A car wash is a place to clean the outside, and sometimes the inside, of automobiles.
There are many different types of car washes. These are the three main groups:
- self-service that are usually coin-operated,
- In-Bay Automatics are machines that roll back and forth over an automobile while washing it,
- "tunnel washes" push or pull the automobile through a line of cleaning machines that do not move.
In a modern car wash soaps and other chemicals used are based on milder acids and alkalies. Early car washes often used hydrofluoric acid, a hazardous chemical. Many car washes are now required by law to treat and reuse their water.
There are two types of foam: polish and wax. Polish is cheaper and may be harder to rinse, sometimes becoming solid in its holding tank. Wax is more expensive, but rinses well and covers the vehicle with a lighter and puffier foam.
Rotating brushes inside a conveyor car-wash.
A touchless car wash