottom and its hidden cavities.

The disadvantage of ML oils is low mechanical strength. In hidden cavities they last for years, and on open surfaces they wear off quite quickly.

Chemical manufacturers also develop processing schemes for machines of specific models. They indicate factory technological holes and additional ones that are proposed to be drilled in order to fully fill all hidden cavities. In fact, servicemen rarely make holes in the body, if only because the owners are often against it. In most cases, additional holes are not so necessary for full processing. By the way, these diagrams are useful for studying the structure of a particular body, especially when a rare model arrives for processing.

SWEDISH REPLY

The abbreviation ML denotes anti-corrosion compounds for hidden cavities of the car body, as well as the treatment method. Behind these letters are two authors: the Swedish automobile association Motormannen and the ideologist of the direction, Sven Laurin. At the end of the 50s of the last century, one of the specialized companies offered car owners a new service - complete body processing using the ML method. Although this technology was first tested 20 years earlier.

The Swedish ancestry is explained by the difficult local climate, which accelerates the processes of iron corrosion. On a global scale, power engineers faced this problem when the country began to actively build high-voltage masts. Their tubular structures were rotting from the inside at an alarming rate. It was then that Laurin proposed his own method - pour anti-corrosion oils into hidden cavities through existing or drilled holes.

Movil, the Soviet analogue of Swedish ML oils, received a consonant name by accident. This composition was developed much later by scientists in Moscow and Vilnius, the Russian and Lithuanian capitals, and gave the product a name. In those days, it was fashionable to invent funny abbreviations and abbreviations.

old light

The second approach is European, more serious. In addition to treating hidden cavities with ML oils, hard (bitumen) protective compounds are applied to open underbody panels and wheel arches. This method is more demanding on the quality of preparatory work. It is important to thoroughly wash the open bottom panels, otherwise the bitumen compounds will quickly peel off.

The main advantage of bitumen coatings is their high mechanical strength. Various types of them, for example, compositions for liquid fender liners or for underbody panels, can protect the metal from external influences for a long time.

Bituminous coatings can be applied to rust, but with reservations. If the corrosion is superficial, just in case, the affected area is impregnated with ML oil and after that a solid composition is applied. With deeper layer-by-layer rust, impregnation with ML composition may not help. Moreover, the development of corrosion cannot be controlled, because bitumen coatings, unlike ML oils, are opaque. Therefore, in each specific case, the master assesses the degree of rust damage and the possibility of applying a bitumen coating over it.

When treating the bottom with a bitumen composition, the same restrictions apply as with ML oils. If bitumen gets into the outlet, like ML oils, it can be removed with solvents, but you will have to spend much more time and effort.

DANGEROUS SAVINGS

There are a huge number of companies on the market offering their anti-corrosion compounds. All products have comparable quality, but preference should be given to well-known players, for example: Tectyl, Noxudol, Dinitrol, Waxoyl.

Branded chemicals are not the cheapest, but they have been tested many times. This is what specialized services work with, having seen the results of using products from dubious manufacturers. Low-quality products do not protect, but kill the body. For example, left ML oils, instead of deeply impregnating surfaces and seams, creating a protective layer, act in the opposite way. They have very low fluidity, clog drains, and also form a thick membrane film, under which corrosion only accelerates. And cheap bitumen compounds have an extremely short service life. Drying quickly and cracking, they to some extent protect the body from mechanical stress, but not from corrosion.

Election campaign

When using a car year-round in a large city, where roads are actively watered with reagents in winter, the first external signs of internal corrosion appear after about five years or 100,000 km. The most economical way to significantly extend the life of the body is to wash the underbody and its hidden cavities every 50,000–70,000 km. In Moscow, this service costs 2000–3000 rubles.

Ideally, it is worth supplementing the first wash of the bottom with treatment of its hidden cavities. Moreover, at the next visit, for example after 50,000 km, it is no longer necessary to rinse the internal cavities and refill them with ML oil - it “lives” there for a very long time. Such complex processing will save a decent amount. For example, for 8,000–9,000 rubles they will thoroughly wash the bottom, treat hidden cavities and apply ML oils to open panels.

This option is suitable for normal urban use. On open surfaces under such conditions, ML oils can withstand 20,000–30,000 km. And if the bottom is covered with plastic shields, the composition will last much longer. A combined approach is also possible. Unprotected and particularly susceptible to sand blasting areas are covered with a bitumen composition. An owner who wants his car to have a long life can “douse” it with ML oils every year over the old coatings.

Treatment with bituminous materials makes sense when operating in difficult conditions and very large annual mileages. This option is suitable for off-road driving enthusiasts and owners of commercial vehicles, as well as participants in amateur racing. It is suitable for both used and new cars. The bitumen coating on the bottom, if not actively killed, lasts for five to seven years. That is, it is quite enough for the average period of car ownership. After the bitumen coating has worn out, it is partially cleaned off and a fresh layer is applied. A package of services, including washing, treating hidden cavities with ML oils and applying a bitumen coating to the bottom, is estimated at about 15,000 rubles.

The costs of protecting the body are comparable to the costs of car maintenance - complex treatment with ML oils and treatment with bitumen compounds cost the same as the first and second maintenance, respectively. Usually it is enough to spend money on anti-corrosion treatment only once or twice - this investment is recouped when you sell the car.

ONE BLOOD

Bituminous materials for protecting underbody panels and fender liners have a single base, but differ from each other, let’s say, in their additive packages. They are added to increase the mechanical strength of the coating in the zone of active external influence - for example, on wheel arches. To do this, the base base includes a reinforcing filler - crumb rubber. Accordingly, such a composition will be more expensive. This coating can be applied to other parts of the body. Let's say, on thresholds subject to strong sandblasting from wheels.

Manufacturers supply compositions for liquid fender liners in different containers and different consistencies, but with the same characteristics. Thanks to this, services can use the most convenient equipment to work with them. Thick compositions are applied with a brush in several layers, and liquid ones - with a sprayer or euro-gun. More viscous material can be diluted with a solvent to use any available equipment.

We would like to thank Antikor.rf for their help in preparing the material.

DIY anti-corrosion treatment: rust, come on, goodbye!

How long the body remains intact is how long the car can last. You can survive the rest, even engine failure, since repairing it or replacing it with a used, but fully functional power unit most often does not involve the same difficulties and material costs as solving serious body problems.

The body is the base, or, if you like, the foundation on which the engine, transmission units, control mechanisms, and additional equipment are mounted. Just as there is no house without a foundation, there is no car without a foundation - for this reason, anti-corrosion protection of the body cannot be delayed for a long time. Now is the time to fight for the body, because winter conditions are not conducive to carrying out preventive maintenance, but the body rusts especially actively during the winter period of operation.

The battle of road workers with ice for the sake of safe traffic has a downside. Brines accelerate the development of corrosion in places where paint and varnish and galvanic coatings are damaged, and “sandblasting” that flies from under the wheels, destroying the protective coating of the body and opening up a new field of activity for corrosion, provides all possible assistance to rusting.

In the spring, the results of the work done by deicing chemicals and abrasive wear during the winter period of operation become especially noticeable. Looking at them is not pleasant, but it makes it easier to find places that require intervention to stop the destruction of the metal that has begun.

However, not all corrosion is equally dangerous. Red spots where the paint has chipped on the fenders, hood or upper parts of the doors impair the visual perception of the car and spoil its presentation, but are more harmless than rust on the bottom, sills and wheel wells of the body. Due to poor ventilation, the internal cavities of the same thresholds, side members, pillars and doors, into which moisture penetrates and lingers for a long time, are also unfavorable. Corrosion also has favorite places - welds, sharp edges, places of kinks and rolling.

Therefore, you need to start anti-corrosion measures not by walking around the car, but by driving onto an inspection ditch or overpass and finding out what the car looks like from below. The inspection will allow you to determine the volume and complexity of the upcoming work and decide whether it is worth doing it yourself or whether it makes sense not to waste your personal time and contact a professional anticorrosion center.

Turning to specialists seems more correct, but is not always advisable. Firstly, it will require cash costs from 120-150 USD when a small-sized car with initial corrosion is processed, and then increasing depending on the size of the car and the complexity of the work. Another drawback is that anti-corrosion treatment does not take an hour or two, so not every car owner is able to monitor its progress. You will have to rely on the professionalism of those who provide corrosion protection services, but, as experience shows, expectations for the accuracy and skill of service station workers are not always justified.

Again, it is not necessary that the car needs complete anti-corrosion treatment. Often it is only necessary to “patch up” a generally good protective coating in places of minor damage that appeared, for example, due to careless driving over uneven roads. Anti-corrosion service stations are not wasted on such trifles. Finally, most anti-corrosion centers are located in large cities, which are a long way from a considerable number of owners living on the periphery, which, coupled with the time required for processing, makes it impossible to contact specialists.

If the decision is made to correct the corrosion situation on your own, there will be no need to use the necessary medications for this. To renew the anti-corrosion coating on the underbody of the car, bitumen-rubber mastics and preparations in aerosol packaging are used.

What to prefer is decided individually. Mastics are applied to the treated areas with a brush, aerosols are applied by spraying, so aerosols are more convenient to use. In addition, flexible hoses-nozzles can be attached to aerosol preparations for treating internal cavities through technological openings provided in the body.

Mechanical damage to the protective coating in internal cavities is less likely than the appearance of holes in the protection of the outer surfaces of the underbody and wheel arches, but is possible in the event of deformation of elements having such cavities. It is also impossible to exclude the aging of materials that protect against corrosion, due to which microcracks appear in them, reaching the metal. Therefore, it will not be superfluous to update the protection in the internal cavities - this is another argument in favor of aerosols.

True, mastics are cheaper. A jar weighing about 2 kg of bitumen-rubber or polymer-bitumen mastic will cost 90-150 thousand rubles. Aerosols are offered mainly in packages with a capacity of 0.5-0.7 liters, costing in the range of 60-90 thousand. You may need a rust converter. Some are brush applied, some are aerosol. The cost of converters is 40-70 thousand rubles. per bottle 0.5 l. If the volume of work to be done is large, a combined treatment would be optimal: apply mastic to the external surfaces, treat the internal cavities with an aerosol agent.

One should not take seriously the statements of manufacturers of anti-corrosion preparations that it makes no difference for a particular product whether it is applied to a wet or dry, rusty or cleaned, dirty or cleaned surface. The loose layer of unremoved old rust and dirt will contain everything necessary for the corrosion process to continue under the freshly applied coating.

Therefore, treatment should be preceded by removing existing corrosion using a scraper, wire brush, or sandpaper. It will also not be superfluous to degrease the surfaces being treated - the protective composition will stick to them more reliably. It is not possible to prepare internal cavities in the same way - this is where you have to rely on the declared properties of anticorrosion agents.

In addition to areas of rust that are visible to the eye, areas where the old coating still holds, but has peeled off from the base, require attention. Corrosion most likely also develops under the formed bubbles, which is easy to verify by removing the peeled coating with the same scraper.

If everything is done correctly, then the corrosion will subside for at least a year, but since it is impossible to completely defeat the “red plague”, the inspection of the condition of the body will have to be repeated next spring. There is no other way to preserve the body and thus extend the life of the car.

Sergey BOYARSKIKH
Photos by the author and from open sources
ABW.BY

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