How to Fix Gutter Rash on Alloy Wheel Rims | LK Performance
Posted on: 14/10/2014Gutter rash, also known as ‘curbing’, is a terrible blight of modern day living, as anyone with a set of shiny new alloy wheel rims will attest.
Touching the curb, either by misjudging a corner or scraping during parking causes the most unsightly damage to alloy wheels, as the granite comes into contact with soft, shiny metal. It can manifest as a dent in the outer wheel rim, scratching and scuffing of the wheel surface, or in extreme cases, it can damage the seal enough to allow the tyre to leak air.
It’s entirely possible to go to a shop and get the rims seen to though. There, they mount them on a lathe and take a thin layer of metal off, leaving a smooth, immaculate finish, which is then re-sprayed or lacquered.
If you’d rather do it yourself, you’ll need to take the wheels off the car and the tyres off the wheel, so it’s a bit of a job, needing a well-equipped, well-ventilated workshop and either another means of transport, or another set of wheels for a couple of weeks whilst you sort out the rash. Put it this way: it’s not a process that can, or should, be rushed.
Think you’re up to the task? Here’s our 14-Step process for taking care of your gutter rash.
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Step One
Take off any lead balancing weights. You’re going to need to get the wheels rebalanced before you put them back on the car. Clean the wheel thoroughly.
Step Two
For serious rash, you will need to get rid of the worst of it with a file. Don’t try and completely remove the curbing, or you might alter the wheel’s shape. You just need to remove anything standing proud of the surface.
Step Three
Roughen the entire surface of the alloy. You want to achieve a matte finish using a 600 grit sandpaper, and clean as you go with copious quantities of water and detergent. If there’s any corrosion, take it down to the bare metal. Give special attention to the wheel rim as this is where most of the damage is likely to be, but it can easily get overlooked.
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Step Four
Ensure the wheel is perfectly clean and completely dry, including any dings or dents, to ensure that the filler properly adheres. P38 body filler, or ‘chemical metal’, is ideal for this job. Follow the manufacturer’s instructions, but allow at least 24 hours before the next session of sanding.
Step Five
Again using plenty of water, smooth down the filler using 400 grit sandpaper. The plan here is to create a uniform wheel shape, on the flats as much as the rim, so don’t get carried away. If you do, no biggie, just return to the previous step and add more filler.
Step Six
Spray-filling will plug any fine holes, either in the wheel or the filler itself. It might seem like a fuss, but it’s really worth doing as it produces a flawless, even finish that’s great for spray-painting.
Ensuring the wheel is clean and dry, and following the instructions on the can, apply three even coats of spray filler. Leave around 15 minutes between coats. To prevent the filler hardening in the kit, soak the nozzle in thinner between coats to be sure your last coat is as good as the first.
Once you have put on the final coat, have a quick check for any remaining defects. If relatively insignificant, they may well sand out, but allow at least 24 hours to dry before going back to sanding to allow the filler to harden properly.