Causes, methods of combating white rust and methods of protecting galvanized iron from corrosion.

If you leave a piece of iron in the open air, its fate will be sad and inevitable: sooner or later the metal will begin to rot and turn into dust. To delay the onset of the corrosion process and slow it down, automakers use various tricks - they cover the metal body with a multi-layer “sandwich” of mastics, primers, paints and varnishes.

This method works until the protective layers maintain their integrity. But sooner or later, tree branches, stones, unfavorable weather conditions, and chemicals on the roads penetrate the protection - and red dots appear on the body.

To further protect the car, some car companies coat the entire body (or parts thereof) with zinc. But whether a galvanized car body rots is discussed further in the text of the article.

Galvanized or stainless steel: the difference in price pays off during operation

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Galvanized and stainless steel have common properties of corrosion resistance and resistance to environmental influences, which makes the use of these types of metal popular in construction and industrial purposes.

Galvanized or painted corrugated sheeting: which is better?

Corrugated sheeting can rightfully be called one of the most popular materials in construction.

The technology of its manufacture, as well as strength, durability and ease of use, make it possible to use corrugated sheeting in a variety of areas - from arranging formwork for the foundation to erecting a fence around the site. This material can be used to make both temporary structures and those that are designed to last for many years.

To understand which is better, galvanized or painted corrugated sheeting, it is necessary to take a closer look at all the features of each type of material.

Galvanized or stainless steel: the difference in price pays off during operation

You can place an order by phone. Our specialists will be happy to help you.

Advantages and disadvantages

When choosing a galvanized or painted corrugated sheet, you need to carefully study all the pros and cons of these options.

The advantages of painted corrugated sheets include the lower cost of sheets and components for them.

The main disadvantage of this type of corrugated sheeting is its shorter service life. According to statistics, it lasts five times less than its painted “brother.”

The life of galvanized metal is especially short in urban environments, where its aging is affected by harmful fumes from enterprises and exhaust emissions from a huge number of cars.

Acid rain can almost completely remove the zinc coating from corrugated sheets in 5–6 years.

Applying paint to a galvanized surface provides:

extension of service life;
increasing the reliability and practicality of sheets;
their acquisition of aesthetic appeal.

Thanks to a variety of colors, corrugated sheets acquire the properties of decorative materials. The use of galvanized painted corrugated sheeting allows you to create a unique image of your home and garden area.

Due to the fact that painted corrugated sheeting is more reliable in operation, it is recommended to use it in the most critical areas of construction and finishing: for creating floors, roofing, and facade cladding.

Characteristics, similarities and differences

The manufacturing features of corrugated sheets make it possible to divide this material into two main groups - galvanized and painted.

In order for corrugated metal products to last longer, they are galvanized, that is, coated with zinc. But over time, the zinc layer can become thinner until it completely disappears.

To prevent this from happening, painting is required. The product is subject to GOST standards containing a list of characteristics for which it is suitable.

Manufacturing - GOST 24045-2010 standards. The standard establishes important values and indicators. They are classified according to the scope of application, raw materials, and coating available.

Based on the properties of the material, profiles are divided into two groups:

base – thin rolled sheets coated with zinc (GOST 14918-80);
base – galvanized rolled steel with paint coating (GOST 30246-94). The material, color, thickness are standardized.

For metal grades for blanks - GOST 14918-80. For production the following is prepared:

sheet made by cold deformation, thickness – 0.4–1.2 mm. Compliance with the HP (cold profiling) or PC (color layer application) group;
galvanization. Painting thickness 18–40 microns;
paint and varnish materials for enhanced protection - GOST 30246-94.

One of the most important characteristics is the thickness of the steel . Most often, blanks with a thickness of 0.4 to 0.8 mm are used. On the corrugated sheet there is a designation of letters and numbers that carries basic information:

load-bearing rolled products (H) – metal products of the greatest thickness with the largest ridges. There are shallow grooves on the upper plane. Such designs are suitable for maximum loads;
load-bearing wall (NS) - is in the average range both in terms of loads and cost;
wall (C) - can withstand only small loads. Suitable for fencing, canopies, wall cladding, roofing.

The production of corrugated sheets is based on the method of cold rolling of thin sheet metal. Manufacturing includes several stages:

a roll of galvanized or painted steel is installed on an unwinder, which ensures uniform feeding of the sheet, and the workpiece is inserted into the rolling mill;
set the basic parameters of the automatic control system. These parameters include rolling speed, number of sheets, their length;
start up the equipment;
The finished products are removed from the machine, labeled and packaged.

The manufacturing technology of galvanized and painted corrugated sheets differs only at the final stage, when in one of the options galvanization is supplemented with painting.

The marking of profiled sheets is strictly standardized and includes:

name (trademark);
symbol;
size of sheets and how many of them are in the package;
weight;
batch number;
quality control mark of the manufacturer.

The symbol includes the following indicators:

profile type;
profile trapezoid height, sheet width, rolled metal thickness;
material designation;
coloring layer, if any;
standard.

Packaging of corrugated sheets is carried out according to the drawings of the manufacturer. Its task is to protect products and their protective coating from various damages and from the movement of materials in the packaging bag.

Transportation and storage methods must ensure that the cross-sectional dimensions of the corrugated profile are maintained. The packages are placed on wooden supports and securely fastened, eliminating the possibility of movement.

Some reasons for the lack of durability of galvanized coatings

If we exclude from consideration the poor quality of the process itself (most often, corrosion of galvanizing is characteristic only when galvanizing is not carried out under specialized conditions), then the presence of rusty galvanizing is determined by several factors.

Contact medium

Hot-dip galvanized steel has an adverse effect, in particular, on the soil where the structure is placed. Since there are over 200 different types of soil actually found in nature, the effectiveness of hot-dip galvanizing in soil varies and is difficult to predict.

Distinctive features of galvanization and stainless steel

Stainless steel and galvanization differ in their production method, composition, durability, and these characteristics affect the difference in price, reaching 25–40%. This variation in cost is explained by the improved characteristics of corrosion-resistant stainless steel compared to galvanized metal.

Cink Steel

Galvanized steel is produced by coating a sheet of carbon steel with a thin layer of zinc, which over time (up to two years) forms a durable patina on the surface that is resistant to atmospheric moisture and oxygen.

Galvanization must “stand” so that the products of natural oxidation disappear and the zinc patina layer gains strength. Zinc-coated steel sheets differ in appearance from stainless steel - zinc crystallization patterns reminiscent of “white rust” are visible on their surface.

Galvanized steel has the following performance characteristics:

service life - up to 25 years with a zinc coating layer 60 microns thick;
high ability to withstand mechanical loads by rolling, forging, bending, drawing, stamping;
resistance to pressure loads;
resistance to temperature changes;
low electrical conductivity.

Galvanization is not resistant to acids: with the help of hydrochloric acid it can be distinguished from stainless steel. The zinc coating actively reacts chemically with acid, while stainless metal alloyed with chromium does not react to an acidic environment.

Stainless steel

The high-tech process for the production of stainless austenitic steel is based on alloying the alloy with nickel, manganese, and chromium additives, which create corrosion-resistant films on the surface. The material that comes out of production is ready for use and further processing and has the property of self-healing chromium oxide film.

Stainless steel has better properties compared to galvanized metal:

service life – up to 50 years;
plasticity and ability to deform;
resistance to impact loads;
high corrosion resistance to moderately organic and acidic environments;
ease of processing;
resistance to high and low temperatures;
environmental Safety.

Stainless steel does not form harmful compounds upon contact with food and thermal exposure, which distinguishes it from galvanized metal. Galvanizing can be oxidized by many foods and release poison.

offers high-quality stainless, corrosion-resistant austenitic steel at a competitive price, which is due to the absence of intermediaries between the production company and consumers of stainless steel products. The cost of stainless steel products pays off with twice the service life compared to galvanized steel.

What are the supposed experts wrong about...

The worst thing is that informational “pearls” that have nothing to do with reality, akin to the fruit of a sick imagination, regularly appear not only among bloggers, but also on the pages of highly respected automobile publications. If you compile the contents of articles devoted to the “galvanization” of bodies, then they will all come down to one seditious quote...

“There are 4 ways to galvanize a body. Here they are arranged in order of increasing effectiveness:
Cold galvanizing;
Zinc metal;
Galvanic method of applying zinc;
Hot galvanized."

This listing itself already raises serious doubts about the professionalism, competence and level of knowledge of the authors! We will talk about “hot-dip galvanizing”, the mention of which in an automotive context is complete nonsense, in a separate chapter.

Galvanic galvanizing - reality and fiction

Allegedly, “cold galvanizing”, “zinc metal” and “galvanic method of applying zinc” are nothing more than three types of descriptions of the same process - phosphating followed by application of a zinc-containing protective primer to the surface of the body by electrophoresis.

The real differences in the types of this method concern only the nuances: whether passivation is carried out or not, how phosphating is carried out - chemical or electrochemical, what is the composition of the ingredients in the primary electrolyte solution. Of course, first of all, everything depends on quality and adherence to technological culture. But all this is on the conscience of the car manufacturer. The rest does not have any special differences and does not depend on the suppliers of technologies and chemicals.

The second, persistently circulating misconception concerns certain “types of galvanizing”, of which two are almost universally distinguished:
“full galvanization”, when all body elements inside and outside are coated with zinc;
“partial galvanization”, when only the most susceptible to corrosion and impact-abrasive areas of the body, usually “to the waist,” are coated with zinc.

The fact is that it makes no sense to phosphate and/or cover the car body with zinc-containing primer “to the waist” or “to the roof” - in any case, the ENTIRE body will have to be treated: either completely, or not do it at all. The technology is such that the body in electrophoresis baths must be constantly rocked and turned over, and the electrolyte must be continuously stirred.

Even immersing the body in the bathtub must be in a position close to vertical, from top to bottom and at a certain speed. If you simply “plop” the body into the bath and, in a semi-submerged state, carry it through the electrolyte, then, after removing and drying, its entire surface will be replete with defects, the soil will lie unevenly, and the thickness of the layer will be extremely uneven. Eliminating defects will require a gigantic amount of manual labor with the negative presence of the “human factor”, and because of this, inevitably huge financial losses. The technology of completely processing the body, completely immersing it in the bath, is absolutely free of all these troubles.

So, we have found out that at present, as before , only one method of galvanizing a body is used in the global automotive industry - coating it in an electrophoresis bath with a thin anti-corrosion layer of zinc-containing substances by electrodeposition onto the surface of the body from an electrolyte, where these substances are contained in form of a colloidal solution.

The time has come to debunk the most monstrous myth about “hot-dip galvanization,” which is steadily circulating in the minds of the automotive community.

“Hot-dip galvanizing” is a figment of a sick imagination

The so-called “hot-dip galvanizing” is not used in the passenger car body industry, has never been used before and (God forbid) will never be used in the future! I would like to make a special point - “hot-dip galvanizing” has NEVER been used and IS NOT USED!!! And that's why …

In terms of beauty and delicacy of the design, the body of the Peugeot 2008 I can be compared with the Eiffel Tower)))

Imagine... A beautiful, openwork, light, almost airy, intricate and complex-shaped body, assembled from many fragments of steel with a variety of characteristics, just welded on a conveyor belt by ultra-precise (!) robots, for galvanizing, it is lowered into... “a bath of molten zinc , the temperature of which is from 500°C to 800°C” - which can sometimes be read not only from bloggers, but also on the pages of highly respected automotive publications.

At 500°C, precision heat-treated body panels... will instantly “release”, and super- and hyper-strong steels will immediately turn into “plasticine”! This should be clear to anyone who has ever stuck a nail into a fire and seen what happens to it after that... At 500°C, the openwork body will experience such high thermal overloads and deformations that it will, in the most literal sense, be torn at the seams! Even if it doesn’t tear, it will twist worse than Quasimode from “Notre Dame in Paris,” and there will be no way to straighten this crumpled piece of foil back!

Lower the temperature? Will not work! The melting point of Zinc is 420°C.

First galvanize the metal, stamp it, and then weld it? It won't work either! The most widely used body welding technology is spot welding. The two parts are tightly connected to each other, compressed in the right place by “pincers” with electrodes, to which a short but powerful electric discharge is applied. Local heating occurs to 1000-1200°C, and the steel is welded at this point.

The next point, another point, another... Now imagine that at the site of this local heating to 1000-1200°C (the melting point of steel) zinc appears with its “ridiculous” melting point of 420°C. This will inevitably lead to the formation of slag, cavities, and burning, which only later, after painting and operation, will become a powerful source of corrosion, incl. and intercrystalline, i.e. internal, without external influence.

Thus, not only will we not protect the body with zinc in any way, but, on the contrary, we will create a huge number of sources for hidden and uncontrolled corrosion to occur. After exposure to vibrations, the weld points will begin to crack and burst, and after some time the body will fall apart at the seams.

By the way, modern technologies, especially those of the PSA Peugeot Citroen Group, have successfully solved this problem! Before connecting the surfaces of steel parts coated with a thin layer of zinc for subsequent spot welding, a special preservative flux is applied to their inner sides facing each other, which eliminates the burning out of zinc and promotes its instant dissolution in the center of molten steel without the formation of slag and defects. The flux located around the welding point and not taking part in the reaction now plays the role of glue, which, after rapid polymerization, not only seals the joint of the parts, protecting the welding point from the inside, but also helps to further increase the rigidity of the structure.

But let’s return to “hot-dip galvanized”

Energy ! Calculate - what a monstrous amount of energy needs to be supplied to a “zinc molten bath” with a capacity of more than 150 m3!!! In addition, this entire volume must be constantly kept at a temperature of at least 500°C, constantly adding and melting new zinc granules! What if the car is produced in a circulation of 500,000 cars per year?

That's 41,670 cars per month, 1,389 per day and 58 cars per hour! This means that you need to lower 1 body per minute into a bath of molten zinc (around the clock, without holidays or weekends!)! ... In this case, next to the automobile plant there should be some kind of nuclear or hydroelectric power station of the “caliber” of the Dnieper Hydroelectric Power Station!

Carving ! On any body, no matter how high-tech it is, there will always be many and different threaded holes in it! The thinnest layer of zinc that can be achieved with hot-dip galvanizing is 0.1 mm! Not microns, but one tenth of a millimeter! There is no way to make the layer thinner using this method. If you cut a thread before galvanizing, then after applying a layer of 0.1 mm to its turns, even if it is M16, it will hardly be possible to screw a bolt into this hole, not to mention threads of a smaller diameter. If you cut a thread after galvanizing, then the whole point is lost - after the tap comes out of the hole, there will be “bare metal” on the surface of the threads, open to any corrosion and unprotected by anything.

Ecology ! In this case, I’m not talking about Greta Thunberg, but about real ecology. Zinc, after it has been melted, let alone brought its temperature to 500-800°C, begins to actively oxidize and react with everything “that comes to hand”, the result is a huge amount of harmful slag that cannot be further processed, poisonous gases and evaporation... Where should all this go? Gases into the atmosphere, and slag into the street? With a “rate of fire” of 1 body per minute, in a year huge stinking waste heaps will rise around the plant, poisoning everything around with miasma. “Birds don’t sing here, trees don’t grow here” (C) will become a terrible reality.

Hot-dip galvanizing is used in the manufacture of lamp posts, water pipes, fences, bridge elements and similar products - where high precision is not needed, and the part is a body part. In the automotive industry, this method is extremely rarely (!) used for galvanizing any brackets for trucks, their frames, struts, etc.

Today, the best, only and well-developed “galvanizing” technology is the technology of electrodeposition onto the surface of the metal body before painting it.
Environmental friendliness is almost one hundred percent, because no toxins or harmful emissions occur at all.
Energy consumption is minimal and is required only to maintain the required potential difference on the body and bathtub.
The layer of zinc-containing coating is thin, about 10 microns, so it does not affect even the smallest body threads.
The layer is very durable, since microparticles penetrate the surface of the body panel at the molecular (!) level.
Everything is galvanized, right down to the most delicate nooks and crannies of the body.
To eliminate defects due to inevitable bubbles, the body is turned over while in the bathroom, and the electrolyte is constantly mixed.
Drying a newly galvanized body by electrodeposition occurs in the same way as drying after painting it - with a stream of sterile air under infrared lamps.
A priori, the body cannot experience any heating, and therefore internal temperature deformations and associated stresses.

We will leave for later and at your request a description of new, advanced, albeit exotic technologies that have recently begun to be used in car production (including Peugeot, Citroen and all Stellantis products), but which are the future: gluing, lamination, plasma spraying, etc.

The final inspection of the quality of painting and body assembly on Peugeot and Citroen is carried out by gentle female hands - affectionate, sensitive and very beloved by us)))

Some reasons for the lack of durability of galvanized coatings

Contact medium

What corrodes galvanizing in the soil? The main factors determining the corrosiveness of soil are its moisture, pH level and the presence of chlorides. Additional characteristics must also be taken into account:

Degree of soil aeration;
Range of daily temperature fluctuations;
Electrical resistivity;
Texture on the size of soil particles.

It has been practically established that the protection of galvanized steel against corrosion is more effective on brown sandy soils and does not work so well on gray, clayey soils. This is due to the fact that soil with larger particles removes moisture from the surface faster. Therefore, the galvanized part is exposed to less moisture, which provokes the development of electrochemical corrosion.

The first step to assessing the durability performance of galvanized steel in soil is to classify the soil in the area where galvanized iron structures are used. The rate of corrosion of steel in soil can range from less than 0.2 microns per year in favorable conditions, to 20 microns per year or more in very aggressive soils. Thus, highly corrosive soils will dictate the need for a robust corrosion protection system, such as longer-lasting hot-dip galvanizing, to provide long-term protection.

Because soil changes even over a small area and soil corrosivity can vary greatly, incorrect soil classification often leads to unsatisfactory results.

Impact impacts

After rolling, the adhesion strength of the galvanized layer to the base metal is checked according to GOST R 52246-2004. Galvanic protection can be carried out in two ways - hot galvanizing or applying an iron-zinc coating. In this case, the thickness of galvanization is determined by the class of coating. There are four of them:

Types of car body protection

What is galvanizing really?

Generally speaking, “galvanization”: the term is common, simplified and, if we consider it in its literal meaning, it is far from automotive reality, and therefore incorrect! But this process has a correct, albeit long, but accepted name among professionals - phosphating with passivation and subsequent electrodeposition of zinc-containing soil using the cataphoresis method.

Phosphating is the coating of body metal with a thin layer of zinc phosphate to increase hardness and protect against corrosion.

Passivation (derived from the word “passivity”) is the formation of a thin oxide film on the metal surface that prevents the formation of corrosion. The thickness of the oxide film on the surface of body steel is several nanometers (1 nanometer = 10−9 meters). In fact, passivation is the deliberate destruction of the outer layer of metal under the action of a complex oxidizing agent with the formation of persistent salts and oxides, which make up the protective film.

Zinc phosphate (Zn3(PO4)2) is an anti-corrosion substance, which is a fine white powder, has almost zero toxicity, increases the adhesion of paintwork to the body metal and improves the protective properties of paint and varnish coatings.

The chemical protection mechanism is as follows: under the influence of water penetrating through the paintwork, zinc phosphate enters a dissociation reaction to form a complex acid, which reacts together with the oxide film (obtained through passivation) to iron ions in areas of corrosion of body steel, resulting in the formation of a durable complex inhibitor corrosion.

Passivation and phosphating are carried out by dipping a previously thoroughly cleaned and completely degreased body into a bath with a solution of zinc phosphate in demineralized water with the addition of acids and reaction activators. The passivation and phosphating time usually takes from 3 to 7 minutes.

The color of phosphate coating usually ranges from light gray to dark gray. A greenish tint is added to the gray when body steel contains chrome and nickel.

Electromechanical method of protecting the body from rust

After phosphating, the entire surface of the body in a cataphoresis bath is covered with a layer of protective zinc-containing primer, consisting of zinc phosphate, polymers and pigment. This layer is the basis for the subsequent application of paint and varnish. Possessing high adhesion, under the influence of electrical potential differences, soil particles penetrate into the surface of the phosphated metal so deeply and densely that any clear boundary between the metal and the soil virtually disappears. This effect must be taken into account when using various thickness gauges to assess the condition of a car’s paintwork.

After passivation and phosphating, this Citroen C3 I body is subjected to cataphoretic coating with zinc-containing primer

Cataphoresis is the process of transfer (electrodeposition, electrophoresis) of a substance from an electrolyte solution under the influence of an electric current, when the primer or paint is the anode (“plus”), and the body or its part is the cathode (“minus”). Cathodic protection is not quite the correct name for this process in the driving community.

A brief historical background on the use of electrophoresis in the automotive industry...
1963 – the first industrial application of anaphoresis primer on small parts;
1967 – the first experimental line of body painting using anaphoresis;
1974 – first application of cataphoretic primer in the USA;
1975 – launch of the Peugeot 604 and Porsche 924 cars, the bodies of which were completely covered with a primer containing zinc phosphate using cataphoresis for the first time in the world.

Combined protection

Advantages of the method of applying primers and paints using cataphoresis:
Full automation of the application process, in which a person participates only as an observer/controller;
Short application time - it takes only 3-5 minutes to process one body;
High quality of coating - all parts of the body, both internal and external, are covered, while the occurrence of coating defects is almost completely eliminated;
High efficiency and efficiency - up to 100% of unused primer or paint remaining in the cataphoresis bath can be reused to cover the next body;
Environmental friendliness and safety - the primer or paint has a water-soluble base and no more than 2% organic solvents, they do not contain lead, chromium, antimony and any other harmful metals and their compounds, there is a complete absence of emission of harmful gases, fumes and slags.

The properties of the protective primer and the cataphoretic method of its application are such that they provide today the best characteristics of anti-corrosion protection of the body from any external influences.

The 604 may have been the first to use galvanization, but the Peugeot 504 was the first to win the glory of being “stainless.” The photo shows the “504” painting area in Sochaux. 1981

Additional benefits of protective cataphoretic primer:
Smoothing and leveling of small irregularities on the surface of the body, which improves its appearance after painting;
Increasing the warranty period for the absence of through body corrosion from 6 to 12 years;
Protection from external impacts from solid objects (stones, gravel, pieces of wood, etc.);
Maintaining the thickness of the primer coating on sharp parts of the body (edges of doors and hood, flanges and rolling);
High penetrating ability and fluidity, due to which the possibility of high-quality processing of body parts of particularly complex shapes is realized;
Protection of bodies made of a wide range of metals and their alloys (steel, aluminum, duralumin, silumin, magnesium and titanium alloys);
Wide ranges of drying parameters in terms of time and temperature.

After applying a protective zinc-containing cataphoresis primer, the body is subjected to combined drying with streams of sterile air under the influence of infrared radiation lamps, after which a layer of paint (painting) primer is applied to its surface, also by cataphoresis. This soil no longer contains zinc phosphate. Its purpose is to become the basis for the future paintwork of the car, to ensure high adhesion of decorative enamels and varnishes.

This is how the “galvanization” of the best cars in terms of corrosion resistance occurs, including Peugeot, Citroen and Porsche, which became pioneers in the field of anti-corrosion protection back in 1975.

Modern technology for processing car bodies of Peugeot, Citroen, DS and Opel

White corrosion and how to deal with it

The corrosion process of galvanized iron ends with the formation of white rust on the galvanized surface. It is a white chalky substance that forms zinc when exposed to hydrogen (from water) and oxygen (from air). As a result of this reaction, zinc hydroxide is obtained.

White rust on galvanized steel is typical for new material. This is due to the fact that such a coating has not yet had the opportunity to form stable oxides, so hydrogen and oxygen bind to pure zinc. White rust often appears on galvanized sheets during storage, as condensation can get into the gap between the individual sheets.

In most cases, white corrosion renders the protective coating useless. Unlike stable zinc oxides, zinc hydroxides do not adhere well to other materials. White rust is also unattractive from a visual point of view.

There are several ways to prevent white rust:

Eliminate exposure to water.
Eliminate condensation by allowing the zinc to form stable oxides.
Use passivating chemicals or oils.

In the first case, it is necessary to improve the circular airflow of the product. Reasonably increasing the coating temperature or decreasing the relative humidity level is also effective.

Galvanizing is also corroded by prolonged exposure of the structure to a warm environment, since this intensifies the formation of condensate and, accordingly, zinc hydroxide. Another method of preventing white rust is to form stable oxides on the surface of the zinc. They will prevent the formation of white rust. To do this, allow the coating to remain in an environment with low humidity for some time. Increasing carbon dioxide in contact with the coating will also accelerate the formation of stable zinc oxides.

List of cars that do not rust

In the history of the global automotive industry, much attention has been paid to the level of rusting of cars of different brands and models. But it is important to understand that even those machines that are traditionally resistant to metal corrosion in one operating region can behave completely differently in another. And here the quality of materials and protective coatings, operating conditions and the manufacturer’s work on additional anti-corrosion protection are of great importance.

We bring to your attention a list of cars, which was compiled on the basis of the opinions of car designers, body shop technicians and even resellers who have their own “types” of optimally reliable brands/models of vehicles.

Oddly enough, the leaders of this rating are foreign cars that behave better in the conditions of the Russian climate and the poor condition of domestic roads than Russian-made cars.

Porsche Cayenne first generation (2002-2010)

The anti-corrosion protection of this legendary crossover is at the highest level and is considered a benchmark in many respects.

The metal in the Cayenne is well treated with anti-corrosion compounds, and if the car has not been in an accident, it will not rust. The paint layer is quite thick, resilient and elastic, does not form cracks, and therefore is resistant to the formation of rust stains. For the same reason, the car is not afraid of minor bumps and abrasions, and a pebble accidentally flying out from under the wheels rarely leads to damage to the paintwork.

Although the Cayenne itself is almost rust-free, experts recommend closely monitoring its condition after “off-road” trips, when there is a high risk of damage to paintwork and anti-corrosion on the bottom and sills. Risk areas are considered to be areas under plastic parts and at panel joints, at wheel arches and in the seam area of the rear doors.

Skoda Octavia

In our budget, this will be a restyling of the first generation Octavia, produced from 2000 to 2011. Like the entire VAG group, Skoda bodies have excellent corrosion resistance. Since 2004, they began to use full double-sided galvanizing, a layer of zinc on the metal from 9 to 15 microns. Thus, when inspecting even a 14-year-old car, there should be no strong areas of corrosion on it.

Second generation Lexus RX (2003–2008)

If even a Toyota that has been driven headlong is distinguished by commendable anti-corrosion resistance, then Lexus is even more so. This is reflected in a qualitatively different level of color and meticulous elaboration of body elements. And it doesn’t matter whether we are talking about purebred “Japanese” or “Canadians” imported by “gray” dealers in times of a cheap dollar.

The most vulnerable part to corrosion is the crossover hood. Not immediately, but the chips begin to rust. When this RX was young, such cases even caused a part to be replaced under warranty. Corroded arches are most likely the result of poor quality repairs after an accident. The original coat of paint does not give up easily.

In the most advanced version there will be only easily removable surface corrosion. Occasionally you can find red spots on the windshield frame and the leading edge of the roof. With proper care, the bottom, suspension elements and fasteners rust very moderately.

Vyacheslav, professional reseller: “A different (compared to budget models) approach to maintenance has the best effect on the condition of crossovers. At least for the first two or three owners. At the same time, Lexus itself resists rust very well. The main thing is to find an accident-free and crime-free RX.”

Mercedes-Benz S-Class (2005 - 2013)

After problems with the W220 and W203 bodies, German premium cars began to be well protected from rust. This Merc has no weak areas of potential corrosion, and the hood, lower part of the doors and fenders wear out much more slowly than its predecessors.

Pre-restyling models also perform well: if rust appears, it is only locally, in a small area, and is easily removed.

Of the minuses: the fragility of chrome elements and the sensitivity to corrosion of the fasteners of the front aluminum body panels. Particular attention should also be paid to soundproofing material and the integrity of the paintwork on the rear wings and underbody.

BMW 1 Series E87 (2004–2013)

The Bavarians did not skimp on anti-corrosion protection for their debut junior model. Moreover, in its design, unlike its older “relatives,” there is not much winged metal. But there is strong galvanized steel and reliable bottom protection with plastic linings. Yes, underneath you can see rust on the brackets and suspension fasteners or find “saffron marks” on the edges of the rear arches, but that’s probably all. You won’t find more crime even on the “units” of the first years of production, if, of course, they were cared for and cherished.

The paint layer is not very thick, but the “unit” is painted with high quality. The sandblasted front part is a sure sign of road use of the car. Cars that rarely travel outside the city do not have such signs. But even if there are chips, the paint does not bloom for a long time and does not begin to peel off in patches in places of significant damage. And without them, alas, there is no way due to the perky nature of the “penny”.

Anton, master of a car service center specializing in BMW repairs: “The youngest of the Bavarians is losing its luster very slowly. Thanks to the good quality of the paint, the body coating successfully resists clouding after washing. Chips and scratches may not last for years, thanks to proper galvanization.”

Audi A6 in C6 body (2004–2011)

Cars from German brands are frequent guests in the ranking, and Audi is no exception. It is reliably protected from corrosion: even if the paintwork is chipped or cracked, rust spreads throughout the body very sparingly and slowly.

If the car is new or undamaged, it cannot have problems with rust. The A6's aluminum body, with its robust frame, powerful subframes and multi-point side members, is completely inert to corrosion. The main thing is to carefully drive the car off-road and not damage the anti-corrosion protection on the bottom, since it has a low seating position.

Rust can appear due to poor-quality body repairs and the use of cheap non-original components. The weak spot is the front fenders and hood, where the paintwork peels off quickly.

Fiat Albea

As in the case of the Symbol, for 200 thousand rubles you can see the best examples, and since the car was produced right up to 2012, for this money you can even buy a car that will be only 10 years old. The main charm of Albea is that, despite its low cost, it is well galvanized. Ask any owner - if there was no accident, he will confirm.

A 2008 car for only 210,000 rubles with two owners and a mileage of around 140,000 km.

Peugeot 307

The restyling of the first generation Peugeot took place in 2005. The car was produced until 2008. The Peugeot brand has many different problems, but there were no complaints about the rust resistance of their bodies. Since 2006, the 307 has been fully single-sided hot-dip galvanized, which involves applying a layer of zinc ranging from 2 to 10 microns thick.

Toyota Camry XV40 (2006–2011)

The paint quality of the Toyota Camry is far from ideal. The paint layer is thin and delicate and can be easily rubbed off. The paint on the door handles peels off over time, and the bumper and front fenders quickly become covered with scuffs and chips. At the same time, the anti-corrosion treatment of the body of the Japanese sedan is the envy of other classmates. If you don’t pay attention to little things like minor corrosion of the subframes, then even slight blistering of the paint on the hood or on the edges of the doors, which is familiar to owners of some older cars, is a rare occurrence here. In contrast to blooming chrome and corroding and, accordingly, souring fasteners under the hood and bottom.

Andrey, master of a service station specializing in the repair of Japanese cars: “The 40th Camry’s anti-corrosion protection is better than that of some premium models. Even banal corrosion on the edges of the arches is rare and may well be the result not of sloppy repairs, but of enormous mileage, sandblasting and a disregard for maintenance.”

Kia Spectra

A very popular car. It was produced in Russia until 2011, so given the average prices for these cars, there is a chance to get a 9-11 year old car in very good condition. The advantage of not being so old is that it has good equipment, good reliability and excellent corrosion resistance.

Some say that they only see rotten Spectras on the streets, others cite as an example their own cars in excellent condition. My personal opinion is that the Spectra is very well protected from corrosion, and rusty and rotten cars belong to those who started them or were in an accident and did not bother with good repairs. Inspections of cars that have not been in serious accidents make us admire the quality. Besides, for 200-250 thousand you won’t have to choose from rottenness

Price 219 thousand rubles, mileage 119 thousand kilometers, only 2 owners, the car is 9 years old, it has been driven in the same village all its life.

Renault Megane

With a budget of 300 thousand, you can take a closer look at the second-generation restyled Renault Megane, produced from 2006 to 2009. The body of these cars is made of “zinc metal” - a sheet of steel with an elastic coating on a zinc base. The solution, of course, is budgetary, but nevertheless not bad. Most of all, such a coating is afraid of mechanical damage, so rust on a Megane is a sign of an accident.

Honda CR-V

Now let's look at a model from a Japanese manufacturer. In general, all Honda cars produced after 2005 are famous for their rust-resistant bodywork. Many copies of those years of production from the Japanese manufacturer still do not even have “saffron milk caps” on the body.

Honda CR-V is processed by galvanizing 2 sides of the body. In this case, the zinc layer ranges from 9 to 15 microns. This type of processing has been used on this model for a long time, since 1998, but the technology has improved in recent years. From 1994 to 1998, the car was not treated at all, so many copies of those times already have through corrosion.

According to experts, the first pockets of corrosion on this car of recent years of production will begin in 10 years. The manufacturer provides a 12-year warranty against corrosion.

Now in the initial configuration the cost of the Honda CR-V is 2,135,000 rubles.

Volvo XC90 first generation (2002–2014)

This is a unique Swedish crossover in every sense, in which there are no aluminum parts - only steel. This is potentially the main corrosion threat to a car, but it is completely eliminated due to proper anti-corrosion protection of the body.

The steel is very durable, covered with a thick layer of factory paintwork and protected from impacts and chips by plastic linings. Small pockets of rust can sometimes appear at the junctions of steel and plastic elements, but they do not “migrate” throughout the body.

The only weak point of the XC90 is the front subframe and side members, where the paintwork can be damaged when driving off-road.

Hyundai Solaris

In sixth place is another representative of the South Korean concern Hyundai. The Hyundai Solaris model can be purchased at an affordable price. In 2022, Russian car dealerships offer to purchase this model at a price of 750,000 rubles.

Not the lowest price, but experts classify Hyundai Solaris as a budget vehicle. Just like its brother Kia Rio, the car body is resistant to rust.

Opel Astra H

The model was produced from 2004 to 2007. Their body underwent partial double-sided galvanization, with a layer of zinc from 9 to 15 microns. Not as good as the Skoda Octavia, but better than the Renault. The thresholds, bottom and bottom of the doors have been treated, but in other places you can see bugs.

Volkswagen Golf

The cost of a Volkswagen Golf in the car market starts from 600 thousand rubles. The model boasts a wide range of trim levels, four types of gasoline engines of varying power and two types of diesel engines.

The Golf transmission in various configurations can be mechanical or robotic with a different number of steps. The chassis of the model can have front-wheel drive or all-wheel drive. The hatchback has a balanced suspension and is characterized by good handling and comfort.

Among the shortcomings, many drivers note a capricious robotic gearbox, poor noise insulation and low corrosion resistance of the body, as well as the Golf’s long warm-up time in winter.

Hyundai Accent

The machine is very popular on the market. The vitality of Accents can be surprising. Good paint and metal allow cars, even after ten years of life, to be in excellent condition with proper care and provided that there has been no accident with subsequent mediocre restoration. I’ve personally seen quite a few Accents with a “five” body.

Manufactured in 2007, one owner, RUB 235,000, mileage 120,000 km. Not to say that the condition of the car is new, but for thirteen years it is more than good. Previous article Family Frenchman Peugeot 307 SW - for 250,000 rubles

Opel Insignia (2008–2017)

Tired of being the butt of ridicule in the last century, in the new millennium Opel began to shed its fame as rapidly rusting cars. Of the older models, the Vectra C was the first to distinguish itself (in a good way), and Insignia successfully continued its path.

Regardless of the body type, this Opel is painted in an exemplary manner, and some parts resist rust better than on other premium classmates. Even on damaged elements, rust begins to bloom no earlier than after a year. The paint layer itself is not thick, but it boasts good elasticity: with light impacts the paint does not fly off the body. The anti-corrosion protection of the underbody is holding up well: a six-year-old Insignia from below can look like a one-year-old car.

Leonid, master of the body department of a multi-brand service station: “Insignia rarely suffers from body diseases. This is no longer the leaky Opel from the jokes. On the same hood, chips do not have to be repaired urgently. There is time to wait before painting the entire part. The only upsetting thing is the corrosion around the door hinges, and not on the body - on the door itself.”

Ford Focus

Let's move on to the "Americans". Ford Focus is one of the few budget models that is fully hot-dip galvanized. The thickness of zinc in a car ranges from 2 to 10 microns. According to experts, the car will not rust for as long as 20 years, which is an excellent indicator for the budget segment.

The cost of the car starts from 980,000 rubles. Manufacturer's warranty – 12 years.

Volvo S80 second generation (2006-2016)

The Swedish sedan also demonstrates miracles of anti-corrosion resistance and has virtually no “weak areas”. The body is made of galvanized steel, high quality assembly and a durable layer of paint reliably protects the metal from rust (it does not spread even if chips appear).

The main and only threat to the car body is poor-quality repairs and non-original components.

Ford Fiesta

The compact Ford Fiesta car is presented on the secondary market in pre-restyling variations from 2008-2012 and restyled versions from 2016-2019. They cost from 300 and 500 thousand rubles, respectively. The car is present on the market in hatchback and sedan bodies and has a wide range of trim levels and a wide variety of engines.

The Fiesta has a high level of security. All crash tests for this vehicle are rated 5/5. It has earned the love of drivers thanks to its practicality, efficiency, handling and maneuverability. Ford Fiesta has some disadvantages, including:

Very cramped interior;
Fragile steering rack and stabilizer struts;
Low ground clearance;
Backlight too harsh.

Mitsubishi Lancer

In tenth place in the ranking is a truly legend of the Japanese automobile industry - Mitsubishi Lancer. It is popular not only in Russia, but also in many countries around the world.

A reliable, pleasant, comfortable car with a corrosion-resistant body, which is fully galvanized during production.

Chevrolet Lacetti

The Chevrolet Lacetti car confidently takes eighth place. Despite its low cost, manufacturers did not skimp on the body. It is completely galvanized.

If the vehicle was not involved in an accident, the owner looked after it with all responsibility, then rust stains will not be found even on the first copies.

Audi A4-A6

The model is characterized by high anti-corrosion properties. Signs of rust are difficult to notice even in the area of chips on the rear wheel arches. The paintwork on the hood and front fenders is the first to wear off, but this process takes place without rusting. And all because these elements are aluminum.

The body is strong, with reliable subframes and side members with numerous point fastenings.

The only negative may be the small ground clearance. The bottom often comes into contact with various kinds of obstacles, due to which the protective layer is erased.

Car service specialists note that replacing failed spare parts with original aluminum parts saves owners from headaches with corrosion. If you use steel parts, then problems with rotting cannot be avoided.

Mercedes S-Class W221 (2005–2013)

Mercedes took into account their mistakes made with the W220 body, which had a level of anti-corrosion protection that was not appropriate for a flagship. Therefore, the quality of painting and processing of the W221 body panels was taken very seriously. Pockets of corrosion in areas of paint chips in traditionally vulnerable areas such as the hood, bottom of doors and fenders are rare.

The area, as a rule, is small and grows very “reluctantly”. This allows even the most “elderly” pre-restyling sedans to look invigorated. Although the chrome finish gets cloudy quickly. Front body panels made of aluminum may have problems with rust near the mounting points. Occasionally, the sound insulation coating on the rear wings and underbody peels off, which can lead to serious damage to the paintwork in places invisible to the eye.

Dmitry, an employee of a studio specializing in detailing: “You rarely see rust on the W221, even on copies imported from America (with not the most transparent history - editor's note). And dealer sedans are all the more in complete order with this. In addition, such cars are still well looked after, problem areas are immediately repainted.”

Second generation Lexus RX (2003–2008)

The body parts and paint quality of the cars of this premium car brand are always at the highest level. Rust is definitely not a problem for expensive “Japanese”

However, the hood of SUVs causes some complaints. Over time, chips and cracks in the paintwork appear, and small pockets of rust are possible. Corrosion can also be caused by poor-quality repairs and the use of non-original components.

Honda Accord

The second place in our rating is occupied by the representative of the Japanese automobile industry, Honda Accord. This is understandable. After all, Japan has always been famous for its high-quality products, no matter what they produce.

Vehicles produced in this country are among the most reliable. But it should be noted that copies released before 2005 were processed worse than their successors. The Honda concern itself guarantees customers that this model will not be subject to corrosion for 12 years from the date of release.

Removing rust from galvanized steel

The procedure begins with cleaning the already noticed areas of corrosion. An effective method is to subsequently coat the galvanized surface with a passivating chemical or oil. In the first case, oxidation is prevented (albeit for a short time), and in the second, a protective barrier is created between the zinc and water, which prevents the formation of a layer of zinc hydroxide. Most of the oils used, however, evaporate after a short period of time, so periodic renewal of this protective coating is required.

Previously, to prevent corrosion of galvanized iron, compositions based on hexavalent chromium compounds were used, but now such substances are recognized as toxic and are used extremely rarely.

How to treat galvanized steel against rust?

Special rust converters are used. In order to remove rust from galvanized steel, first clean the surface, then dry it thoroughly, and then, strictly following the manufacturer's instructions, apply a protective agent. Combining several compounds is undesirable, since they will require different application technologies, as a result of which it is possible to remove rust from galvanized steel.

Rust appears due to violations committed during installation

Galvanized sheets can withstand the harmful effects of rain, snow, temperature and pressure changes. But it also has a limit of strength. This occurs due to errors made during installation or storage. The most common mistakes that lead to early destruction of the metal are an incorrectly designed roof, when water, instead of draining, remains on the surface of the roof or gets under it.

Incorrect laying of sheets

The sheets should be placed one above the other so that the top one covers the bottom one by 5-10 cm and one wave on the side. If the order is disturbed, water will flow between the joints under them and linger there. Prolonged exposure to moisture leads to oxidation of the surface and the appearance of brown spots. Another reason why galvanized roofing rusts is improper fastening of sheets or installation of protective elements. Incorrectly installed ridge, the presence of extra holes in the sheet or its loose fit to the roof sheathing.

Using an angle grinder

This construction device is also called a grinder. Despite the existing opinion that it cannot ruin the coating, experience proves the opposite. If the galvanized sheet has a very thick zinc or polyurethane coating, then the consequences of the negative impact will not be so obvious, but where the coating is thin, rust will appear soon. Not only the cut, but also the side surface of the sheet will begin to oxidize. Rust spots and stripes begin to appear on the back side at the points where sparks from cutting with an angle grinder hit.

However, traces of metal oxidation may also appear on the front side. The grinder disc heats the sheet when cutting. As a result, the protective coating fades, becomes covered with microcracks, and loses its protective properties. When working, it is better to use not an angle grinder, but special scissors for cutting metal. You can also purchase a special attachment for the drill.

Does galvanized steel rust?

Advantages of using painted galvanization

The top coating - paint - increases the properties of galvanization and gives it the following advantages:

Increases service life.
Improves appearance.
Reduces sound conductivity (slightly).

Parameters of metal for painting

For painting, tempered thin sheet steel is used with the following sheet parameters (in mm):

width 710-1800;
thickness 0.5-2.5;
length 2000-2500.

Permissible errors for the workpiece surface

The quality of the surface before painting is controlled by GOST 16523-70. The standard defines the following permissible violations of the integrity of the zinc layer (for the PC group - for painting):

streaks, layers and paths, dark spots from them;
roughness of the coating, grains in the form of a rash, light spots;
pattern with blurry streaks due to zinc crystallization;
scratches, abrasions, marks from bending of the steel strip.

The listed external deformations are permissible if they do not damage the coating. The difference in thickness of the zinc layer for painting can be no more than 12 microns. The finished painted layer must have a smooth surface. Depending on the additives, it can be matte or shiny.

Buy painted galvanized sheets

The price for galvanized sheet metal, with enamel or polymer coating depends on the thickness of the metal, the size of the sheets or the width of the rolls, and the number of processed sides (1 or 2). In the middle region (Moscow region) the price of painted galvanization is (dimensions are given in mm):

0.35x1250x2500 - price 548 rubles/sheet or 230 rubles/m. p., if unwinding from a roll;
0.55x1250x2500 - price 813 rubles/sheet or 324 rubles/m. p., if unwinding from a roll;
0.7x1250x2500 - price 963 rubles/sheet or 396 rubles/m. item on a roll;
0.9x1250x2500 - price 1265 rubles/sheet or 506 rubles/m. item on a roll.

Poor quality fasteners

Galvanized sheets are attached to the roof sheathing using self-tapping screws. The number of screwed elements is on average 7-12 pieces per sheet. All fasteners: washers and screws must have a high-quality galvanized coating of at least 10 microns, and the washers must also have a silicone lining. If the lining is made of rubber, then under the influence of temperature changes it will begin to crack and crumble. The self-tapping screw will begin to rust, followed by galvanized roofing sheets. Any violation of the integrity of the sheet increases the risk of rust. It is almost impossible to check the quality of fasteners by eye - you need to request a quality certificate from the seller.

Storage rules

It is possible to protect the surface of a galvanized sheet from rust. You just need to follow the rules of operation and storage. If storage conditions are violated, the risk of corrosion is even higher than with improper operation or installation.

Store in a dry, well-ventilated area.
Do not place near metal objects that quickly rust. For example, iron mesh, nails, tools without protective coating.
Prevent moisture from entering, including from the ground.

During transportation, galvanized sheets must not be bent or hit against anything. When bent, microcracks form on the surface, which are not visible to the naked eye, but subsequently they can become a source of corrosion. Corrugated sheets or metal tiles that are damaged or have traces of rust should not be used as roofing material.

Low quality galvanized coating

Not all manufacturers produce high quality products. The issue is the price. The better the protective coating, the more expensive the roofing material. In pursuit of a low price, the buyer often forgets that it is more profitable to do the roof once and for a long time than to replace it after two or three years.

Determining by eye whether it complies with GOST and how high quality it is is not an easy task, especially if you do not have much experience working with sheet roofing materials. Even if the corrugated sheet is thick and gives the impression of great strength, this does not mean that it has a thick zinc coating. And the period of its use depends on this. The buyer needs to request a quality certificate from the seller for the product of interest.

The most reliable way to protect yourself from purchasing a low-quality product is to purchase building materials only from a trusted seller. It is desirable that it has been operating in the market for several years, has a large supplier base and specially equipped warehouses. Such a seller will not risk many years of reputation for dubious profits.

When purchasing, you need to focus not only on price, but also on quality. It is necessary to determine what factors make up its cost. This can be the originality of the pattern or the technical characteristics of the material - length, width, thickness (must be at least 0.45 mm), number and height of waves (determine strength and flexibility).

Prevention of corrosive plaque

The car body is not only the most expensive, but also from the point of view of strength of materials (resistance of materials) - the most important part of the car. While driving on a regular road (not to mention off-road and accidents), it has to experience a huge number of various deformations, be subject to vibrations and dampen them, dissipate energy, etc., etc. Therefore, any thinning, hole or weakening of any of its elements is a potential stress raiser and a source of problems. On a rusty, “rotten” body, a hole or a place appears where it will someday break, break, and... it’s good if this happens somewhere “in the open field”, and not in a high-speed accident! Holes and weakening of body elements primarily appear due to the destruction of metal by oxygen, the appearance of rust, and then a through hole...

Electrochemical series of elements (school chemistry course):
Li→Rb→K→Ba→Sr→Ca→Na→Mg→Al→Mn→Cr→Zn→ Fe →Cd→Co→Ni→Sn→Pb→H→Sb→Bi→Cu→Hg→Ag→Pd→ Pt→Au

Let's find Iron (Fe) in it. Now look: metals that are more active than iron are located to the left of it, less active ones are to the right.

If we cover a sheet of iron with zinc (Zn) or zinc-containing substances (hereinafter simply “Zinc”), then this layer will prevent oxygen from penetrating the iron and oxidizing it, making it rusty. If the zinc layer is damaged, then the place of damage with direct contact of iron with air will inevitably begin to be oxidized by oxygen.

If a layer of iron is coated with tin (Sn) or copper (Cu), which are less active than Fe and are located to the right of it, if the layer is damaged, the iron will actively begin to oxidize - the layer of tin or copper will remain intact, but the iron underneath will quickly rust out. "! Therefore, car bodies were never tinned (i.e. covered with tin) or copper plated!

Zinc, as a more active metal, “takes on” the entire “chemical-oxidative load”. If the iron is coated with zinc, then if its layer is damaged, the sheet will rust not in depth, but in width! Thus, the zinc layer prevents the appearance of through holes on the body. Oxidation (rusting) will occur in any case! However, the source of rust will not be directed inside the part, but along its surface.

The essence of “galvanization”: even if the paint coating has “swollen”, the part is intact and there is not even a hint of “rot”. This can be easily restored!

Example No. 1 Take a look at the sills of used Japanese cars - everything seems to be fine, but upon closer inspection we will see small through holes. Alas, the bodies of even the famous “Japanese”, and with them, alas, the “Koreans”, if the damage to their paintwork is not repaired in time, are capable of rotting through and through in one Moscow winter season (“thanks” to caustic deicing agents)

Example No. 2 Take a look at the bodies of the oldest Peugeot and Citroen that you can find - they may have round “ulcers” with peeling paint, in the middle of these “ulcers” you can even discern brown fragments (yes, yes - this is a corrosion coating) , but... there will not be a single through hole on the body! Of course, if the case is completely neglected or the repairs were carried out using barbaric methods (heating the sills with a blowtorch and pulling out dents using “tendrils”), then holes may occur, but for this the car will need to drive through the Moscow “cocktail streets” for several years without washing or repairing paintwork , which only happens to the most careless owners!

Historical information: in 1975, the world's two first cars with fully galvanized bodies were born - these were the Peugeot 604 and Porsche 924. The German chemical concern BASF took part in the development of the technology. Since then, all Peugeots and Porsches have been "stainless".

A fragment of a Peugeot 604 advertising brochure describing the process of galvanizing the body.
Thus, if damage to the metal appears on the surface of a car with a galvanized body, then after some time rust will inevitably appear at the source of the damage. There's no escaping this. The zinc layer gives you much more time to repair this damage than if this layer is not present. The damage must be repaired in any case, and the sooner the better!

And don’t listen to the stories of all sorts of “garage storytellers” that they say he drove such and such a car with a deep scratch for 5-10 years and there wasn’t even a hint of rust... This is a myth! Such an owner is a slob, a dirty person and a chump: after all, if he cuts his hand, he will immediately run to smear it with brilliant green or stick a band-aid on it... but the car itself cannot do this!

Outwardly, a rather neat Japanese crossover of a reputable brand in the conditions of Moscow has rotted almost to the core in 7 years! Clearly the owner's fault. I had to look after

Rules for choosing high-quality galvanization

When choosing a roofing material, you need to look not only at the color and quality of the front surface, but also the back side. Corrosion usually starts on this side, since it is thinner and does not have a protective polyurethane coating.

Under what conditions are galvanized sheets stored? What condition are they in? Scratches, dents and chips are not acceptable. They should not show signs of incipient corrosion. Inattention to detail during the selection, purchase and installation of a roof leads to why the roof rusts. Material already affected by rust is laid on the sheathing, and the weather will simply continue this process. Destruction can occur both through the fault of the manufacturer, if he used low-quality raw materials, and through the fault of the builder, if he made mistakes during storage.

What to do if the roof is rusting

Even a very high-quality coating does not guarantee complete protection against corrosion. Even a galvanized roof made of high-quality material will rust. What to do in such a situation depends on the area and depth of the damage. If the material is so rotten that holes are visible or it crumbles when touched, then the coating must be replaced completely. If the damage is minor, when only small dots or stripes are visible, the roof can be repaired.

Repair means removing rust and painting. Mechanical cleaning is not permitted to avoid scraping off the zinc coating. To perform repair and painting work, use a special solution and cloth. Afterwards the surface is coated with primer and paint (enamel for metal is suitable).

Sometimes it is not the corrugated sheet itself that rusts, but only the screw heads and washers. In this case, they need to be unscrewed, the holes treated with a solution to remove rust, and new ones installed. You need to insert them into the same holes.

No matter how high-quality the roofing material is, sooner or later there comes a time when it becomes unusable. A galvanized roof also begins to deteriorate over time. The paint coating is crumbling and covered with rust. If the builder did not make serious mistakes during storage and installation, and the material is really high quality, then a galvanized roof will last more than 10 years. However, if it turns out to be of low quality, then the roof will have to be replaced after 2-3 years. Therefore, choose and purchase roofing material only from those companies whose products comply with GOST.

How to avoid corrosion

Dealing with rust is difficult and most likely you will have to contact a specialist. In addition, this struggle can be costly for the car owner. There are several tips to help prevent corrosion damage to your car:

The car should be washed once every 1-2 weeks, especially in winter, when the streets are being treated and the amount of dirt increases. If there are salts on the car body, it is recommended to add soda to the water. It can neutralize salt.
The bottom and wheel arches must be cleaned of dirt at least once a week. If necessary, these parts are coated with anti-corrosion.
In case of damage to the body, chips or scratches, it is recommended to fix the problem as soon as possible.
Use a special wax for the exterior of the car. This will help increase the durability of the paintwork and prevent corrosion of the body metal and metal parts. Since part of it is washed off with each wash, a specialist recommends waxing once every 1-2 months.

Today, the automotive market offers a huge number of different car models from different manufacturers. Of course, as we have already said, more than one auto manufacturing company can guarantee that your vehicle will not be subject to corrosion. But auto experts have formed a certain rating of stainless cars that are least susceptible to corrosion.

Sources

https://cars-rating.ru/legkovye/10-samyh-nerzhaveyushhih-avtomobilej
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