I see more and more places offering “pressure washing” and even “steam cleaning”. Do they do anything more than a good “wash”, and why would anyone want to steam clean under the floor? Is there any justification for private motorists to invest in this sort of kit at home?
Pressure washers are extremely good at removing all kinds of dirt, especially in places that ordinary washing with cloths and brushes cannot reach.
They do the job with less effort, in less time, and with potent effect.
They need a plentiful water supply (10 litres per minute will give you some perspective) usually drawn through a hosepipe from a tap, but with options to suck from a drum and, if desired, to automatically inject liquid soap as they work.
Though they are often associated with cleaning cars, high-pressure jets of water (don’t under-estimate their potential power) can be applied to dozens of other “cleaning” jobs in industry, manufacturing, construction, business, agriculture, restoration, health services, household settings, and even selective fire-fighting.
A taster of other potential jobs is striping flaky paint, removing rust, getting dust off solar panels, cleaning the outside of upper floor windows, washing courtyards, paths, floors, decks and steel doors, blasting termite nests, spring-cleaning chicken coops, humidifying greenhouses, and anything else your imagination can add.
Relatively small and portable pressure washers are usually powered by either electrical pumps or petrol engines. They usually have about six interchangeable nozzles for their long-reach wands, starting at No. 1 with a very fine jet that is so sharp that at close range it can engrave stone or chop a brick in half. It is certainly powerful enough to strip paint!
At the other end of the scale nozzle No. 6 produces a fine mist spray.
Car washing comes in around No 3.
Also read: Car-wash takes a new turn
The power of a water jet is greatest near the nozzle and diminishes quite rapidly with greater distance, so force is adjustable by standing closer to or further away from what you are washing. Unrestricted, the most direct sprays can reach about 20 metres. Steam cleaning has the added effect of high temperature as well as pressure – a combination that is especially efficient at blasting away grease and oil so ideal for underpans and engine compartments.
Bear in mind that some components need grease and oil, and others do not need water (e.g. alternators) so some circumspection (and fresh lubrication) is necessary (e.g. door latches).
Why the underpan?
To get rid of compacted mud that could harbour moisture and promote rust, and to get things clean enough that it is easier to work on and easier to spot cracks or tears or fluid leaks. Many mechanics are not fussy enough about dirt, and one remedy is not to give them any to work with.