How to Care for Your Painted Wheels

BMW Painted Wheel
This BMW wheel is painted a standard flat silver color. Rim And Wheel Works, Inc.

Whether they are black, silver, or another color, most alloy wheels are painted, a finish that consists first of a primer sprayed onto prepared bare metal, followed by an automotive-style paint and a protective clear coat that seals the wheel and finish against water and air that can cause corrosion.

Style and Color Options

Not so long ago, painted wheels came mostly in shades of silver, with an occasional set of white, black, or red spotted on the showroom floor. Now there are many new types and colors of paint, from anthracite and gun-metal gray to flat black and bright white. Some owners like to have their wheels painted the exact same color as their car, while others like a contrast between the two, which can be used to enhance the overall look of the vehicle. Using a slightly different silver from a silver car body, for example, makes a subtle but definite statement. Some wheels are given the "full-face paint" treatment, in which the entire wheel is painted. Other owners opt to get what's known as a "flange cut," in which the outer edge of the wheel is left machined.

How Wheels Are Painted

Newly machined alloy wheels are painted much in the same way the body of a car is painted. First, primer is applied, then the paint, using a high-velocity, low-pressure (HVLP) spray gun. Once the paint dries, the wheels are sprayed with either a liquid clear coat or a powder coat, which is baked onto the wheel for a finish that is tougher than the original alloy.

Refinishing Damaged Wheels

One of the ways in which you can damage the finish of your vehicle's wheels is to brush up against a curb or other road hazard, a condition known as "curb rash." This will inevitably scrap the finish off the outer edge of the wheel and also damage the underlying metal. Other types of damage include scrapes across the spokes and damage from improper use of mounting machines or torque wrenches. Unfortunately, there is virtually no way to touch up such damage. To simply touch up a single damaged area will leave a discontinuity between the different applications of clear coat, which will eventually allow corrosion to affect the metal. In addition, aluminum alloy that has been exposed to air begins to corrode almost immediately. Even this microscopic layer of corrosion is enough to prevent an attempt at a touch-up from sticking correctly.

To properly refinish a wheel, it must be bead-blasted back down to the bare metal. It is then usually run on a CNC (computer numeric control) lathe to smooth out any damage to the metal itself. Deep scratches can be fixed by welding and then lathed down to create a smooth finish that is flush with the rest of the wheel. The wheel must then immediately be primed to prevent the corrosion layer from forming. Priming, painting, and clear-coating must all take place in a substantially dust-free environment, or the resulting finish will be speckled with dust particles.

The process is not cheap. Refinishing generally costs somewhere in the $200 per wheel range, although the very high cost of original equipment wheels ($500–$600 new) means that you might just be better off buying new wheels.

Taking Care of Your Painted Wheels

Any clear-coated wheel should be cleaned with a product that is non-acidic and non-abrasive. Unfortunately, many commercial products sold as wheel cleaners so not meet this criteria. Any product that says to spray on and remove within 2–5 minutes is probably a low-acid solution, which will burn off brake dust very quickly but also eat away at the clear coat. It doesn’t take very long at all for such cleaners to get under the clear coat and begin to kill the finish, as well as allowing environmental conditions to corrode the wheel. Acid damage will, therefore, show up very quickly on painted wheels, looking like white spiderwebs beneath the clear coat. Even some full-service carwashes will use acid-based cleaners to clean wheels as quickly as possible, so do your research and only go with reputable car washes.

If you want to do it yourself, P21S, Simple Green, and Wheel Wax can all be used safely. Wheel Wax, designed for application on clean wheels, also works to prevent brake dust from sticking to the wheels in the first place, and making particles that do stick easier to remove.