Given the size of the investment, it certainly makes sense for a car owner to ask questions about whether or not a car wash is safe for their vehicle. The best answer typically comes from a car wash manager who can effectively explain the wash process and equipment and detergents being used. To assist in those conversations, we're sharing the following information from Tommy Car Wash Systems. Thanks to Tommy for allowing us to share.
"Swirl Marks and Car Washes? What's Really Going On."
There’s nothing more American than the beloved personal automobile and the freedom, independence, self-sufficiency, and success they’ve come to represent. People LOVE their cars and rightly want to see them taken care of, and properly understanding the threats to vehicles (both cosmetic and functional) and how to head them off is key to keeping a car running and looking great for decades to come.
This brings us to the topic of the day: swirl marks. These are circular microscopic imperfections on the surface of different vehicles, best seen on black or dark blue cars when illuminated by a single light source (like the sun). They are not to be confused with cracking or spider webs, both of which lie beneath the clear coat and are a result of imperfections or micro-fracturing in the paint itself. Most cars develop scuffing to one degree or another over their lifespans and they can be resolved with professional treatments.
The question, of course, is whether or not swirl marks are caused by automatic car washes like the Totally Tommy tunnel?
Even the most cursory search online (or conversation over dinner) reveals the incredibly strong feelings many people have about the relationship between these abrasions and automatic car washes (friction cleaning washes in particular). It’s often just assumed as common knowledge. Car Wash brushes are said to be too harsh, scraping vehicles and marring the clear coat, or the brush material (and sometimes even the water in the high pressure hoses) is said to become impacted with dirt and grit, which in turn is spread from vehicle to vehicle, resulting in scratches.
But the truth is more complicated and much more interesting.
First off, car wash materials and cleaning instruments have changed with time, but what hasn’t changed is the need for car was operators and engineers to balance the cleaning power of the wash against the resilience of the car itself. Back in the early days of car washes and up until recent decades, most of the wash power came from scrubbing action rather than chemical or detergent action or wash pressure. When most of the cleaning had to be done with brushes and friction, the degree of friction was ramped up with brushes that took off more of the dirt but had a greater impact on the surface as a result. Older style brushes were more abrasive and often worked with less lubrication, which in combination with single stage paint jobs, made minor scuffing a regular occurrence.
But today this damage is virtually unheard of and well-maintained modern car washes have a number of safeguards in place to prevent swirl marks or customer damage. Advancements have been made in in water filtration, detergent application, high pressure washing, and in the friction cleaning material in particular.
Today’s soft cloths have forgone the nylon brushes that were famous for leaving brush marks in the 1970s and 80s and instead rely on a closed cell foam material that lacks any structure that could conceivably capture dirt or grit, OR a highly engineered cloth made from densely woven cotton or polyethylene microfibers. The foam and microfiber (which feels fuzzy like yarn with the consistency of a heavy cardstock and is often used for underwater curtains or faux-kelp in major aquariums) are both continually primed with body soap and fresh water, removing any debris and providing much-needed lubrication between the brushes and the body of the vehicle. They’re safe to use and the overwhelming majority of patrons never have any issues—even after repeated washing.
But what about the occasional patron who does report scuffing and swirl marks?
There are a number of theories, each of which probably holds truth in certain situations.
Single stage paint: High quality foreign cars in dark blue or black are sometimes still painted with old-fashioned single stage paint, resulting in a more fragile clear coat that is more easily affected by regular washing materials in both hand washes and automatic washes. Antique and high end cars should always be cleaned with great care.
2. Revealing wear and tear: As a car wash cleans a car it can reveal imperfections and scratches that had previously been obscured by dirt and dust. The cleaner the car, the more easy it is to spot regular lines and nicks that can result from blowing sand, particle debris on highways, and even damage from improper hand washing practices like one-bucket washes, dishwasher soap, and artificial sponge use (which have been shown to be far more damaging to vehicle exteriors than most auto owners realize).
3. Perception bias: Nearly every car on the road has marks of one kind or another, regardless of how it is cleaned or maintained. Usually you only see them when you are looking for them, and then when you spot a problem it’s all you can see! Because smart consumers look very closely after their car washes they are more likely to spot preexisting damage and blame it on the wash—even if the type or pattern of damage is clearly inconsistent with the action of the car wash’s components.
4. Wax layering: New cars fresh from the dealer usually have a heavy, brand new coat of professionally applied wax to protect them from the elements, improve their gloss, and disguise those very same cracks and spider-lines we mentioned in the opening paragraph. As these brand new vehicles are driven that wax begins to break down, and when they go through the car wash the first time exposure to detergents and friction cleaning can actually thin and polish the original wax further, bringing out existing imperfections that had not been visible before (and often enraging the new car’s owners). A fresh coat of professionally applied wax easily corrects the issue, which is normally only present on very dark vehicles or vehicles with certain ‘flat’ paint tones.
If the brushes or chemicals in the wash were to damage a vehicle, the pattern of damage would be expected to follow very specific patterns matching the motion and action of the equipment used, and your average swirl marks don’t fit the bill. Incidents of car wash damage are extremely rare and when they do often they most commonly involve other factors.