Chrome is a popular choice for vehicle trim pieces or wheels. Everyone loves the look of shiny chrome rims, especially on vintage muscle cars. Sadly, once chrome starts pitting, it loses its shine in a hurry.
Pitting is one of the major downsides of chrome. Repairing pitted chrome may be possible depending on how severe the damage is. If you’ve caught pitting early, you may be able to reverse it entirely.
The longer pitting is ignored, the less likely it becomes that you’ll be able to fix it. If the chrome plating flakes away, the metal underneath will be left to rust.
What Is Chrome Plating?
Chrome plating is an alloy of chromium and other metals. Chromium is described as a “lustrous, brittle, and hard metal.” For this reason, metal pieces prone to tarnish (like trim and wheels) are given a layer of chrome plating. This creates a layer of corrosion resistance.
Most chrome plating is fractions of a millimeter thin. Contrary to popular belief, thicker chrome plating will not help with pitting. It’s actually been found that thicker chrome plating only emphasizes surface abnormalities.
What About Rechroming?
Chromium is a strange metal. Though it’s usually benign and safe to handle, it can become unstable and change states. As such, there are a lot of regulations that impact the cost of rechroming.
Rechroming at home can have major environmental impacts as well since chromium can be a carcinogen. If you have original, high-quality wheels, then professional rechroming may be worthwhile. Otherwise, new wheels are probably a better option.
What Is Pitting?
Pitting appears as tiny dimples in the metal’s surface. Frequently, these spots appear to be a dark, less shiny gray or even black. If left alone, they’ll eventually expand and lead to rust. In some instances, the chrome looks bubbled. The first sign of pitting is the loss of shine.
Severe pitting occurs when there are significant flakes missing. It can be difficult to restore chrome in this state.
What Causes Pitting?
When exposed to oxygen, chromium becomes unstable. A layer of oxidation forms almost immediately. This oxidation is what causes chrome to take on a dull and pitted finish.
To prevent this oxidation, manufacturers apply a clear-coat to the chrome plating. This works well until an errant rock or curb scratches the clear coat. Brake dust can also break down this clear coat over time. This is why chrome wheels are especially vulnerable to pitting.
How to Clean Pitted Chrome
The first step to repair pitted chrome is cleaning the surface. This is important, because as you work to fix the pitting you may scratch the rest of the chrome. If there is dirt or debris that causes a chemical reaction, you may make the pitting worse than it already is.
To clean chrome rims that are pitted, you shouldn’t need to remove them from your vehicle. Many people do though, and that is a way to make sure they’re clean from every angle.
- Microfiber Cloths
- Warm Water
- Dish Detergent
- Sandpaper or Steel Wool
- Clear Coating
Step One: Clean Chrome Surface
Use a microfiber or soft cotton cloth, dish soap, and warm water to clean the chrome’s surface.
Though vinegar is a great cleaning tool, it is not recommended for cleaning chrome. Vinegar is acidic, which can make the issue worse. If you need to use a harsher acidic cleanser, follow with a total rinse and use a cloth to wipe away any residue.
Use tight, circular motions to clean the chrome’s surface.
Step Two: Polish the Chrome
Once the surface is clean, run a fingernail along the worst of the pitting. If it is significant enough to “catch” your fingernail, you’ll want to start with 800-grit sandpaper. If it doesn’t, then you should use 0000 fine steel wool.
Whether you’re using steel wool or sandpaper, you should select one that will work while wet. Keep it wet throughout this process to minimize visible lines.
In a gentle, circular motion, use the sandpaper or steel wool on the pitting. When you can no longer see the pitting, wash the surface again.
If your pitting was severe enough to start with sandpaper, your second round of polishing should be with steel wool.
If you’re dealing with exceptionally light pitting or looking to build your chrome’s shine, aluminum foil works as an abrasive as well.
Follow these steps until all the pitting is gone.
Step Three: Reapply Clear Coat
The most important step, and the one most often forgotten, is reapplying a clear coat. The pitting started because the clear coat was scratched. By removing the pitting, you have almost certainly removed the remaining clear coat.
If you leave it as is, you’re going to have a lot of pitting on your hands in no time. Apply the clear coat carefully and follow all instructions.
How to Prevent Chrome Pitting
Once you’ve removed all the existing pitting, you should work hard to prevent it from occurring again. One of the easiest ways to do this is keeping your chrome pieces clean.
Clean Chrome Regularly
Salt, brake dust, and even rainwater can all eat away at your clear coat and expose the chrome underneath. Regularly washing with a wheel-specific cleanser can help protect your chrome. Avoid harsh cleaning agents as they can strip a vehicle’s protective coatings.
Polish Chrome Rims & Trim
Regularly polishing your chrome with aluminum foil or metal polish is another way of maintaining chrome. Though this isn’t something you need to do every time you wash your car, it’s good to do it after exposing it to any corrosive elements.
Apply UV & Rust Protectant
Finally, a good UV protectant is inexpensive and easy to use. This will help keep the sun from breaking down your clear coating. Rust prevention agents are also available for an extra layer of protection.
Keep Your Chrome Shining
Chrome’s biggest appeal is its shine, and pitting can take that away quickly. With a little work, you can bring back that shine in an afternoon. With maintenance, your vehicle can look great for years to come.
Chrome may require more work than some other automotive finishes, but there’s no denying its classic appeal.