Why its important to rinse

After washing a vehicle, the recommended step is to rinse the soap off. But not everybody actually knows why its recommended. Why not just dry off the soap and with it, the vehicle? Rinsing is one of the many steps of washing a car properly. And shouldn’t be skipped, unless you are using a rinseless of waterless washing products.

The steps of properly washing a car

When washing a car, there are certain steps that are recommended to take.

1. (optional) Use snowfoam to loosen the dirt
2. (optional) Rinse off the snowfoam (and with it, a fair bit of dirt)
3. (optional) Wash the wheels with a brush/washmitt
4. Use a washmitt (or similar) to wash the vehicle (do not use the washmitt you used for your wheels)
5. Rinse off the suds from washing
6. Dry the car
7. (optional) Apply dressing and/or protection where applicable

As you can see, there are 2 times when rinsing is done. After the optional snowfoam, and after washing. In both cases, rinsing is done for the same purpose.

Why rinse

Rinsing is done to remove the loosened dirt. When you apply the optional snowfoam, it loosens up dirt. That dirt is loose, but it is still on the surface of the vehicle. The dirt is mixed with the soap/water mixture. By rinsing off the water/soap mixture, you also wash away the loosened dirt. If you rinse after a snowfoam, you wash away the dirt it has removed. When you start to wash the vehicle with a washmitt (or similar) you don’t have to deal with the dirt that has already been washed away. The washmitt stays clean for longer, and you minimize the risk of swirls or other surface imperfections.
When you rinse after washing the car, you again wash away dirt that has been loosened up by the washmitt and the soap/water mixture. Apart from the dirt that is in the washmitt, the soap/water mixture on the vehicle is not 100% clean. There will be some dirt in this. If you don’t rinse off the vehicle, the dirt will be dragged around when you start to dry the vehicle. To prevent this, and minimize the risk of swirls, you rinse the vehicle after washing.

How rinsing can help to dry the vehicle

If a vehicle has a clean surface, and a protective product has been applied that influenced the surface energy of the vehicle, the water will sheet of the surface. Because the attraction between the water molecules is larger then the attraction with the surface underneath, the water that is sliding off the surface will drag the rest of the water with it. If there are no contaminants on the surface (of imperfections in the protective layer), the water will slide off the surface in one big sheet of water. Hence the term: “sheeting”.

Exceptions

There are a few situations in which rinsing is not needed, this would be when you work with a waterless wash or when you use a rinseless wash. The Garry Dean method is considered as a cross between waterless and rinseless wash, and also counts as an exception. In the process itself there is a substitute for rinsing.