Facelifting Alloy Wheels

Maybe your car’s alloy wheels have had a hard life and are covered in nicks, scuffs and scrapes. Or perhaps you don’t like their colour. But either way, it’s straightforward to bring them back to as-new condition in any colour you want.

So what’s the detail?

Repairs

The first step is to have the tyres removed and then inspect the wheels very closely. Big dents or very deep scrapes (especially in the lip of the rim) will need to be professionally repaired. These spots are often built up with weld before being machined in a lathe. (See Damage Control for more on professional wheel repairs.) However, more minor imperfections can be easily repaired at home with just simple tools and a bit of work.

These wheels, while in generally good condition, had...

..some dings around the centre hole and...

..some imperfections on the spokes.

In addition there were stone impact marks sprinkled at random.

Filing and Sanding

The first step was to remove the marks from the spokes. A fine half-round file was used...

...or to speed things up, a sanding disc in an angle grinder can also be used. When using either the grinder or the file, take off only the minimum of material and blend the low spot into the surrounding metal.

In this case, the sanding disc was also used to remove some scratches from the outer edge of the rim. Using the sanding disc without any rubber backing support allows the disc to bend flexibly, making it easier to blend-in the low spots. Always wear safety glasses – unsupported in this way, bits of sanding disc can fly off.

Oh yes, and the valve fitting can now be removed from the inside of the rim, making the next steps a lot easier!

You then need to sand smooth the file marks, starting off with a coarser paper...

...and then when the original scratches can’t be seen, moving to 360 grit wet-and-dry, used wet.

Then go over the whole wheel face with the 360 wet-and-dry, doing the surface of the spokes, their edges, and all visible parts of the rim. As well as preparing the wheel for the colour that will follow, sanding the whole rim will help you find normally hidden imperfections.

Don’t forget the recessed bolt holes.

Once you’ve rubbed the wheel back, give it a good bath, using a plastic kitchen scourer to clean off any sanding residue and dirt that remains. Make sure that you get right into every nook and cranny.

Dry the wheel with a clean cloth....

...and then inspect it for bits that you have missed or imperfections that remain. Here I’ve found a small piece of tar stuck inside a spoke. If you find that any further work is needed, continue with the sanding then when you’ve finished, repeat the clean-then-inspect process.

Colour Change Choices

There are three approaches that you can take to changing (or renewing) the wheel colour:

1. You do the painting - At about AUD$15 per wheel, doing it yourself is not only much cheaper than other approaches but it also gives you complete control over the process, including how long it takes. (Remember, your car will be off the road during the colour change – some professionals talk a two week turnaround.)

Those are the upsides, but the downsides are that unless you have a spray booth, it can be very difficult to exclude dust and dirt and it’s easy for a one-off painter to have problems with crazing, paint bubbling and other similar problems. However, if you do decide to give it a go yourself, you’ll need a spraycan of fill primer, a can of wheel colour and a can of clear. Make sure that you thoroughly clean the wheel with a wax and grease remover before applying the fill primer, and rub back with fine paper (eg 800 or 1200) between coats. Another tip – don’t spray the final clear coat unless the wheel is above 20 degrees C (if it’s colder than that, heat the wheel).

2. Professional Painting – Most crash repair shops can paint your wheels. A tough paint (eg two-pack) is often used. The range of colours is effectively infinite, while cost depends a lot on the amount of preparation needed but starts from about AUD$45 per wheel. If you take this route, deliver the wheels to the paintshop thoroughly rubbed back and smooth – no sanding scratches should be able to be seen. If the ‘shop needs to do more preparation, you’ll be paying for it at professional rates!

3. Powder Coating – as covered at Powder Room, powder coating is a process that applies a super tough plastic coating. When powder coating alloy wheels, the wheels are first sandblasted, which takes the wheel back to bare metal and also leaves a slightly pitted surface that allows the powder coat to ‘key’ into the surface. Acid baths may also be used to clean and etch the surface. Powder coatings are available in a wide range of colours (though unlike paint, not an infinite range) and costs from about AUD$50 per wheel, depending on the complexity of the wheel’s design.

Polishing? You can also elect to have the wheel polished to a shiny aluminium finish. The preparation is much the same as shown here but the costs can be significantly higher, especially on wheels with a complex design.

We initially tried painting these wheels ourselves but couldn’t achieve the professional results we were after. So instead we decided to get the wheels sandblasted (it’s not actually sand, but anyway) and then powder-coated. The whole of the wheel (ie inside and out) is powder coated and so before fitting, a file should be used to scrape away the powdercoat layer around the inner diameter of the centre hole. If you don’t do this, there may be clearance issues between the wheel and the centre spigot of the hub.

The Spare? Don’t forget the spare wheel! If it’s a factory alloy like all the rest, make sure that you facelift it as well – otherwise, if you have a flat tyre, your car will look really strange until you get it fixed... In the case of the car covered here, the spare is a spacesaver - so no work was needed. (It will always look strange with the spare on!)

Centre Badges

In most cases the centre badges are likely to look a bit rough compared with the brand new appearance of the rest of the wheel. The answer is to have new centre badges made, an approach that we’ve covered at Installing New Wheel Badges.  However, the wheels shown in this story required something more. They’re from a Japanese import 1999 Toyota Prius.

Standard, they look like this, with a weird plastic hubcap covering three of the spokes.

With the hubcap off, the underlying alloy wheel was revealed. As you’d expect, there’s no centre cap for the hole in the middle of the wheel. The drama was finding a centre cap on which to mount the badge – even after an extensive search, nothing that we could find fitted.

New 45mm diameter centre badges were made by a firm specialising in metal printing. At AUD$6 each, these resin-coated aluminium badges are cheap and look good. Lots of thought was given on how to best hold them in place. The centre cap needs to be removed whenever the wheel is placed on a balancing machine, so gluing the badges into place wasn’t an option. In the end a very simple approach was taken.

These rubber bath plugs were found to be a tight fit in the centre hole.

The centre of each plug was cut out for clearance then...

...they were painted black....

...and inserted into the wheel hole,

...so providing a mounting surface for the badge.

The back of the badge was roughened with sandpaper and then...

...silicone adhesive was applied before...

...the badge was put in place.

The badges look perfect and they can still be removed if required.

Conclusion

Good looking wheels make a radical difference to a car’s appearance. But if you’re happy with the wheel design that you already have, a facelift can give the improved appearance at a cost much less than buying new wheels.

Overall Cost? While taking the approach shown in this article is much cheaper than buying new wheels, the costs can still add up. In addition to the cost of sandblasting and powder coating (AUD$50 a wheel), there was also the cost of having the tyres removed (we got it cheaply at AUD$2.50 a wheel), having the tyres refitted and balanced (AUD$15 a wheel) and then in our case, sourcing new Toyota-specific factory wheel nuts (incredibly, AUD$10 each nut). The badges cost AUD$6 each and the bathplugs a few dollars. So in this case, the cost of the facelift was over AUD$100 per wheel.

Melting? In a motorsport application we suggest removing the pwodercoating from the hub mounting face - it may soften if wheel temps rise a lot under heavy braking.

Light Wheels? One good reason for doing a facelift of the original wheels - rather than sourcing new alloys - is if the originals are very light. At 5kg each, these Toyota wheels weigh very little for 15 x 5 wheels. For example, the 15 x 6 (ie slightly larger) Mazda MX5/Miata factory alloys, known for their lightness, weigh nearly a third more. Light wheels decrease rolling inertia (improving vehicle acceleration) and reduce unsprung mass (improving ride and handling). So given that these wheels are low in mass, fit the car perfectly and have OE build quality, in this case the decision was made to upgrade the appearance of the wheels rather than swap them for new ones.