«Stainless» cars: Body galvanizing types
The body of the car is made mainly of steel. And steel is a thing that rusts pretty quickly. To slow down this process, the body is painted and varnished. But the paint is an unreliable thing: a small accident, dry branches of bushes or a chip, and now there is no paint, and the body is not protected by anything. So came up with zinc.
Panacea a thin layer
Galvanizing is when steel is coated with a thin layer of zinc. This can be done in different ways. Some ways are better, others are worse — about it in a couple of paragraphs.
It should be understood that galvanizing does not guarantee that the body will not rust. There are such types of galvanizing, which are galvanizing only in words, so to speak, for advertising and marketing purposes. But even good quality galvanizing will not save from corrosion, it will only delay the start of rusting of steel.
The fact is that when the body is left without paint and varnish (for example, in the place of chipping), corrosion begins to destroy zinc, not steel, rust does not appear. But it is only from time to time, because when zinc is destroyed — and sooner or later he will be destroyed, corrosion proceeds by the destruction of the steel.
How long the chip will be without rust depends on many factors, not just the quality and thickness of the zinc layer. For example, humidity and temperature. On average, the rate of destruction of the active zinc layer is from 1 to 6 microns per year, and the thickness of the zinc coating on different machines ranges from 2 to 15 microns. Faster corrosion occurs where wet. Or, for example, under the mud.Hot dip galvanizing
Now about the types of corrosion treatment. The best galvanizing is hot dip galvanized. With this method, the body is lowered into the bathroom with hot (from 500 to 4000 degrees Celsius) zinc. A layer of zinc is usually obtained about 10-15 microns. So zinc is mainly expensive machines and not all, because it is quite a complex and expensive process. The warranty on the body, galvanized in this way, is usually 15 years. And once the warranty is such a body can be considered almost eternal. Examples of hot-dip galvanized machines: most modern Porsche, Audi, Ford, Volvo models.
The second method of galvanizing is galvanizing. It is cheaper and more common. Most galvanized machines are galvanized in this way. The body is lowered into a zinc-containing electrolyte, through which current is passed. The result is a very uniform galvanizing layer from 2 to 10 microns. The warranty against corrosion for such a body usually in the region of 10-12 years. This method of galvanizing is used by almost all manufacturers of non-budget cars: Opel, Toyota, Mazda, Volkswagen, Mitsubishi, Chevrolet, Nissan*
This type of galvanizing is widespread not so long ago. Around the same time, when the ball was ruled not by engineers, and marketers.
The technology consists of mixing highly dispersed zinc powder into the soil. The galvanized body, in this case, can be considered only formally, because of zinc, in fact, not on the body, and in the ground. There is no primer (if the scratch is to the metal) — no protection. Corrosion protection of such «galvanizing» is very small. Great warranty the body manufacturer, in this case, does not, usually limited to the General guarantee of the paintwork. In this way, galvanized for the most part budget cars: Renault Logan, Lifan, Chery, Great Wall, Hyundai, Renault Logan, UAZ, VAZ.
This type of galvanizing is rare and only among a small number of inexpensive models. The essence of the method is that the zinc soil is covered with steel at the rolling stage. The protective properties of this method of galvanizing cannot be called outstanding. Especially poor protection will be in places where it is wet and after accidents and damage. In this way, galvanized mainly cars Kia, Renault.
Importantly, what treatment was in the body of full, partial, or only the nodal connections. Naturally, it is best when the whole body is galvanized. But for the manufacturer of budget cars and models is expensive, so they are often partially zinc. For example, only wings, thresholds.
Very very economical car manufactures tailor every penny, LinkOut only the joints (welding joints and fixtures, for example).
As you can see, galvanizing discord, and for each specific model requires clarification. On the Internet, you can find information about how and in what years of production zinc or other models (and whether it was galvanized at all). Sometimes, for example, in the case of «Logan», in the first years of galvanizing was partial, and then complete.
In General, two conclusions should be drawn from all this. The first — even rust galvanized machine. And rust at different speeds depending on the weather, the care of the owner, temperature, external influences such as reagents and dirt and so on.
The second conclusion — do not believe the statement of marketers that the body is galvanized. Galvanized it can be purely formal, and it is necessary to look at the facts — the method of galvanizing and the manufacturer’s warranty on the body. The greater the warranty, the better the probably galvanized body.
*Information is collected from open sources and may contain inaccuracies. The method of galvanizing can vary from year to year, from plant to plant, from model to model. To get the accurate information you need to look for information on a specific model, year of manufacture and plant.