You can hardly remove iron powder with a basic car wash. This is the special item for easily removing such contaminants.
When train wheels and railroads rub together, you put on a brake, or you are around a metal processing factory, invisible iron powder flies in the air.
If the iron powder adheres to the car body, it causes serious symptoms such as that it prevents a gloss after a car wash or doesn't allow you to wax smoothly.
Prepare a clear snack package film after a car wash. Rub your car surface with the package film as shown in this picture. If the surface feels rough, that is the iron powder stuck on the surface.
It adheres to the surface as shown in the figure A. It's difficult to remove with a general car wash using a car shampoo, so you need to work through the process of removing iron powder.
Literally, this is a cleaner made of clay.
First, knead and flatten it.
Be sure to use the clay bar AFTER washing the car.
In order to avoid scratches, gently rub the body with the clay bar, adding water. You will be surprised that iron powder which a regular car wash fails to remove is easily cleaned off.
As the clay bar gets dirty with iron powder, knead and fold it to continue to use a clean surface. You can use one clay bar 3-4 times although it depends on how dirty it is. Stop using when the clay bar gets entirely dirty regardless how many times you have used it.
The car body becomes very smooth after removed iron powder, which helps you easily wipe off wax and coating agent and dramatically improves the results.
Scrubbing hard ends up damaging the surface. The clay bar can easily pull out iron powder and absorb it, so there is no worry about scratches.