Desert sand covers our cars, blood rain makes a layer of dirt out of it. First thought: wash the car. But beware! We explain how to avoid scratches.
It hits the lantern parkers hard, especially when they stand under linden trees instead of under lanterns. Road dust mixes with sticky droplets, and with bad luck comes bird droppings. A layer forms on the paint that can etch into the surface. Blunt surfaces are the result.
It gets even worse when the wind brings us sand from the Sahara - in Spain this weather phenomenon is called "calima" or "lluvia de sangre" ("blood rain") because it usually accompanies precipitation - but this time in was the case in very few regions. A low-pressure area causes winds that transport the desert dust from Africa to Europe. This is not uncommon, but in March 2022 it was particularly severe, in Germany it hit southern Germany in particular. Many cars looked like they had been through days of desert rallying.
Pre-washing with lots of water is particularly important
If you see your wheels like this, you immediately think of a car wash. Technical experts from the ADAC consider this to be useful in principle, so that the sun cannot burn the layer of dirt. But be careful: Anyone who lends a hand now risks scratches, because this will usually happen at home with too little water. Moreover, washing cars in the garage entrance or even in the front yard is forbidden in most municipalities; According to Thomas Drott, Managing Director of the Federal Association of Gas Stations and Commercial Car Washes in Germany (BTG), Section 1 of the Water Resources Act ultimately only allows a clean car to be washed with clear water. And washing systems are generally much more environmentally friendly: they collect the water used in settling tanks or containers of up to 100 cubic meters, treat it and reuse around 90 percent of it; the dirt goes to the sewage treatment plant, says Drott.
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But there is no shortage of other ways to clean the car in Germany: The BTG estimates the number of professional car washes at around 14,000 portal car washes, 2400 car washes and around 3000 car washes. And the differences between the plants are important when the car is covered in sand. In the widespread portal systems, the car stands still while the washing technology moves along it, in the car wash it is the other way around. Here the car rolls past brushes and nozzles on a conveyor belt.
In both cases, a pre-wash with enough water is essential for the careful removal of mineral deposits such as sand from the Sahara - otherwise there is a risk of scratches, because otherwise sand threatens to rub over the paintwork like emery paper. In portal systems, a high-pressure cleaner is usually available for this purpose. If not, in this case a washing process should be avoided there. The powerful jet of water is often available in appropriate self-service boxes – which, if in doubt, you don't want to use when you're out and about in fine thread; Irrespective of whether there is sand or not, the high-pressure cleaner should be used extensively on the wheels, wheel arches and the lower areas of the front and rear aprons. The rollers of the systems usually do not reach these points very well.
Portal system without a high-pressure cleaner is taboo with sand
If there is no high-pressure cleaner on a portal system, then the only thing that helps in the case of a Sahara alarm is driving to a car wash, where employees or corresponding devices usually rinse off with the high-pressure cleaner before entering the conveyor belt complete. According to studies by ADAC and GTÜ, car washes are usually superior to portal systems in terms of washing results - which is mainly due to the pre-wash. This also helps with dust and salt crusts in winter, which severely damage the paintwork and attachments if they are not removed regularly.
After the pre-wash, rags and rollers protect the paint
On average, every car in Germany gets six to eight washes a year - except for the sand boom. For the whole of Germany, they add up to 200 to 300 million transactions; the bulk of this is accounted for by the portal systems. Experts allay fears that new cars shouldn't go into the car wash. The painted surfaces of the car are already so resistant upon delivery that the soft polyethylene rags of the washing rollers can do almost nothing to them - always provided they do not carry any dirt with them from the previously washed car.
How to recognize good car washes
With such a large selection of washing options, the question naturally arises: where should I go, where can I get good washing results for my money? A reference can be a seal of quality that the Association of the German Automobile Industry (VDA) awards. It currently adorns around 1360 systems nationwide.
If the car wash you are standing in front of is missing, it does not have to mean that it does not offer good cleaning performance. A scrutinizing look helps with the assessment: Do rust and dirt determine the first impression? Are there torn wiper blades in the system and rubbish outside? Does it smell or are the washing brushes dirty? Then the system probably does not deserve good maintenance, it is better to continue. Drivers of large off-road vehicles and SUVs have to be particularly careful anyway.Because their expansive cars sometimes don't fit into older, narrow rollover car washes. In addition, they are often only equipped with a few washing nozzles for the underbody and remove dirt sticking there rather insufficiently. This is a disadvantage, especially for cars that are occasionally used off the paved road.
Convertible drivers, on the other hand, can rest easy. Joachim Jäckel, chairman of the BTG, says: "You can drive a convertible through a car wash without scruples. Today's care products no longer stick the fabric of a soft top." That was different a few years ago, when waxes were primarily used for preservation after washing, which had to be removed from the windows with special cleaning cloths before you could leave the car wash. According to the care experts at Sonax, convertible drivers should also impregnate their soft top twice a year. Always assuming that no bird comes flying and leaves its business on the roof - because that must be removed immediately. Ideally, the affected area should also be re-impregnated when it is dry again. When applying the impregnation, the car should not stand in the blazing sun. However, once the agent has been sprayed on, heat and sunlight help the protective effect to develop fully.
When do you need which program?
But does it really have to be the full washing and care program? In the case of heavy soiling, at least a premium wash seems advisable so that the dirt is really completely removed and the paintwork, which may already have been slightly attacked, is then given new protection against dirt and UV radiation with a seal. There is one exception to this rule: this applies to cars with a matt finish, which should mainly be cleaned with a basic care product. Because the matt surface reacts sensitively to care products and sealants. In the long run, it tends to become semi-matt, especially since the rags of the washing rollers also show a polishing effect on these special paints. Basic care is also sufficient if the car is only averagely dirty. By the way, even if there is a colored film over the paint. After all, the foils also age faster if aggressive dirt has time to deposit and accumulate on the surface. As a rule of thumb, however, four washes a year should go over the paint or foil with all options. In this way, the outer skin of the car retains a basic level of protection against aging too quickly.
Check the pollen filter after the Sahara sand
After washing, ADAC recommends cleaning the sheet metal surfaces that are otherwise covered by hand with a well-dampened cloth when the doors and flaps are open. In view of the current Sahara sand, you should wash the rag often so that the dust is not carried on.
The club also advises inspecting the cabin filter (also called pollen filter) now and replacing it if necessary, especially if it hasn't been changed for a long time. Because if it was already loaded and has now also gotten the sand, it's full. Then he unloads his load into the interior.
Depending on the car, you can change the cabin filter yourself. There are now filters for some models that even hold back some gaseous contaminants (mostly filters with an activated carbon layer) or are designated as anti-allergenic, according to the ADAC.
Remove bird droppings and dead insects immediately
Regardless of the sand, bird droppings are the final enemy for the car paint and must be removed immediately - either with a sharp jet of water or with a completely soaked newspaper. It softens the dirt and takes most of it away from the paintwork when it is pulled off. Don't scrub! Dead insects can also be removed in this way. They put many car washes to the test if there is no thorough pre-wash.
Old water-based paints are less hard
The water-based paints that have been used for a good 20 years are still not quite as scratch-resistant as the acrylic-based paints used up until then. Even very well-maintained car washes can therefore leave the finest scratches on the paint surface over the years. But they can be polished out. Before coarse-grained polishes are let loose on the paintwork and rubbed in with great pressure, you should remember that the topcoat on the sheet metal is only a few thousandths of a millimeter thick. Especially on sharp body edges, it is frighteningly quickly polished away and you look at the primer. That's why tact is required: Firstly, when choosing the polish - there are different agents for new and aged paintwork, for solid colors and metallic tones - and also when it comes to the force with which the polish is applied. The more pressure is applied, the more paint is removed. So less can be more, even when it comes to car care.
The most important rule when cleaning the car from Sahara dust: Use a lot of water! This protects the paint and the glass surfaces from scratches when removing the tiny sand particles. A pre-wash is therefore essential. Car washes are preferable to portal car washes. They offer the best cleaning performance. A seal of quality from the VDA certifies a high quality standard. Around 1,300 systems are currently allowed to bear this seal.