The Front n/s alloy has gone dark in patches and will not clean properly.

I was having the car cleaned and this was brought to  my notice by the valet.

Other 3 wheels are ok and clean well.

The valet thought it could be rust as it is rough to the touch. Has anyone got any Ideas what it might be.

Thanks 

Maybe rust, maybe rust from brake discs, maybe baked on brake pad dust etc etc

Have you had the car from new and know it is the original wheel, not refurbished or replaced?

 

If the valeter never knew what it was and could not remove fall out it is difficult to guess without a picture or 3.

Er, steel and cast iron are alloys.

 

Presuming you mean "aluminium alloy", aluminium corrosion products are white rather than rust coloured.

Possibly mix of brake block dust, brake disc rust and aluminium oxide

 

Of course aluminium doesn't rust, it just corrodes and forms oxide on its surface which is very hard

 

(rust only happens to iron based metals, and is larger than the metal it came from, which is why it forms bubbles and flakes)

 

The rust off rusted discs and sintered pads forms rust.

 

Alloy wheels are lacquered even Diamond Cut stylee ones. Not bare alloy. The fallout bites in.

Then there is Alloys that have been damaged repaired.

Edited 15 August, 20196 yr by Roottootemoot

Thank you for the quick 

I have taken some photos which might help to identify what the problem is

Ah, that's general speckling. The most likely cause is the powder coat failing.

Baked on brake dust and iron filings. Gone too long.  How does a valleter not know that?

 

 

 

Thank you to all who read and replied to my post. I have read them all and settled on baked on brake dust. I purchased an oddly named product from WILCO car accessories shop ; 

Dodo Juice Ferrous Dueller Wheel Cleaner Spray 500ml

I tried it to day on a small area that was really thick...................... and it works.

So once again the forum does give great advice........Thanks again (Tom)         Enryroomster