Updated: Nov 12
When weekend warriors want to step up their car cleaning game, they often turn to clay and clay bar kits. Clay is exciting. It makes paint super smooth, rips out contaminants no other tool can, and can even make defects less noticeable by removing trapped dirt. Like a gateway drug, this simple material is the beginning of many DIY detailing arsenals – clay is even the reason for the start and survival of many detailing businesses. Because of its mystical abilities, clay is often entirely misunderstood in the general consumer market. Today, we’ll remedy this misunderstanding with a crash course on the anatomy of the clay bar.
What: Like many great things in the car world, detailing clay was invented in Japan and brought to/copied in the US. Most consumers will find it cut into handy 100-gram chunks sold in kits with detail spray and a crappy microfiber towel. At the professional level, multiple grades of clay from “fine” to “aggressive” can be used to tackle different contaminants and surfaces. That said, consumer-grade clay that is light to medium in “aggressiveness” will effectively handle the vast majority of detailing applications.
Why: Claying is ideally done after ferrous metal decontamination and before polishing to remove extremely tiny “embedded contaminants.” Clay is flat and sticky. Thus, it does a great job of pulling out or breaking down anything stuck in the paint. Detailers add this extra cleaning step to enhance the finish achieved in polishing. If not for clay, contaminants would be dislodged in polishing. These contaminants make refining paint more difficult (and can even make it impossible altogether). Even so, most consumers can observe the benefits of clay without polishing. Smoother, cleaner paint reflects light better and stays cleaner longer. In other words, you’ll see more shine for more time.
When: More shine for more time sounds too good to be true, right? It kinda is. Contrary to popular belief, you should not and do not need to clay your car “every wash,” “every month,” “every year,” or “every whenever-you-feel-like-it.” Clay is abrasive. Therefore, claying causes marring that will (unless polished) be detrimental to your car’s shine and dirt-repelling abilities. There is no “general guideline” or “magic number” for claying. Most of the sources claiming that there is such a time-period are also probably trying to sell you clay or claying services. Instead of getting on some arbitrary regimen, use your scientifically calibrated fingertips to determine whether or not your car needs claying. If you properly protect your car and don’t leave it filthy for months on end, you should almost never “need” to clay it.
Where: Pretty much any smooth surface can be clayed. However, you’ll want to focus on the horizontal parts of your car (i.e. the roof, hood, trunk lid, and windshield). These areas tend to be more heavily contaminated, but, again, you must consult your scientific fingertips to determine where claying is necessary. An iron dissolving chemical (the stuff that turns purple) can also help identify areas of heavy contamination.
How: Ensure your paint and clay are lubricated with a slip solution of some kind. This could be a detail spray, waterless wash agent, or even a quality car soap & water (“clay lube” products are unnecessary unless you’re using a specialty system like Nanoskin Autoscrub and Nanoskin Glide). Move the clay left, right, up, and down as quickly as you want around the vehicle. Avoid using lots of pressure. Downward pressure increases marring. Once the surface is smooth and silent, move to a new area until the vehicle is complete. Periodically check the clay to ensure it hasn’t picked up anything big and scratchy. Knead it as it becomes contaminated and DO NOT drop it on the ground.
Rapid fire tips:
1. Never purchase a “clay bar express wash special” just because you feel like it. First and foremost, you should confirm that your paint needs claying. Is it rough to the touch? Can you hear a towel moving across the surface? If so, you do need clay. Secondly, in most high volume car-wash environments, you will not get your money’s worth from a “wash & clay” service. Claying takes time and does more harm than good when performed haphazardly under tight time constraints. It’s not necessarily the fault of the employees, it’s just a non-ideal claying environment.
2. If you buy clay or a clay kit, don’t use the entire bar all at once. Break it into fourths (or at least in half) and make a thin patty with each piece. You may use the entire bar as each patty becomes contaminated, but you won’t run the risk of dropping an entire clay bar on the ground. As you’ve likely heard, clay that’s touched the ground belongs in one place: the garbage.
3. If you clayed your car and it wasn’t all that bad, save the clay in a specific baggie for non-paint applications. Clay that’s been used lightly on paint is still good for glass, wheels, painted brake calipers, or the undersides of your rocker panels/bumpers.
4. Speaking of, you should clay your glass even if you don’t plan on adding a hydrophobic sealant/coating product to it. Smooth glass is more hydrophobic and your wipers will last longer and work better.
The importance of proper car maintenance through the use of clay barring extends across the spectrum of car ownership, from car enthusiasts caring for their vehicles to professional car detailers tasked with maintaining picture car rentals for production companies. Regardless of the context, ensuring the longevity of vehicles exterior condition requires effective detailing practices, with clay barring emerging as a universal tool for maintaining a smooth and pristine exterior finish.