Pressure washing car but it is still not clean

**Shine E** · 04-22-2011, 11:38 PM

I have been using a pressure washer for the past few weeks on my car. It seems to get it mostly clean, but a light dirt film still remains. The only way I can clean this off os by hand washing. Is there a way to get a car totally clean using a pressure washer only?

BTW the pressure washer is 3GPM and 2000PSI.

**tuscarora dave** · 04-22-2011, 11:50 PM

I've used many pressure washers of varying pressure ratings and have yet to get a car totally clean with just a pressure washer alone.

**DejaVu** · 04-23-2011, 02:53 AM

You need friction to remove that layer left behind after using a pressure washer. I have the same issue, and so far the only way I've been able to remove that layer is to just go over the vehicle with Optimum No Rinse and a good microfiber sponge. I'm sure regular car wash soap will work as well, but the small amount of friction between the sponge and layer of ONR or soap is what's needed to transfer the dirt film to the wash media.

**silverfox** · 04-23-2011, 04:10 AM

Once the dirt, grime, or water spot binds with the clearcoat it can only be removed by hand. However if there was a method to protect the paint from the bonding process you might be able to just wash with a pressure washer. The new paint coatings are a step in that direction.

**Matt** · 04-23-2011, 06:14 AM

Originally Posted by silverfox

Once the dirt, grime, or water spot binds with the clearcoat it can only be removed by hand. However if there was a method to protect the paint from the bonding process you might be able to just wash with a pressure washer. The new paint coatings are a step in that direction.

Yep totally agree. Pressure washing alone can never get the paint totally clean, well not with todays chemicals. If you were to find a chemical that could be sprayed on and PW'd off, then it'd be a pretty harsh chemical. I like pressure washing because it removes the large pieces of dirt and dust.

**Bunky** · 04-23-2011, 07:20 AM

Originally Posted by Matt

Yep totally agree. Pressure washing alone can never get the paint totally clean, well not with todays chemicals. If you were to find a chemical that could be sprayed on and PW'd off, then it'd be a pretty harsh chemical. I like pressure washing because it removes the large pieces of dirt and dust.

This also means that touchless car washes also do not get cars clean.

**maximus20895** · 04-23-2011, 09:32 AM

They use harsher chemicals though. Some do an okay job.

**AeroCleanse** · 04-23-2011, 11:18 AM

You could try a foam canon.

**arenared** · 04-23-2011, 11:42 AM

Personally, I would be careful with a pressure washer and expecting a vehicle to be clean. It is easy to blast off any marginal paint or chips and get water into places not meant to withstand that kind of pressure. I would use the pressure washer only to remove "bulk" dirt, then follow with a hand wash.

**jbgrant** · 04-23-2011, 12:41 PM

Originally Posted by arenared

Personally, I would be careful with a pressure washer and expecting a vehicle to be clean. It is easy to blast off any marginal paint or chips and get water into places not meant to withstand that kind of pressure. I would use the pressure washer only to remove "bulk" dirt, then follow with a hand wash.

I second that entirely. The pressure washer is a great tool which used properly will help you prevent paint damage. However, a pressure washer should be used in the least aggressive manner necessary to remove abrasive particles that are not bonded or are very lightly adhered to the finish surface with other contaminants (acting as glue). A presoak soap will make it more effective. Once you have pressure washed away anything large enough to mar the paint, rinse the car down and move on to your handwash stage. You can absolutely damage paint, trim, bearing seals, etc with a pressure washer if you're trying to make it a 1-step wash.