Diamond-cut vs painted alloys: what's the difference?
If you've been quoted wildly different prices to fix the same-looking damage, this is usually why. Not all alloys are finished the same way, and the finish decides how the repair is done.
Painted alloys
The most common by far — silver, gunmetal, gloss or satin black. A colour coat over primer, sealed with clear. These are the straightforward ones: damage gets filled, sanded, colour matched and resprayed in 2K on the spot. Done in your driveway, same day, and once it's cured you genuinely can't pick where the damage was.
Diamond-cut / machined face
These have a bright, almost mirror-fine finish on the face — cut on a lathe so the bare aluminium shows through, then lacquered over the top. You'll see fine concentric lines if you look closely. The lathe cut is the reason they look so sharp, and also the reason they're harder to fix: matching a machined face properly means re-cutting it on a CNC lathe, which is a workshop job, not a driveway one.
What that means for your quote
If your wheels are painted, expect a straightforward mobile repair from $120 a wheel. If they're diamond-cut, the honest options are a workshop re-cut, or converting the wheel to a full painted finish — which I can do at your place, and which a lot of people actually prefer because it's more durable and won't lacquer-peel the way diamond-cut does.
Which lasts longer
Painted, comfortably. Diamond-cut looks fantastic new, but the clear over bare aluminium is prone to lifting once moisture gets under it — that milky, blotchy corrosion creeping in from the lip is the classic sign. A properly prepped 2K painted finish doesn't do that, which is why I back mine with a 12-month written finish guarantee.
Common questions
How do I know if my wheels are diamond-cut?
Look at the face in good light. Diamond-cut wheels have very fine concentric machining lines and a bright metallic sheen, usually with the spoke recesses painted a darker colour.
Can diamond-cut wheels be repaired at my house?
Not to a true diamond-cut finish — that needs a CNC lathe. They can be converted to a durable painted finish at your driveway, which many owners prefer.
Is a painted finish worse than diamond-cut?
No — it's usually more durable. Diamond-cut lacquer is prone to lifting and corroding from the lip inwards.
Related: what alloy wheel repair costs · repair or replace? · mobile rim & wheel repair · areas I cover