Car wash

The history of commercial car washes in the United States began in 1914. People used manpower to push or move the cars through stages of the process. The name is credited to Automobile Laundry in Detroit, Michigan, opened in 1914 by Frank McCormick and J.W. Hinkle .[4]

Manual car wash operations peaked at 32 drive-through facilities in the United States. The first semi-automatic car wash in the United States made its debut in 1946. A facility in Detroit, Michigan, used automatic pulley systems and manual brushing.[5]

Dan Hanna, encouraged by car washers in Detroit, made his own car wash in 1955 called the Rub-a-Dub in Oregon. In 1957, he formed the Hanna Enterprises and eventually reached about 31 locations. In 1959, Hanna operated his wash rack until he made the first mechanized car washing system. Hanna saw expansion as the popularity of his mechanized system spread throughout the city.[5]

By the mid 1960s, Hanna Enterprises established itself as the main manufacturer of car washing equipment and materials. This includes the Wrap-Around Brush, Roller-on-demand Conveyor belt, soft cloth friction washing, several ways to wash the tires, and a recirculating water system.[5]

The 1970s introduced the automatic wheel cleaner and the polish'n'wax.[5]

Modern car wash facilities, whether tunnel, in-bay automatic, or self-serve, detergents, and other cleaning solutions used are designed to loosen and eliminate dirt and grime. This is in contrast to earlier times, when hydrofluoric acid, a hazardous chemical, was commonly used as a cleaning agent in the industry by some operators.[10] There has been a move in the industry to shift to safer cleaning solutions. Most car wash facilities are required by law to treat and/or reuse their water and may be required to maintain wastewater discharge permits. This is in contrast to unregulated facilities or even driveway washing (at one's home), where wastewater can end up in the storm drain and, eventually, in streams, rivers, and lakes.

A chemical car wash, also known as waterless car wash, uses chemicals to wash and polish car surface. This method is claimed to be eco-friendly.[11] It is recommended only for cars with light dirt accumulation to avoid paint damage.[12]

Mechanized car washes, especially those with brushes, may risk damaging the exterior finish. Paint finishes have improved as also car washing processes. More facilities utilize "brushless" (cloth) and "touch-free" (high-pressure water) equipment, as well as modern "foam" washing wheels made of closed-cell foam.

Car wash tunnel at the ABC filling station in Joensuu, Finland

The first conveyorized automatic car wash appeared in Hollywood, California in 1940.[13] Conveyorized automatic car washes consist of tunnel-like buildings into which customers (or attendants) drive.

Some car washes have their customers pay through a computerized POS, or point of sale unit, also known as an "automatic cashier", which may take the place of a human cashier. The mechanism inputs the wash PLU into a master computer or a tunnel controller automatically. When the sale is automated, after paying the car is put into a line-up called the stack or queue. The stack moves sequentially, so the wash knows what each car purchased. After pulling up to the tunnel entrance, an attendant usually guides the customer onto the conveyor. At some washes, the system will send the correct number of rollers automatically, based on tire sensors. The tire sensor lets the wash know where the wheels are and how far apart they are. On other systems the employee may guide the customer on and press a 'Send Car' button on the tunnel controller, to manually send the rollers which push the car through.

Prior to entering the automated section of the wash tunnel, attendants may prewash customers' cars.

A vehicle exiting the friction zone of the wash. Visible are side brushes, wrap-around brushes, the conveyor, and a high-pressure rinse arch.

The car wash will typically start cleaning with chemicals called presoaks applied through special arches. CTAs, or "chemical tire applicators," apply specialized formulations, which remove brake dust and build up from the surface of the wheels and tires.

In some car washes, the presoak application is followed by an empty space or idle zone. Wheel cleaning equipment, such as sill brushes or high-pressure wheel blasters, may be placed in the idle zone. A sill brush (also known as a wheel brush or tire brush) consists of an 8-foot-long brush assembly that is pushed against the car's wheels and door sill area. Brushes typically use flagged bristle, as dirt is usually most heavily concentrated on the lower parts of the car. The material on a sill brush may have alternating lengths or use a material that is intentionally mounted off-center to allow wheel surfaces of various depths to be cleaned. Sill brushes rely on the rotation of a customer's car's wheels in order to achieve complete wheel contact. Similar to the CTAs, wheel brushes often only activate when the customer buys a wheel cleaning upgrade. Some car washes use wheel-rim disc brushes in addition to or in place of sill brushes. These assemblies extend out towards the wheel and follow it at the same speed as the conveyor while rotating at high speeds to clean the wheels. At the end of a car wash's presoak idle zone is often a high-pressure arch that directs water at a vehicle's surface.

A typical "tunnel" car wash viewed from the inside of a vehicle

Mitters are ribbon-like components that suspend cloth strips or sheets over the tunnel while utilizing motion to increase friction against the car's surface. The friction zone may also include specialized front grill and rear brushes. Older automatic washes - a majority of which were built prior to 1980 - used to use brushes with soft nylon bristles, which tended to leave a nylon deposit in the shape of a bristle, called brush marks, on the vehicle's paint. Many newer facilities use either a soft cloth or a closed-cell foam brush, which does not hold dirt or water, thus is less likely to harm the painted finish.

A glass car wash building containing an inbay automatic and freestanding blowers

After the main friction zone, some car washes have a dedicated care zone. Prior to entering the care zone, the car is rinsed with fresh water. This is immediately followed by a series of extra services. In many car washes, the first of these services is a polish wax. After the polish wax application is typically a retractable mitter or top brush and, in some cases, side brushes or wrap-around brushes. Next is a protectant, which creates a thin protective film over a vehicle's surface. Protectants generally repel water, which assists in drying the car and aiding in the driver's ability to see through their windshield during rain. A low-end wax or clear coat protectant follows the main protectant. A drying agent is typically applied at the end of the tunnel to assist in removing water from the vehicle's surface prior to forced air drying. After the drying agent, there may be a "spot free" rinse of soft water, that has been filtered of the salts normally present, and sent through semi-permeable membranes to produce highly purified water that will not leave spots.

Dryers may be present in a variety of forms, such as stationary gantries with a contouring roof jet or as small circular assemblies with nozzles of various shapes and sizes mounted on arches. Mitters, side brushes, top brushes, and/or wraps outfitted with chamois- or microfiber-based material may follow the dryers.

At "full-service" car washes, the exterior of the car is washed mechanically, by hand, or using a combination of both, with attendants available to dry the car manually and to clean the interior. Many full-service car washes also provide "detailing" services, which may include polishing and waxing the car's exterior by hand or machine, shampooing, and steaming interiors as well as other services to provide thorough cleaning and protection to the car.

A touchless in-bay automatic car wash

Like soft-touch car washes, touchless car washes are automated, with the vehicle passing through a tunnel where it is cleaned. However, touchless car washes do not use the foam or cloth applicators that soft-touch washes use, instead relying on high-pressure washers to clean and rinse the vehicle. Sensors utilized by these washes allow for a more precise clean along with the vehicle's exact shape.[14] To compensate for not physically contacting the vehicle, touchless washes use higher pressures and more caustic detergents than ordinary car washes.[15] Because the vehicle is not physically touched during a touchless wash, the vehicle is at a lower risk of being damaged. However, touchless washes have a harder time cleaning off tougher materials or reaching difficult-to-reach locations on vehicles, and their usage of stronger chemicals can potentially damage a vehicle's paint finish.[14][16]