As enthusiasts, we all have excellent car control. Whether parking parallel, at an angle, or straight in, we never hit anything, and our wheels remain pristine forever. Some people aren’t as perfect as us, though, and they ding up their wheels and scrape them on curbs, leading to the dreaded curb rash. It’s an unsightly thing, but thankfully, something can be done about it.
Wisely Automotive took to YouTube to show us the process for repairing an alloy wheel that has suffered this kind of damage. They walk through each step from start to finish as they run a full restoration job on the diamond-cut wheels from a BMW i3.
The action takes place at Alloy Fix, a wheel repair service in Dartford, England. It’s a simple enough job, as it turns out, but one that takes experience and attention to detail to get the best results.
Bring ‘Em Back
As Umar from Alloy Fix explains, the first thing to tackle is the basic prep work. The tires need to come off the wheels, as do the TPMS sensors, center caps, and wheel weights. From there, each wheel is dunked in a plastic bin full of stripper to remove all the original paint. They’re then sandblasted to further remove anything remaining on the bare metal and etch the surface for powder coating.
After all this, the wheels look deliciously clean. Removing the paint and sandblasting the wheels has removed the ugly curb rash. However, more serious work is required before the wheels are ready to be refinished.
Depending on how hard you hit a curb, you might find that you not only chewed up the edge of the rim but buckled it, too. At this stage, the wheels are put on a jig that spins them up and checks for roundness and flat spots.
To fix any buckles, a torch is used to heat the wheel before it’s pushed, pulled, and manipulated back into the correct shape with hand tools and hydraulics. A lathe is also used where necessary to remove material and create the best possible bead for the tire to mount upon.
From here, the wheel is ready for powder coating. The rims are first placed in a heating chamber at around 400 F for twenty minutes to degas them and remove any moisture. “We degas the wheel because obviously metal is porous,” explains Umar. “Within its structure, it’s holding moisture and gases that we’re trying to get rid of.” Preheating the wheels is thus critical to ensure the finish sticks properly.” By heating this wheel up to 200 degrees [C] … the air, the moisture, anything else that’s trapped in the structure will come out,” says Umar. “Then, when we powder coat it, we won’t get any bubbles or any imperfections within the surface of the powder coating.”
The wheel is then placed on a frame for coating, and hooked up with a grounding cable. As the coating is sprayed on, the powder-coating gun gives the powder particles a negative charge. Since the wheel is grounded, it attracts the powder particles via electrostatic forces. “When the powder comes out the gun, it gets sucked onto the wheel,” explains Umar. The coating is then baked in an oven to harden, before being allowed to cool.
[Ed note: I couldn’t resist adding the video below, which shows powder in action including a time-lapse of the powder liquifying and hardening, which is downright magical. The video will go right to the powder part of the show when you click – Pete]
In the case of the i3 wheels, they’re given a black finish all over. To recreate the original look, the spokes on the face of the wheel are then “diamond cut” to create the silver contrast effect. The wheels are placed in a computer-controlled lathe which removes a small amount of material from the wheel to create the desired finish. “As you can see … we are removing metal,” explains Umar. “That means that wheels can only be cut a certain amount of times.”
Final touches include another trip back to the degassing oven and a coat of clear over the top. This gives the wheel a rich deep shine, both in the powder coat and on the bare diamond cut areas. From there, the wheels can be refitted with tires and TPMS sensors, rebalanced, and put back on the car.
The Quick Way
You probably watched that and thought “damn, that’s a whole lot of work.” That’s true. That’s partly because the wheels in question were fancy diamond-cut BMW items. It’s also because the gang at Alloy Fix takes an all-encompassing approach to wheel restoration.
If you’re short on time and money, you can cut a few corners here and there. As demonstrated by ChrisFix on YouTube, it doesn’t have to be so hard. If you’ve got simpler wheels with bad curb rash, you can get them looking good again with a lot less equipment and a lot less work. Doing it this way won’t fix any buckles or more serious damage, but it can make a huge visual impact on your ride.
The video concerns the restoration of Cadillac rims with deep scratches from curb rash. ChrisFix uses a pretty simple process to repair the damage. He starts by cleaning up the rim with soapy water. From there, he uses a rotary tool with a 120-grit flap disc to sand out the deep scratches. He then uses chemical stripper to remove any clear coat from the wheel. The whole wheel is then fully wet-sanded to create a smooth, attractive surface. Finally, he applies fresh clearcoat and calls the job done.
ChrisFix doesn’t worry about things like stripping the tires off or rebalancing the wheels. Ideally, you won’t have to remove enough material for that to be a problem. It’s not a great fix, but it does make the wheels look ten times better for a few hours work and less than $200 in tools and materials.
The path you choose comes down to your budget, your taste, and your wheels. If you’ve got badly buckled wheels, diamond-cut wheels, or you just want the absolute best, it makes sense to get the job done professionally. After all, few of us have wheel lathes or powder-coating ovens at home. If, on the other hand, you’ve got a kinda-nice hooptie with some scuffed-up rims, it might pay to bust out the Dremel and sort the problem out yourself. You may argue about the proper way to do this in the comments.
Image credits: Wisely Automotive via YouTube screenshot, ChrisFix via YouTube screenshot
I’m a bit surprised to not see any sort of hardness control for the wheel itself. I guess the torch at least anneals it some as they’re bending it back into place, but wouldn’t it be weaker afterwards?
Had a small dent in one of the Z06 replica wheels on my used 2011 Corvette. Was able to buy a new matching wheel for under $100. Can’t imagine any of these processes are less than $100. I did keep the dented one as a spare in case these wheels are no longer available in the future should I need one though.
From the article, “As the coating is sprayed on, the powder-coating gun gives the powder particles a negative charge.” The gun gives the powder a positive charge. The object being coated is grounded to earth via a ground wire/strap. Positive to negative.
Mind where you use and get that stripper. I don’t know what it does to vulcanized rubber but it destroys nitrile and any plastic I’ve ever touched it with in no time at all.
One should always mind whwre to use and get that stripper
Truer words were never spoken… you can get all kinds of unwanted rash from improper use of that stripper.
The Big Sidewall Squad with their signature look of superiority.
But for real nice read! Those I3 wheels look pretty nice bare metal
That time lapse video is magical. It looks like the effect if someone in a movie waved a magic wand and changed the paint somehow.
The article is good, too. The DIY method certainly looks better to me than the plasti-dip solution I’ve seen from people (though that probably protects from future curbs more).
Don’t tell, but I curbed all four wheels on my GTI over a four year period. I had my wheels restored recently and the results are fantastic (and so much cheaper than buying new wheels). It was very affordable — I paid C$100 per wheel. I also took the opportunity to put some new, better tires on my car, so win-win.
I had this done to the 20 year old Panasports on my Miata. I got to pick the finish color and they came back straight, balanced, and looking brand new.
Thank you for showing me the proper way to administer a rim job. Apparently I’ve been doing it wrong this entire time. Maybe that’s why I don’t get too many second dates.
That’s a very aggressive technique to explore on a first date. I applaud your willingness to explore the road less traveled.
Listen, I’m a renaissance man. I’ll do what’s necessary to get the job done. If that job requires repairing a potential mate’s rims properly, then that’s what I’ll do.
Too many half-ass motherfuckers out in the world.
Also, kudos to you on the road less traveled entendre. I always appreciate a cheeky comment.
First an article about the Austin Swallow, and now how to do a proper Rim Job.
Let’s see… I pay a subscription. There are Categories of content, most of it pretty esoteric, if not outright fetishist. Every post plays a video, whether I want to see that or not…
Damn, site should be named Autopianhub. Ya know, ‘Cause wheels, right?
Autopunhub? These puns just write themselves.
Yours is better.
This site is filled with “Auto”erotic pun-ography.
Or if the site decided to have a section dedicated to Dr. Octopus, it could be Otto-erotic pun-ography.
(my head hurts now)
I had a guy in LA come to do some mobile bumper dent/paint repairs – he threw in a curb rash cure on one of my wheels for an extra $75.
I’m overdue to get that work done again – on both bumpers and all 4 wheels.
Chemically stripped the peeling clear coat off the phone dials on the ’88 Regal I had in college. Polished the the aluminum with drill and Dremel flap wheels. Then immediately got new tires mounted (the old ones were trash anyway). It was a LOT of work for a satisfactory end result.
Yeah, every time I’ve looked into having a wheel repaired, it always has been cheaper to just buy a new wheel. Sure, I’m not rocking some expensive HRE’s or anything like that, but yeah, not worth it.
Bent a wheel on my 2010 Acura TSX. Was WAY cheaper just to buy one.
same, needed 2 wheels repaired on my XF, the repair quote was like 800 dollars. I found 2 in nearly perfect condition from a salvage yard in Georgia – cost 160 per wheel.
I had this done to one of the wheels of our mk3 tts, and it’s a trade I really appreciate paying for. Saved me a a lot of cash after letting the wheel fall on its face in my garage. Also, to the asshole engineer who designed a wheel with a protruding rim face you owe me money! I’ve even saved money having second hand OEM wheels refurbished over buying new.
We’ve got rim rashes AND swallows today, it’s gonna be a good one.
And we haven’t even gotten to TMD yet, what a Thursday!
Don’t forget to lube your joints and top your fluids!