What are Diamond Cut Alloy Wheels and how to Repair them
These days, nearly all new cars are supplied with Diamond cut alloy wheels. Gone are the days of plastic wheel trims secured to old steel wheels with a cable tie. Modern alloy wheels generally improve the appearance of the vehicle and are also lighter, improving fuel economy.
What are Diamond Cut Alloy Wheels?
Alloy wheels would be formed or ‘cast’ into the desired shape and then painted, usually, silver before a clear protective lacquer is applied to produce a smooth gloss finish. However, in recent years, an additional step has been introduced to the manufacturing process. After the paint is applied, the face of the alloy wheel is finely cut on a lathe producing a finish comparable to the surface of a CD or DVD. The finished wheel is then lacquered to protect the surface. The end result is known as a Diamond Cut Alloy Wheel. Why ‘Diamond Cut’? Because the cutting tool inside the lathe has a diamond tip.
This new finish to the alloy wheels presents a new challenge when it comes to repairing damage. As you might expect, the ingenuity of the modern alloy wheel repair technician has developed a number of different methods to fix a damaged diamond cut alloy wheel should a kerb have made an unwelcome approach. Our SMARTvan Diamond van builds are fitted with a full CNC lathe for repairing damaged Diamond Cut Alloy wheels back to OEM finish.
How to repair Diamond Cut Alloy Wheels?
There are 3 types of repair methods for Diamond Cut Alloy Wheels generally offered:
1) Paint - The wheel can be painted to either match the original finish as close as possible or an entirely new colour of the customers choosing. The SMARTbooth is ideal for alloy wheel repairs or the refinishing of any small items & components.
2) Polish - Using a variety of different grades of abrasive and polishing compounds, the surface is polished to closely resemble the ‘shine’ of the original diamond cut finish.
3) Re-Cut - Practically identical to the original finish, the wheel face is cut on a CNC lathe which removes the damage and replicates the same reflective ‘DVD’ appearance.
Here’s a closer look at the 3 methods in a little more detail:
1. How to refurbish by painting
This VW alloy was originally painted black with a diamond cut face. The damage was repaired and then the black sections were masked off – a process that takes both patience and skill. The face of the spokes are then painted in a very fine silver to match the original finish as closely as possible. The masking is removed and a protective gloss clearcoat is applied.
Another option here would be to paint the entire wheel silver, black or a colour of the customer’s choice. This would avoid the need for the masking process but the end result would be a single colour rather than the two tone effect. These wheels were repaired by our customer Josh Tebay from AutoSmart in his SMARTvan:
2. How to refurbish by polishing
This can be the quickest repair method (depending on the extent of the damage) for diamond cut alloy wheels but does leave a visible indication that a repair has been completed.
Once the damage has been removed from the wheel with a suitable sander and abrasive, the affected areas are gradually brought to a polished finish by using a series of increasingly finer abrasives. To the untrained eye, when the repair is complete and fitted back to the car, it can be difficult to spot. What will often be left is the ‘edge’ of the original clearcoat where the repair process was stopped. This method could also be considered the least durable of the 3 methods as there can often be very little ‘grip’ for the new lacquer to adhere to on the freshly polished surface.
The BMW wheel in the images below has been repaired using the polish method. The yellow circles highlight the areas where the repair stopped showing the ‘edge’ of the original clearcoat that is referred to above. Here are some more wheels repaired by our customer Josh Tebay from AutoSmart in his SMARTvan:
3. How to refurbish by re-cutting
This method requires a CNC lathe – a computer-controlled lathe that will read the face of the alloy wheel and then cut back to the original finish. These machines are not cheap (circa. £30k) but are necessary if the wheels are going to be repaired back to as close to the original condition as possible.
It is also possible to ‘upgrade’ many standard painted wheels to a diamond cut finish using these machines providing an additional revenue source to service providers. The standard silver Toyota wheels in the images below were painted black and then cut on a mobile CNC lathe. The result is a very different looking wheel which can transform the overall appearance of the car; useful if you like customising your vehicles or if you want your car to stand out from the crowd when trying to sell it. These wheels were repaired during training in our SMARTvan Diamond:
Get in touch with our alloy wheel repair experts
At SMARTFIX we can provide workshop and mobile equipment to complete all the repair methods covered here. Get in touch with our alloy wheel repair specialists today to find out more about how we can help your business.