Washing Your Car: Difference Between DIY and Professional Detailing

by | Sep 21, 2022 | DIY vs Professional Detailing Series | 0 comments

We all love our cars to look great, but it’s the washing and drying process that causes the majority or scratches and swirls in our paint. In this part of our “DIY vs Professional Detailing” series, we’re going to discuss washing your car. In particular, we’re going to look at how most consumers and car washes wash your car, versus how a professional detailer takes the car wash process to a whole other level and why it’s important you should too.

DIY Car Wash Methods

There are a few flavors of DIY car wash we’ll discuss today, including a bucket wash and automatic car wash.

Automatic Car Wash

Perhaps the worst-case scenario (as far as your car paint finish is concerned), you’re driving down the road and decide to stop at an automatic car wash. While quick and convenient, these are absolutely detrimental to your clear coat! Automatic car washes use spinning brushes, high-pressure wash, and very harsh chemicals to remove dirt from your car. These do way more harm than good, stripping off any protection you may have previously had, and leaving a litany of swirls in your clear coat. Is the $14 really worth it after all?

automatic car washes are bad

If you care even a little about your vehicle paint, never ever use an automatic car wash with spinny things that touch your car.

Soap & Bucket

I think we’ve all done each at one point or another. We get lured into the fancy packaging at the auto parts store, the promise of a gold-class car wash with rich conditioners in one bottle! We get home and fill up a big bucket with tap water and soap, wet the car down to remove dirt and dunk the wash mitt or brush and get to work. Those further into the game know the more common tips, like working from the top down and even using the two-bucket method, we’ll discuss these more later, but there is much left on the table as far as car washing goes and just working from the top down or using two buckets won’t keep you from further damaging your paint entirely, but they’re good practices as part of a more holistic car wash solution.

Ultimately, the purpose of a good car wash, should be to remove surface dirt and contaminants from your vehicle, without damaging the surface. So every step should be viewed through that lens of “am I leaving swirls when I do X” Let’s look at how a reputable professional washes a vehicle, and the extensive steps taken to preserve your paint and coating from scratches and swirl marks.

Professional Car Wash Detailing Methods

Professional detailers use a variety of specialty tools when washing your car. But more important than the tools, are the order the steps are taken and the techniques used once they go hands on. There are a lot of factors that go into the best way to wash your car without scratching it and getting it 100% correct, starting with not washing in direct sunlight.

Wash your Car in the Shade

Washing your vehicle in the shade is imperative. If it’s wicked hot out, you’ll want the surface to cool a bit before proceeding. If the surface is too hot, you won’t have enough working time with your chemicals to properly wash and dry without leaving marks. A professional either has an enclosed shop space to work, or a mobile detailer will put up a canopy to provide the ever important shade.

Use Deionized Water

Water from the tap always contains some amount of solid materials in the form of minerals, and professional detailers know this all too well. If you were to wash your car with tap water and leave it to air dry, there’s a strong chance you’ll have water spot marks on the surface. These mineral deposits aren’t just unsightly, but contribute to swirl marks during the wash and dry process. Professional detailers will use a water deionizer inline during most stages of the the wash and rinse process to avoid water spots and swirling.

Water deionizer spot free car wash

Chemical Decontamination (Many get this wrong, take note)

So we are in the shade now, the surface is cool and we have a source of water free from dissolved solids. The next step for a pro is Chemical decontamination. Chemical Decon is the process of removing as many surface contaminants as possible before going hands on to literally scrub them off. To accomplish this, professional detailers commonly use a foam cannon attached to a pressure washer to create rich suds that begin to emulsify and break down dirt on contact.

Many beginners opt to start with wetting the vehicle first to “knock off” as much as they can before using the foam cannon. But this is a mistake! By wetting first, the chemicals inside of the foam have a harder time penetrating the contaminants. The foam cannon should be used on the dry vehicle surface without wetting to get the most effective results.

Another common error made with chemical decontamination, is not letting the chemical dwell long enough. Each soap manufacturer is different but generally speaking, 5-10 minutes of dwell time is needed to loosen and remove contaminants effectively.

Under Pressure

It may seem like a good idea at first, but using high pressure to blast away car grime is a bad idea! A pressure washer on high pressure or with too narrow a tip can quickly blast through your clear coat and paint in a split second. This is especially true on newer vehicles with softer paint, or in areas where the paint is thinner such as outside corner style bends. Because of this, professional detailers use relatively LOW pressure to rinse off the chemical decon, taking special care to use a wide fan and not get too close to the painted surface. Experience is the detailers friend here washing your car.

Iron, Bug, Tar and Sap Removal

Iron contaminants from road and brake dust get deeply embedded into your clear coat, and along bug guts, tar and tree sap, these contaminants are among the most difficult to remove. Now is a great time to start softening these materials and lifting them from the clear coat.

Most iron removers contain ammonium-thioglycolate, a chemical compound that oxidizes ferrous metals, allowing them to be pulled from the clear coat finish. The professional detailer will spray iron/fallout remover all over, but focus on the areas behind the wheels down the side of the car, this is where the majority of iron deposits land. After several minutes, the active ingredient will begin to turn from clear to purple as it bleeds down the side of the vehicle.

Washing your car

Before and after iron remover treatment on car wheels. Close up of automobile tire during the removal of ferrous residues. How to avoid iron contamination. Rims turn purple after applying iron remover


This is also the time where bug remover and tar and sap remover spot treatment occurs. These chemicals are very aggressive due to the nature of the job at hand and should only be used where needed. Most importantly, they should never be left to dry on your vehicle (have we mentioned to work in the shade yet?).

A quick rinse again after preps us for a critical step, Mechanical Decontamination.

Mechanical Decontamination

This is where the rubber meets the road… err… chenille meets the clear coat. We’ve gone ahead and removed as much dirt and grime as we could before ever touching the vehicle, this is a big win but the most dangerous portion of washing your car has arrived. You see, it’s whenever we put hands on, whether it be with Chenille (my personal preference), sponge, or microfiber, there is a greater than 0% chance of scratching, swirling or marring the painted surface. That’s why we wanted to remove as many contaminants as possible in the previous steps.

Tire Time! You can choose to wash your tires any time, but we like to do them first to allow more dry time. Timing aside, the most important thing to note here is to use separate supplies for your tires. Separate bucket, separate brushes and mitts, etc. Wheels and tires contain the majority of brake dust and some of the most harmful contaminants to your painted surfaces. Your wheel and tires supplies should never touch your vehicle paint, ever. Keep a lookout for our DIY vs. Pro Tire article in the future.

Now, soap selection at this point is important. Using a pH neutral soap when washing your car will go a long way to not degrade any existing waxes or sealants. But for a previously ceramic coated vehicle, a pro will be using a car shampoo that contains some SiO2 (Silica Dioxide), the ingredient in ceramic coatings that contribute the rock hard, extremely hydrophobic finish it leaves. Using this premium shampoo will restore those properties further and extend the life the coating

Pro-Tip: When washing, be very gentle and wipe only in straight lines, never wipe in circles to avoids swirls.

two bucket wash method


At this point, most professionals opt for the two bucket method. With a typical single bucket method, water and soap go into one bucket, you dip your mitt, wipe the dirty vehicle, then dunk the mitt back into the wash bucket. All of the dirt from the mitt is now polluting your wash water and mitt every time you go back for more. With the two bucket method, one bucket will have the suds and the other will be clean water. Once you get your mitts soapy and wipe down a section of your car, you dip in the rinse bucket first to remove as much dirty and contamination as possible, then dip in the soap bucket and move onto the next section of the vehicle.

Taking the two bucket wash method a step further, professional detailers use some sort of grit trap in the bottom of each bucket. Scrubbing the wash mitt on the grit trap while rinsing removes more dirt and traps the particles on the bottom, helping to preserve the clean water and mitt as much as possible. There are also caster wheels for the bottom of the bucket and bucket caddy’s that keep your most used tools close at hand. A big time saver, and helps keep wash mitts from ever touching the ground.

Speaking of wash mitts, there are many options here, but it seems Chenille is taking the lead here. The caterpillar like nobs are super soft, hold a ton of soap and perform well. They’re fairly inexpensive to boot!

Pro-Tip: Wash your car in small sections and only from the top down, saving the lower half of the vehicle (especially saving the front bumper and behind the wheels for last). This greatly reduces the amount of contamination in our buckets. You can’t be too careful here.

Car washing and drying causes swirl marks

It’s us washing and drying that causes swirl marks in our vehicles paint. Taking these steps helps avoid them as much as possible.

What’s the Difference?

As you can see, the difference between a DIY Car wash and a professional washing your car is a stark contrast. A professional uses a great deal of time, a variety of chemicals, tools, and techniques to take great strides towards reducing the amount of swirl marks we cause during the car wash process. A simple soap bucket and wash mitt and hose just don’t compare and will absolutely cause more harm than good. Professional exterior car washes take considerably longer than washing your car yourself at home as a result, and with A LOT less swirl marks.

How to Close the Gap?

It’s not difficult to bring your DIY Car Wash game up to the pro level within a reasonable budget! Simply needs to take the principles we learned above and improvise a few of the tools and you can get quite close!

Start with procuring some new supplies.

  • A few 5 gallon buckets, ideally with grit traps. Mark each with their purpose using permanent marker (Tires, Rinse, Wash, etc.)
  • Chemicals. You’ll want a foam car wash soap for chemical decon along with some iron remover, and bug remover. There is no best household soap to wash cars with, go with a purpose built products here.
  • Foam Gun or Foam Cannon. If you have a pressure washer already, go for a foam cannon, if not, you’ll need a foam gun. They work almost as well as the cannon but will connect to your garden hose.
  • Inline Water Deionizer. You don’t need to spend hundreds on a big wheeled unit here, a smaller inline deionizer costs much less and screws right into your water spigot, and your hose then attaches to the deionizer. Say hello to spot free rinses!

note: all links contained in this article are not affiliate links, just links to decent consumer products that are easy to find and work well.

Final Thoughts

There is a stark contrast between the results you typically see at home and the results a professional detailer can get while washing your car. But unlike other areas of the vehicle (such as paint correction), there are few barriers to entry, a shallow learning curve, and not too large of an investment to take your car wash game up a few notches. This one is worth investing in, as you’ll notice it every single time you wash your vehicle. Conversely, not using methods like these, you’ll be doing damage to your paint every single time. Good luck and take care.

Check out our other DIY vs. Professional Detailing Articles Here!