Wheel & Tire Care
Why is wheel cleaning different from cleaning the rest of my vehicle?
Nice wheels dramatically enhance the appearance of any car. Modern wheels also present a substantial challenge, as heated dust particles from brake pads bombard the wheel and bake into the finish. If left on the wheel, a phenomenon known as galvanic corrosion sets in, which will eventually destroy your wheel's appearance.
Most modern wheels, in particular aluminum alloy wheels (or "mags" as they were once called), are painted with the same paint and clear-coat system used on the body of your car. Unfortunately, standard car wash soaps and household cleaners are not strong enough to break the bond between brake dust, road tar, road grime and the wheel. To properly clean wheels, the car care industry has developed three groups of wheel cleaners:
1. Acid-based Cleaners -- These are widely used by detailers, car dealers and car washes who need to clean wheels in the shortest possible time or with the least amount of effort. Acid-based cleaners are typically 2% solutions of inorganic acids like oxalic, phosphoric, and hydrochloric acid. While these cleaners pack the greatest cleaning punch, they can easily etch the surface of your wheel if allowed to dry. Clear-coat finish is subject to damage from such compounds (including acid rain, hydrocarbons, and acidic cleaners). Care must also be taken not to use them on wheels with pitted or chipped surfaces. The acid will migrate into any fissures and accentuate flaking and peeling of surface coatings.
By contrast, organic acids utilize the same chemical principles to cause the brake dust to “release,” but are easier to buffer and don’t damage wheels (or people). They are generally more expensive and therefore less common. This is the type used at Caribbean Express.
2. Acid-free Solvents -- These are mild solutions of alkaline solvent, usually ethylene glycol or butyl ether, with a wetting agent. These solutions creep under the dirt and brake dust, loosening and lifting surface grime. Non-acidic cleaners usually require some surface agitation (wheel brush or sponge) but will not etch the wheel's finish like an acid. Polished and anodized aluminum wheels (but not protected by a clear-coat) will react (dull or corrode) to both alkaline and acidic conditions. The biggest problem with these alkaline solutions is that they pose health risks (skin irritation and respiratory distress).
3. Detergents -- Generally speaking, detergents are safe wheel cleaners, but can be a little tough on tires and other rubber. Of all the active wheel cleaner ingredients, detergents are by far the safest for both car and owner. Detergents also require the most agitation (brushing) to completely clean your wheels. The benefit of a detergent wheel cleaner is that it will not harm delicate wheels and it does not pose a health risk.
Why do wheels get “cloudy”?
The principle reason modern wheels (i.e., those produced after 1990) become cloudy or dull is the breakdown of the clear coat finish. This happens for several reasons:
1. Age, and the cumulative effects of acidic and alkaline compounds that occur commonly in our environment, including road salt and harsh chemicals—heck, even contaminated rain puddles. These materials attack even the tiniest cracks, chips, or scratches, and eventually undermine the coating.
2. Failure of the clear-coat. Certain manufacturers, notably GM in the period
1998 – 2002, experimented with alternative coating materials (such as water-based urethanes). These materials did not meet the demands of everyday use and were abandoned. Unfortunately, owners of vehicles with these wheels are now discovering how these coatings fail to keep their shine. Fortunately, most of these wheels can be repolished and refinished while mounted on the vehicle, usually in just a few hours.
3. Inappropriate use of cleaners. Applying alkaline cleaners to polished (but uncoated) aluminum wheels (“billets”) will generally result in a cloudy haze forming over the entire surface. Fortunately, most wheels can be polished with jeweler’s rouge (or equivalent) while mounted on the vehicle and returned to new or nearly new condition in just a few hours. Regular polishing and waxing is required to combat the oxidation that inevitably dulls these wheels.
Can my wheels be restored to their original brightness?
Yes,usually. Most wheels that are discolored, cloudy, or dull can be restored to (or nearly to) their original appearance. Exceptions are wheels that are scratched, chipped or damaged by collision; the CNC lathes needed to repair those wheels are beyond the scope of any retail business. Most clouded wheels can be stripped, repolished and refinished while still on the vehicle. Such restoration typically requires 1-3 hours, depending on the wheel design.
How can I protect my wheels?
Clean them often using pH neutral cleaners; don’t let brake dust and contaminants accumulate for weeks at a time between washings. When clean, apply a protective wheel polish to preserve the clear coat as you do with the rest of the vehicle’s finish.
What about caked-on brake dust?
Brake dust is created by the friction between the brake pad and rotor during the normal use of disk brakes. These hot particles come flying off and embed themselves in the clear-coat finish of the wheel. If washed off promptly, these particles are relatively easy to remove. But when clear-coated wheels are left unwashed for weeks (or months!), the material “bakes” into the finish and requires significant scrubbing and chemical treatment to remove it. Depending on the wheel and the amount of buildup, removal may not be possible without completely refinishing the wheel. Modern wheel cleaners applied in the wash are designed to release “fresh” brake dust only; caked dust will require detailing or refinishing to restore their “new” appearance.
Why do tires fade and become discolored?
Like the wheels, your tires have several formidable enemies, including water, formaldehyde, petroleum distillates, ultraviolet (UV) light and ozone. Water washes away the natural oils and waxes in rubber that keep it elastic. Formaldehyde and petroleum distillates act as solvents, eating rubber on contact. When ozone is combined with UV light, a reaction occurs that attacks the tire and its polymers.
To protect against ozone and UV damage, a stabilizer molecule called a competitive absorber is blended with the tire polymer. Competitive absorbers work by capturing and absorbing UV radiation and converting it to heat, which is dissipated harmlessly. All tire manufacturers use the same competitive absorber, called carbon black. This is why most tires are black. These absorbers are sacrificial; they expend themselves in performing their function of converting UV light to heat. However, as carbon black loses its ability to perform, it turns gray. This is one reason tires tend to discolor with age.
To protect tires from further ozone damage, tire manufacturers add a compound to their formulas. Tires flex when they are in motion, causing the wax molecules to migrate to the surface. This forms a protective barrier between the air (ozone and oxygen) and the tire polymer. In the tire trade this is called blooming. When tires are parked for extended periods, blooming does not occur, and ozone quickly attacks the tire polymer. With UV light and ozone working in concert, the degradation is accelerated, resulting in drying, discoloration and cracking.
How can I keep my tires looking “factory fresh”?
To combat the negative effects of water, solvents and UV light on tires, the car care industry makes tire dressings. Tire dressings fall into two groups: oil-based and water-based silicones.
1) Oil-based silicone dressings are nonpenetrating coatings that seal rubber and vinyl. They are very good at providing a protective surface barrier. Oil-based silicone dressings create a glossy film that never really dries. I'm not a fan of these products, as most contain petroleum distillates as a cleaning agent. Petroleum distillates are harmful to rubber and vinyl, and will cause cracking.
2) Water-based dressings do not contain oils or petroleum distillates that can harm and dull the surface of rubber and vinyl over time. Most water-based dressings offer a nongreasy, more natural looking satin finish; however, they are not as durable as the oil-based products.
A Final Note
My staff and I would be happy to answer your questions and—based on your description of your vehicle and the work needed—provide you a cost estimate over the telephone. To reach us, call (636) 928-3866. Or stop by Caribbean Express. Our quotes, information and advice are always available without pressure or obligation of any kind.
Thanks again for reviewing my "Consumer Guide to Wheel & Tire Care." I hope you found this information helpful. If you have any questions or comments – or if you’d like to see what professional detailing can do for your vehicle, please stop by the store. You'll find Caribbean Express at 1525 Jungermann Road, a ¼ mile north of Hwy 94 and across from Schnucks in Saint Peters. I’ve dedicated my business to consumer education and service. I’ll be pleased to help you in every way. I look forward to your call. Thanks!
Jeff Pawlik, Owner
Caribbean Express Car Wash & Spa