There are many reasons to use a mechanized car wash, from simple convenience to cold winter conditions that freeze dirty hand-washing water on the car before it can be rinsed off. All machine car washes have their limitations: The lower parts of the vehicle’s sides and the rear panel are likely to have some dirt, road salt and residual detergent left in place. That said, any method of removing harmful atmospheric and road deposits is preferable to leaving them to accumulate.
Types of Mechanized Washes
In some mechanized car washes, the vehicle is parked inside a short tunnel and various washing and drying sequences take place as a large frame passes repeatedly over the car. An alternative design requires the car be parked on a pad that slowly moves through a much longer tunnel; a series of separate frame-mounted machines pre-wash, wash, dry and polish. A concern with both types is their aggression. Detergent mixes are typically harsher than those recommended for hand washing, and the water jets are so strong they can strip expensive and carefully applied wax finishes.
100 Percent Touchless
A 100 percent touchless car wash is designed so that nothing solid comes into contact with the vehicle. Touchless car washes use pressurized water to pre-wash, wash and rinse the vehicle, after which jets of air -- not straps of cloth -- dry the surface.
A Touchless Option
Do-it-yourself pressure-washing facilities are becoming common. In these, the car is parked in a bay and the driver uses a pressurized water jet to wash and rinse the vehicle, a process that is particularly beneficial for vehicles with heavy road-salt buildups in the wheel wells. This option is effectively a touchless wash, because -- unless the user chooses to finish the process by drying and polishing with a cloth -- only water comes into contact with the vehicle.
In soft cloth car washes, the vehicle passes through several curtains of material in sequence. The process typically begins with pressurized jets of water used to remove heavy debris and granular dirt from the surface, followed by a rotating drum that passes over the vehicle as detergent is applied. Numerous straps of soft cloth are attached to the drum -- carpet strips are not uncommon -- that help the detergent to work. A second drum, to which chamois strips are attached, usually passes over the car to finish with a polish.
Higher-end operations use special cloth made to resist the accumulation of dirt on its surfaces. This, and the constant flow of fresh water over the work area, reduces the potential for scratching that is inherent in hand washing. The straps of cloth slapping back and forth across the paint can nonetheless be disconcerting, and can leave swirl marks.
Retooling Older Car Washes
Some older car washes have been partially updated to include a final treatment where a soft cloth drum dries and polishes the washed car. Branding this kind of operation as “soft cloth” is deceptive. These still use rotating brushes to wash, and such brushes are renowned for leaving scratches on hoods and roofs as they climb over the car. Side brushes -- intended to wash wheels -- can damage trim and side mirrors.
- Photo Credit Ryan McVay/Lifesize/Getty Images