Will A Pressure Washer At A Car Wash Bay Remove Touch-Up Paint?

There's something so very serene and satisfying about getting your car washed. To see all the muck and grime accumulating over tens, hundreds, or thousands of miles worth of driving wash away into oblivion is so very pleasing, that it has few equals in the world for feeling. However, pressure washing does bring with it some dilemmas to consider, such as whether it'll strip away all your touch-up paint 

Of course, who hasn't had at least one run-in with needing to touch up their car? Stone chips and scratches are a common conundrum with everyday car ownership, but it's made a lot easier knowing that most paint touch-up solutions are easy to find and apply these days. Nevertheless, you're not always so sure if it works as well as you think it might, and whether a blast of water will ruin it all.

Does Pressure Washer Have An Effect On Paint?

The first question that we can answer is - does using a pressure washer affect your car's original paintwork? To that, we say 'Maybe'. A lot of enthusiasts and loving car owners promote the use of a pressure washer to keep your car looking as fresh as it came from the factory. But on the other side, we have folks telling us that pressure washing a car could actually damage it. 

In fact, both sides are right on this one, and while there are a lot of upsides to pressure washing done right, there also risks (and consequences) attached to not doing it properly. It's so much of a risk, that Consumer Reports themselves once wrote a recommendation against pressure washing your car, as it could cause more harm than good. Here's a look at both ends of the story...

Using A Pressure Washer - The Right Way

Pressure washing a car, owing to the high pressures that it can exert on the bodywork, is a great way to remove all the stubborn dirt and grime that could otherwise not be dislodged with a simple garden hose. The process involves a specialised hose to deliver a steady, high-powered stream of water, and there are more than a few variables to consider with pressure washers.

Essentially, this will factor in how safe a particular pressure washer will be to use for a car, and where does it get too far to a point where it might wash away your paint or newly-applied paint touch-up. A particular note before we get started, do bear in mind your safety before pressure washing. The PSI ratings are strong enough, in some cases, to cause serious injury. 

PSI and GPM - Both of these relate to the flow of the water, with PSI (pounds per square inch) defining the pressure at which the water is released, and GPM (gallons per minute) telling you how much water in volume is released. For most cars, you're recommended to use a pressure washer with a rating between 1,200 to 1,900 PSI, and 1.4 to 1.6 GPM. Multiplied together, and you get a value of around 1,900 to 2,800 "cleaning units". Too much, and it could strip away the paint and coating. 

Electric or Petrol - Most pressure washers are either petrol, or electric powered. In general, you can expect that petrol-powered pressure washers will be able to deliver more power, or in other words, more pressure. For car-related washing, you're recommended to use electric pressure washers within.

the PSI and GPM ratings from earlier. Using an overly powerful petrol pressure washer could not only strip away your car's paint and coating, but potentially even crack the windows and plastic trim.

Nozzle Angle - When using a pressure washer, there are a variety of nozzles to attach to the other end that determines the spread of the water. You can often find a nozzle angle from 0 to 65 degrees, with the lower nozzle angles being more direct and targeted. When pressure washing your car, you should pick a nozzle angle that spreads the pressure and flow of the water by 15 degrees or more. Anything less, and it might be strong enough to affect the car's paint finish.

Distance - Not only must you consider the pressure and flow rate of the pressure washer, but also the distance from where the nozzle is in relation to the surface of the car. If you're standing too close, even a weak pressure washer with relatively safe PSI ratings can be too strong for the paint to handle. So, make sure that you're standing at least four to five feet away from the car when using the pressure washer.

Pressure Washing - The Wrong Way

But not all is good in the world of pressure washing your car. It's not recommended for those that have little experience to use a pressure washer, as it can cause a lot of trouble and inconveniences. Here are some examples of what happens when it all goes wrong...

1. Some owners fail to clean off the car's surface thoroughly enough in their first run. This leads to dirt and other small particles gathering on the car's paintwork. When combined with being forced by the pressure washer, it can turn heavily abrasive as it scrapes and scratches the paintwork.
2. If the paint is already chipped or scratched, the high PSI from the pressure washer might cause these to open up, or for the paint to peel off around it.
3. Too high of a PSI, washing from the bottom to top (instead of the other way around to clear off dirt and debris), or putting the stream of the pressure washer in one place for too long, can strip away or cause significant scratching and other damage to the paint.

In the end, we'd like to reiterate the common adage of washing your car the old-school< way; a couple of buckets of soapy water (proper car washing shampoo, not dish soap, mind), and a soft wash mitt. For paint touch-ups, it's highly suggested that you give your car, especially around the newly repaired and touch-up area, a good waxing to add an additional protective layer once the paint's all dry.

Then, consider washing it, as we recommended earlier, a couple of days after the waxing process to properly give the touch-up a bit more time to dry up. While pressure washing does have its fair share of upsides, such as using the stream to clean away the stubborn and hard-to-reach spots like your car's undercarriage, you should leave that to the professionals.