After a good high-pressure wash, the car seems to be clean at first glance. However, if you run your finger critically over the paintwork of the vehicle, you will notice residual dirt in most cases. The so-called grey haze or static dirt always remains adhered to the car namely after pure high pressure washing without brushes. But why is this?
The Sinner Circle (named after the surfactant chemist Herbert Sinner) describes the four factors that lead a car wash to perfect results. These include time, temperature, chemicals and mechanical systems. These factors are interdependent and can be partially offset against each other, but not eliminated for a perfect result. The static dirt is a particulate type of soiling with a particle size below 2μm, which adheres to surfaces due to its charge. This dirt is not completely removed even by very high pressure used in a high pressure wash, nor with strong chemicals. With the right chemicals and proper water pressure, purely touchless washes can indeed achieve good results, but the static dirt remains stuck on. Consequently, it is important not to dispense with a minimum level of mechanical treatment. The use of the brush lance helps in the case of self-service washing.
Some car owners would prefer to refrain from using brushes for vehicle washing, because they are afraid of getting scratches in the paintwork. This fear is unwarranted if the brushes and detergents are high quality and the water pressure is set correctly. After some washes, you may find that the brushes have left marks on your car. Although these may look like scratches, they are not physical damage to your car. Rather, they are part of the brush material that has become soft at the high temperatures during the wash. You can easily remove them with a detergent. The paintwork is not affected.
In fact, such brush abrasion is very uncommon when the brushes are made of high quality materials and are resistant to high temperatures. This applies to all WashTec brushes, which are temperature-resistant up to 83 degrees Celsius. Some inferior models from other manufacturers, however, melt even at 51 degrees Celsius and leave the scratch-like abrasion on the car.
In fact, scratches can occur during the brush wash stage – but only if errors occur. For example, in poorly supervised car washes, objects may get stuck in the brush fibres, such as pieces off aerials or windscreen wipers. These can cause scratches on the next car. However, responsible employees or car wash owners will immediately remove them if they do ever happen to break off and get stuck during the wash cycle.
It is also possible that, especially in the lower section of the car, small scratches occur owing to sand getting into the brushes here. This can be prevented by a thorough pre-wash. Also dried-up brushes can cause this damage due to limescale deposits and dry biofilms. You can avoid this by rinsing the brushes with water for at least seven minutes after the car wash has not been in use for a long time.
However, if you still prefer not to use any brushes at all for car washing, a Touchless system provides an ideal solution. With WashTec's SoftCare² Pro Touchless system, thanks to intensive high-pressure technology with what are known as turbo nozzle spot-spray nozzles and effective chemical pre-treatment, even without brushing, it is possible to achieve good cleaning results. Rugged and round surfaces, which are difficult to reach by brushing, are cleaned well in this type of wash. The SoftCare² Pro Touchless system can be used both as a pure high-pressure unit or a combined system with the gentle SofTecs washing material, allowing users to choose between “touching”, “touchless” or a combination of both options.
In high-quality and well-managed car washes, nobody has to worry about the paintwork being scratched by the brush wash. Conversely, this method of washing is the only one that actually removes static dirt completely. However, an automatic car wash without brushing is basically still more gentle than washing cars by hand. Motorists who value cleanliness but shy away from brushing, find a good alternative in the Touchless system.