What the heck is it with car pressure washers?!

If its not working at 2 inches you need to add sand to the water!

 

Get it too close and the paint may come off.

RMX

 

Back in high school, a classmate decided that he'd make some extra money using his father's power washer on neighborhood vehicles. His first "customer" was a neighbor with a brand new F-150. This guy wanted to get the truck really clean, so he cranked up the pressure and proceeded to strip the chrome right off the front bumper! That business didn't work out so well.

 

haha, that must of sucked. I've shot washers at cars all the time, but the dirt NEVER comes off, you are right!

 

I've only used them for washing parts, transmission cases, engines, etc... Never used them for any painted body panels on a vehicle, I never understood why someone would try that anyway.

 

Sounds just like a "touchless" car wash which is pretty much a waste of money.

 

I've always heard never power wash a car. It blasts water so far into nooks and crannies that you can't ever get it dry. And the first trip after the wash will have water spraying all over the car from all the nooks and crannies.

I don't know who's right but I've always just let water run straight out of the hose with no nozzle. Or if there's a nozzle, I don't apply much pressure.

 

The touchless car washes aren't as good as washing the thing by hand (or whatever) but they do a decent enough job in my experience. It's all about that foamy soap they spray on

 

Not unless you physically touch a car with a soapy mitt or similar you aren't cleaning the surface properly. A sprayer is too risky for damaging the paint.

 

Expecting water to wash your car....get a f'n towel. Use some elbow grease, it won't kill ya

 

Adding a soap (detergent) to your water will reduce it's visctosity and essentially make it "sliperier" (allowing it to get into the cracks/etc better) than straight water.

Also, WI dirt (clay based) is much more determined that most.....

 

Its definitely the soap. Adding just water and no car wash soap in the washer will just get the mud off, which may get dirt as well. For a normal dirty car without using soap its pretty much like leaving the car out in the rain if you think about it.
My choices: 1: Hand wash yourself. 2: Have seombody (whos insured or that you know and trust) hand wash it. 3: Coin op. 4: Touchless carwash.
I usually do #3, as I dont know anybody that actually spends the time being as anal as me while hand washing. When I do get time though its #1. Havent used a pressure washer on a car though, other than a coin op.

 

I take my girlfriends car to a self washing bay as there is no hose access (legally) at her
condo. Power washers generally are not a good way to wash cars.

The hi-pressure spray may remove some dirt but not the fine grime or bird droppings.
Its mostly air which does nothing.

I basically use the coin ops to get the car wet, add soap, then I hand wash it with a washmit
and rinse throughly with the spray washer.

Most of the people who use these self wash bays end up removing the dirt during the
drying process which is like wet sanding your car.

The hose and alot of water is the way to go.

 

The problem lies in that there is an ionic bond between the paint and the dirt/hydrocarbons that have accumulated on it. To break this bond, you must use a detergent for sure and the only way that the detergent can do it's job properly is by you applying the soap to a dry surface. In other words, don't wet your car first then apply soap to it, that will do nothing. Turn your soap on and wait for the soap to come out the wand then apply at about a 12" distance starting at the bottom and working your way up with a smooth back and forth motion. Then rinse from the top down and you will get good results. Obviously, don't do it in direct sunlight and only do 1/2 the car at once otherwise the soap will dry in some areas before you get around to rinsing it. Also, the better your wax job on the vehicle, the better your results will be as the ionic bond will be weaker. With a 2100 psi machine, I would assume that you are running about 2.5 gpm, so stay between 4"-6" away from the vehicle and keep moving. We wash our company trucks with 3000-3500 psi all the time and they have graphics all over them and we have never as much as peeled a graphic. It is all in the technique (i.e. using your head).