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Do pressure washers used on cars cause any damage? If they don't cause damage, and I buy one, which do you recommend and what's the best technique for their use?
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They can deform panels if you stand too close, and whatever you do don't put your hand in front of the nozzle to test the pressure. Only a fool would do that ;-(
I have had a supermarket cheapo for the best part of a decade and it still works ok, Best technique is to aim it at the car and pull the trigger.
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I've stripped the paint covering the underseal under my wheel arches by using one. I've heard they can force water past door seals and oil seals.
I now only use it if my car used for trialling comes home really muddy and then carefully.
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I don't have one, so can't offer advice. However, one neighbour of mine appears to use his washer on full blast to clean his cars top and bottom; another uses his more gently on the underside only.
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Company I worked for had its own garage and filling station. Employees with company cars could just take petrol and use the pressure washer using a pass key.
I used to wash my car with the pressure thingy regularly but always found it didn't quite get it clean and on one occasion it did damage the paint on one sill.
I'd not be in a rush to use one but then I know others find them satisfactory. I prefer to walk round with a bucket and sponge and then rinse off with a conventional hose. Can't imagine it takes much longer.
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>>Do pressure washers used on cars cause any damage?<<
Used incorrectly and without common sense, yes. Otherwise, not unless you buy one which is way too powerful for the job.
In 13 years using them from big steamers to the little Karchers I use now, ive never managed to cause damage to a car.
The things to watch out for are stone chips ( best to keep the nozzle 18 ins away from a stone chipped panel and use chemicals to remove things like flies ) and also alloys which have been repainted as the paint is never as tough as the factory finish and can lift esp at the edges if its not been refinished properly.
What I often see with non-pros are the nozzle 3 ins from the paintwork and also having it pointed square-on at the paint. I was taught all those years ago that a 45 degree angle is best and its never failed me so far.
The key to a good result is using it in combination with effective chemicals because quite often people will get the nozzle closer and closer to the car to try and get that bit more off when actually, a decent chemical will do far more than proximity will. It also must be accepted that you still need to do a little work by hand rather than expect the PW to do it all.
You read a few stories from time to time about damage caused, but seriously, the damage is caused by the ignorance of the user - forcing water past seals is about angle, proximity and perhaps the condition of the seals.
Convertibles often leak and this is just that the seals arent designed for high pressure water so you angle the nozzle down away from the seals rather than point it at them.
Tyres can be cleaned but better to use a good chemical and a brush to do the hard work rather than attack it purely with the PW.
For work, I use the cheapest Karcher on the market with the extended hose, it is more than capable of washing a car and ive never felt I needed more. I do use it with Autosmart chems though as without any chemicals, no pressure washer is the answer on its own and if you want to avoid damage as I like to, a bit less pressure and smart chemicals get a safer result.
Problem with technique is that its kinda automatic, you dont think that much about it when you have been doing it so long! I was always taught to hold the lance high and point it downwards in addition to the previously mentioned proximity ideals. 10-12 ins is usually enough distance wise to be safe.
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Very good test on the Gadget Show the other week - Kracher was found to be the best. There might be a link on their site.
Thanks for the good experience based write up Stu
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These things that use cold water are ok for washing mud off but if you want it nice and clean hot boiler water is required with detergant.
Those diesel opperated machines is what you need.
This thing here at work will do a nice job of the works van and the paint is still fine even with neat detergant which it should be a weaker mix!
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like stu i use proper cleaners followed these days by a good wide hosepipe after i found the big knob that turns the mains water supply up its so powerful the hose is like a squirming snake if you let it go
preparation as always is the key
always remember to drain a power washer if left out in sheds etc as water in them can freeze and cause them to crack,likewise always give them water pressure before you turn them on,oh and the cheaper ones kick the pipes off after a whiles use too
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>>.....,likewise always give them water pressure before you turn them on,oh and the cheaper ones kick the pipes off after a whiles use too
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I unscrew the pressure hose before parking the PW in my shed.
Having turned off the unit and the water supply, use the trigger to release the pressure prior to attempting to unscrew the hose.
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>>always remember to drain a power washer if left out in sheds etc as water in them can freeze and cause them to crack,likewise always give them water pressure before you turn them on,oh and the cheaper ones kick the pipes off after a whiles use too<<
Sound advice. Ive found Hozelock fitments pretty good under water pressure, the cheapo stuff is useless ( Hozelock is insanely expensive for what is essentially a bit of plastic with some tiny bits of rubber ). Also use the yellow heavy-duty hose, lasts ages.
I tend to run the water through my Karcher for a few minutes until the air stops coming through adn I also run the hose before attachment for about 20 seconds to get the air out of that.
Not running the machine dry drastically increases its lifespan, typically a year in my hands but I had one that went just short of two years. Usually the electrics fail before the motor does tbh, but at £70 they are pretty much a consumable, cant be doing faffing around fixing them.
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>> one which is way too powerful for the job
>> big steamers
I use a 3000PSI diesel/electric steam cleaner the size of a wardrobe to do the lorries at work, coupled with autosmart truckwash chemical mixed down at about 15 to 1 - occasionally the drivers will nip onto the wash bay and blast their cars down, usually taking some paint off the bumpers in the process. It strips wax nicely too, but none of their cars are waxed anyway ;) If I use it on mine to remove bird lime or road salt I use plain water only and I keep the lance moving rapidly across the surface.
The main use for such a high pressure is to blast the grime off truck curtains and air deflectors 14ft off the ground - I suppose I angle it at 45° as well but like Stu I don't really think about it now. The joint from the hose to the lance eats O-rings in about 10 hours of use, apparently because it's not designed to be used with such a high working pressure.
Last edited by: Dave_TDCi {P} on Mon 25 Apr 11 at 13:41
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The joint from the hose to the lance eats O-rings in about 10 hours of use
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>>>>>.interesting
i had an o ring keep blowing on the transit on the diesel pump which meant it was blowing a gallon of diesel a minute onto the road until you realised the needle was going down on the dash quicker than old navy could say dive dive dive
anyway the answer was the o rings you buy in a box from the factors or whatever basically are rubbish,i sourced an original o ring from an engine reconditioner that was an original oe part and the pumps been sound this last 14 months,maybe your company uses substandard o rings too Dave_TDCi {P}?
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Pressure washers - Robin O'Reliant
