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How to "beat" rust on the car

How to get rid of rust

It happens when a punctate but rather deep dent is formed on the roof of your car. It looks like a large branch with a sharp knot or a small stone from the balcony above the parking lot ... And what I saw in a few weeks at the place of this dent is not exactly pleasant - rust :( The editors of shram.kiev.ua1 will tell you how to deal with rust on a car and picked up tips from your personal practice to remove rust.

Rust is a general term for the determination of iron oxides. In colloquial terms, this word applies to red oxides formed during the reaction of iron with oxygen in the presence of water or moist air.

There are other forms of rust, for example, the product formed during the reaction of iron with chlorine in the absence of oxygen. Such a substance is formed, in particular, in the reinforcement used in underwater concrete pillars, and is called its green rust. Several types of corrosion are distinguishable visually or by spectroscopy, they are formed under different external conditions. Rust consists of hydrated iron (III) oxide Fe2O3 · nH2O and iron metahydroxide (FeO (OH), Fe (OH) 3) . In the presence of oxygen and water and sufficient time, any mass of iron is ultimately converted completely to rust and is destroyed. The rust surface does not provide protection for the underlying iron, in contrast to the formation of patina on the copper surface.

Rust is usually referred to as a corrosion product of iron and its alloys, such as steel. Many other metals also corrode, but iron oxides are commonly called rust.

So, what is it - all familiar rust, or to put it more scientifically - iron oxide Fe2O3. Only iron or its alloys, which are oxidized after the metal is combined with water, can rust. Metal corrosion is an electrochemical process in which electrons are emitted from the anode (its role is played by a metal car body), which through the electrolyte (water even with a minor admixture of salts) reaches the cathode (metal parts that can accept electrons). As a result of this process, the iron of the car body is converted to iron oxide - that is, it rusts.

Understanding the process of corrosion and gives us the tools to deal with it. Since the car body is made of iron, the anode and cathode will always be there, but with the electrolyte we have to do something. By the way, precisely because of the greater saturation with various salts of chemical reagents that utilities use in the fight against ice, the machine begins to rust strongly during this period (the electrolyte is very saturated and of high quality).

The process of dealing with corrosion is multistage and is divided into three fundamentally different directions.

The first path is passive. Since we cannot replace the iron of the car body with, for example, plastic (rather fragile) or metals without iron (expensive), we need to cover the metal of the body with an insulating coating - i.e. primed and painted. This process is the most effective way to prevent corrosion - but you need to constantly monitor the integrity of the protective coating, check it for minor damage - cracks, bumps, chips. If they are detected, measures should be taken immediately to restore the coating.

Also related to this path are measures related to the cleanliness of the car - washing (once every two weeks) and periodical (after every second washing) waxing of the car’s coating — water flows along the wax more quickly.

The waxing is the second way to fight corrosion, called active, that is, the use of various physical and chemical coatings on the metal. Various mastics, sealants, protective lubricants and anti-corrosion sprays are used for this. There are many of them, but the essence is the same - the creation of an additional protective layer in addition to the main paintwork. Basically, these preparations are used on the most dangerously corrosive areas of the car - the bottom, sills, arches. Additional protection is effective only if it is applied to absolutely clean and dry surfaces, otherwise water may remain under the protection film, which will continue the corrosion process.

The third way - electrochemical - is used less frequently, primarily due to the high cost and the need for constant power supply of an additional installed electronic device (cathodic protection station). Roughly, we can say that due to the change in the electrode potential, the processes of corrosion in the car begin to take place only in a certain place, and now the cathode is not the body of the car, but a special electrode, which will rust instead of it. A newer, purely electronic system, “Final-Coat”, appeared, forming a uniform flow of free electrons on the back of the car, which do not interact with the metal atoms.

All three ways to protect the body perfectly complement each other, but still sometimes there is a miss and the appearance of rust shows itself in all its brown-reddish beauty. Here it is already necessary to act promptly, since it is very easy to start the corrosion process throughout the entire body, but it is much more difficult to get rid of it.

First of all, you need to carefully remove rust . To do this, use a weak solution of alkaline acid, which is processed rust, and then it is removed mechanically (sandpaper or metal brushes). Carefully follow the instructions, because the acid is quite aggressive and just eats away rust from the inside, and this process must be stopped in time.

Also effective are so-called rust converters or modifiers, which, as a result of a chemical reaction, convert iron oxide to iron tannate, which is a more stable substance. High-quality modifiers contain polymers and act as a primer. The disadvantage is that if the metal oxide is not processed in its entirety and remains, then the corrosion process will continue.

Now in specialized stores it is easy to find the same rust converters of various kinds. The cost of their content is not high. The processing is very simple, first sand the damaged area to a pure metal, then apply the composition of the rust converter and leave for several hours depending on the instructions. Do not be alarmed when the cleaned area is green - the rust modifier is working.

Then everything is standard - the place from which rust was removed (or transformed) is puttied, primed and painted. Actions are repeated if necessary. In my case, I decided to use the modern and most reliable and stable, in my humble opinion, method - conducting galvanization. The method is also an electrochemical process, and as a result of the electrolysis of a solution containing zinc, a protective zinc-free protective layer appears on the surface of the iron.

Theoretically, it was possible to prepare for this process independently, but I preferred to buy a ready-made set consisting of two bubbles with liquids (plus auxiliary things). The first one is designed to remove rust and degrease the surface (I removed the rust mechanically - it was not much benefit - but still ...). Then I wetted a special tampon in the contents of the second vial - a solution of zinc salts - and using the attached wiring connected to the battery, I started the electrolysis process.

As a result, I was: a) terribly pleased with my technical and chemical advancement; b) made up for the psychological loss from the recruitment of a young chemist that I had not bought in my childhood; and c) got a thin layer of protective zinc coating of gray color on the body (and I have a bubble with my paint).

So, it is possible and necessary to fight rust on a car, and now you also know how.

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