Even those with the most meticulous car cleaning habits, it’s still natural for aluminum rims to oxidize over time. The process simply comes with the material.
Yet, all is not lost - we’ll help you quickly learn how to remove oxidation from aluminum rims to give them new life and have them looking like the first day you purchased them.
Using just a few materials and tools, you can clean your wheels quickly for a fresh shine and uncompromised performance. In this article we’ll go over how to clean your wheels, remove the oxidation, and prevent future oxidation buildup.
What Is Oxidation?
Firstly, corrosion is not the same thing as oxidation; it is a result of it. Oxidation happens when a metal is exposed to an oxidizing agent, such as air. When this happens, particularly to aluminum, the metal forms a thin, hard film of what is known as aluminum oxide.
This film is the metal’s way of resisting corrosion. Corrosion doesn’t happen until this hardened film dissolves away, but aluminum is very corrosion-resistant, so there’s plenty of time before this happens.
In short, oxidation is a form of self-healing and protection that aluminum metal exerts. While it’s good that it protects itself from corrosion, it is a sign that corrosion could occur soon. Plus, it doesn’t look too great on your wheels.
Aluminum oxidation can happen pretty quickly - faster than steel oxidation. Aluminum atoms tend to bond strongly with oxygen, which leads to the hard, white-colored surface on your rims.
In case you were wondering, aluminum does not rust. Only ferrous metals can rust, though you can get after-rust on your aluminum if ferrous metals scratch or become embedded in your aluminum.
Steps to Remove Oxidation & Restore Wheels
Removing oxidation from your rims is actually quite simple and doesn’t take very long. The key is to clean the rims, expose the oxidation layer, and the rest just takes a little bit of elbow grease from you.
1 - Check for a Coating
This first step is quick, but important. Some aluminum wheels have a clear coat over the aluminum, which is there to protect the metal and prevent oxidation. You’ll need to determine if you have a coating or not.
With a clean microfiber cloth, apply a small amount of polish on a small area that is out of sight. When you wipe off the polish, oxidized aluminum will leave black residue on the rag meaning you have bare aluminum. If there isn’t black residue then you have a coating.
If you have a coating, you may just have dirty rims and not oxidation. Follow the cleaning steps below. If it appears you still have oxidation and the coating is in bad shape after cleaning, you may need to remove the coating with paint thinner before moving onto step 3.
2 - Clean the Wheels
Assuming you don’t want to remove your wheels to do the work, park your car in a shady location away from dirt or grime. You can work in the sun, but doing so may cause your cleaning supplies to dry up faster. Removing the wheels is going to make the work easier, but that would require lifting your car and removing all of the wheels or doing them two at a time.
Start by removing loose debris, dust, dirt, and grime - basically, anything you can get off without water and detergent. Your wheels will likely have brake dust, grime from the road, and dirt caked on that should be removed first. A stainless steel wire brush can help with some stubborn gunk.
Using a hose with a nozzle, wash off the wheels with water. Work slowly, cleaning one wheel at a time to remove any loose buildup along the way. Be sure to spray between the spokes, around the brake calipers, and behind the wheel.
If you have access to a power washer, this will be the most effective way to complete this step. If not, you can use a standard hose with an adjustable nozzle.
Once the larger debris and grime is gone, follow this up by scrubbing the rims with water and car wash detergent to clean them as much as possible.
An optional step, but recommended, is to use an aluminum wheel cleaner to give it a deeper clean. The directions are different depending on the brand you choose, so please read and follow the specific instructions on the label.
*At this point, if you have a coating on your rims and are still showing signs of oxidation, you can either use a paint thinner to remove it, or jump right into the sanding.
3 - Sand the Rims
Starting with a 400 grit wet/dry sandpaper, sand down the rims to remove any pitting, scratches, and curb rash. If you have deeper pitting or scratches, you may need to start with a more aggressive sandpaper like a 240 or 320 grit.
You will usually get the best results from hand sanding, but if you want to spare some energy and have rims that aren't hard to access with an orbital sander or angle grinder, you can try a sand paper disc to get most of the work done.
Continue sanding until all of the pitting and scratches are gone. Switch to fine-grit sandpaper and smooth out the surface, working your way up to 800 or 1,000 grit to remove any grooves or roughness. Use a clean, dry microfiber cloth to wipe away any dust from sanding.
4 - Rinse & Dry
Use your hose again to rinse the wheels, tires, and wheel wells of all soap and cleanser. Thoroughly clean these areas, and be sure to get in between lug nuts and spokes.
Use a clean, dry microfiber cloth to dry your rims. You shouldn’t let them air dry, as this can cause spots.
5 - Polish
Use your favorite compound to polish your now-clean and oxidation-free wheels. Apply the polish using either a clean/dry microfiber cloth, felt polishing disc, or a ball-shaped power polisher. Make sure you get the whole wheel before wiping it down with a fresh cloth to finish.
How To Prevent Aluminum Rims from Oxidizing
Aluminum has a pretty tight relationship with oxygen, so there’s not too much you can do to prevent oxidation from happening. However, ignoring oxidation can lead to corrosion, which is very serious and something you want to avoid.
A protective coating and regularly cleaning your rims will be the best way to prevent future aluminum oxidation.
You can apply a few different kinds of protective coatings to your aluminum rims to help prevent corrosion. The most common ones are:
- Powder coats
- Paint (Clear coat or colored)
Paint and powder coatings have more options in terms of protection with higher electrical resistance. These options are great for preventing galvanic corrosion.
Anodes are known as sacrificial anode coatings because they erode much faster than aluminum. Essentially, you use these coatings and let them take the heat of the oxygen and corrosion instead of your rims.
Unfortunately, you have to replace an anode more frequently than paint or powder, but it tends to look a lot nicer.
A wax coating is a cheap and easy option, but not the best choice. It can wear away while driving and needs to be reapplied every 3rd or 4th time you wash your rims.