OT Power washing cars

[keno]

I live on a dirt road. My car is always in some degree of dirtiness. My solution has been, for the most part, to have a dirty car. I have made a late new year's resolution to consider washing my car with some frequency above zero.

In that connection, the idea of using a power washer has come up. While the low psi washers, like 1,400 psi, are advertised for use on cars, there is a school of thought that says that the use of a power washer can ruin a car's finish. I won't even mention use on a bike, even on a Serotta with an iron finish.

I need some experienced-based truth.

keno

[cs124]

Water pressure is only one factor.

Also, how abrasive is the medium, ie dirt, on the surface of the car?

How close do you hold the nozzle to the car? The washers put out a very fine spray. The water droplets lose their velocity very quickly after leaving the nozzle. Stand back a few feet and you'll be fine.




Sigh...You are lucky to even be asking this question. We have stage 3 water restrictions down here. No washing of cars except at commercial outlets that use recycled water, no watering of lawns, watering of plants twice a week and only during certain times, no hosing of driveways or any external paving. The reservoirs are at 35% of capacity after probably 5 years of way below average rainfall.

[cs124]

...to actually answer your question, I used a small Karcher pressure washer on my cars (BMW 3'er and VW Golf) for years. No problem with the paintwork.

[jhcakilmer]

Well, I don't know about you, but here they use a lot of salt on the road. So I power wash our car weekly. The salt really packs in the wheel wells, and that's where it starts to rust!

I'd say the salt, and packed dirt will cause a lot more damage, then the water pressure! I use the brush on the paint sometimes, and you really should get to close to the car, since I'm sure the high pressure water can damage the paint.

Also, I always see lots of pro team mechanics using power washers spraying down there bikes. I'm sure they take care around certain areas.

[Erik.Lazdins]

I have never experienced a power washer harming a cars finish any more than normal washing. If the car starts out clean and has a good wax on, the power washer even on cold setting will wash off the dust layer that accumulates very quickly.
After snow and ice melts and the roads dry, a power washer is invaluable to keep the undercarriage clean.
The best power washers have burners in them to heat the water, however a 1,500 or so psi should be all most people would want and isn't a lot of money out of pocket.

They are handy to have around for other projects than washing cars (wood decks etc.)

[fierte_poser]

My opinion is that you are going to micromar/scratch the clearcoat when using a pressure washer due to the fact that the high pressure water is driving the dirt into the clearcoat before it gets washed away. I don't think it will ruin the finish, however. One place I would be very careful using a power washer is if the clearcoat has cracked or peeled.

I have two cars. One I let my neighbor power wash, and one I don't. He's always looking to be useful. ;)

[keno]

Thanks for the responses. I think that I'll be getting a power washer. My car is a 2000 Audi A6 with 137,000 miles, which I hope to get another 100,000 out of. I don't think that my major concerns center around the finish - we're talking macro here.

fierte_poser, my recently moved neighbor was helpful to my lawyer, if you get my drift. You don't know how lucky you are.

keno

[Hardlyrob]

where it shouldn't be.

The water proofing on cars including gaskets and membranes are not designed to deal with 1400PSI water. Strange things can happen - like a leaking sunroof several days after the car was washed because the gasket leaked and the sound insulation was full of water. The ignition system can also collect water in unsuspecting places - like inside an ingnition coil :crap:

I grew up with high pressure sprayers and farm equipment. Granted the quality of the finish on 1960's and 1970's tractors is not close to a car today, but we did learn that cleaning with a high pressure spray and paint bubbles from rust can effectively strip paint to bare metal as fast as you can blink.

I would be very gentle with the pressure wand, and don't get too close until you are sure of what the likely outcome is.

Paid tuition the hard way...

Rob

[oldguy00]

I've been using pressure washers on both my car (jeep) and all my bikes for several years now. I've used the typical $200 hardware store versions, as well as the more powerful ones you find at the wand wash drive-in car washes. Never had any probs whatsoever. I do take a few minutes to dry the bike and oil the chain, etc.