1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Is this white worm / corrosion?

Discussion in 'Motors' started by m@rty, Jul 13, 2018.

  1. m@rty

    Wise Guy

    Joined: Jul 5, 2006

    Posts: 1,410

    Location: Glasgow

    Hi Guys,

    I recently bought my first car (2016 VW Scirocco R) about 3 weeks ago which has been great, however I have started to notice some sort of white substance forming on the wheels (19" Cadiz Alloys). This is more noticable on one of the wheels in particular, however there are smaller marks which look similar starting to appear on the others also.

    They don't feel like scratches at all and feel like small bumps forming underneath the top layer of the alloy wheels. After a quick google I think this might be the start of some white worm / corrosion and would appreciate some feedback.

    I was informed that these were new alloys fitted to the car so I wouldn't expect this to happen in such a short period of time.


    Last edited: Jul 13, 2018
  2. shauncr91


    Joined: Dec 28, 2007

    Posts: 11,410

    Location: Sheffield

    My GF's 2016 Abarth 500 has had 3 wheels replaced under warranty so far due to corrosion on the diamond cut. Honestly I'd just suggest having them refurbed in a solid colour to avoid future aggro.
  3. Rotty


    Joined: Oct 18, 2002

    Posts: 39,977

    Location: Notts

    often sign of a bad refurb on diamond cut wheels
  4. theone8181


    Joined: Mar 27, 2013

    Posts: 3,714

    My wife's diamond cut wheels look similar. What happened with hers was moisture gets under the laquer on an edge where it's been cut and starts peeling it away. Hers look appalling.
  5. Finglonga

    Wise Guy

    Joined: Aug 20, 2008

    Posts: 1,713

    Location: Stafford

    Yep, whiteworm and worth a warranty trip to the dealer. I have had 3 of the 4 GTI wheels replaced because of it and they have started going again. They will try to fob you off saying it is stone chips causing it but push them as it is a known problem with their low quality lacquer on diamond cut wheels.
  6. mikeh501

    Wise Guy

    Joined: Jan 18, 2004

    Posts: 1,866

    Location: Somewhere

    the wonder of diamond cut wheels. would never own another car with them.

    it only takes a small chip in the lacquer to let air seep in. air corrodes the exposed aluminium creating the ali oxide you can see. This then keeps progressing underneath the lacquer.

    Warranty repair, or get them fully painted.
  7. Haze


    Joined: Jan 10, 2007

    Posts: 3,017

    Would not touch diamond cut wheels with a barge pole in this country, one winter of salty roads and they are on the way out
  8. [TW]Fox

    Man of Honour

    Joined: Oct 17, 2002

    Posts: 155,136

    Why do manufacturers persist with this finish? It always leads to problems and is hardly leagues better looking than a properly painted finish. It must cost them a fortune in warranty claims.
  9. Nasher


    Joined: Nov 22, 2006

    Posts: 14,738

    Better off just getting wheels powder coated really, it makes the surface a lot harder wearing.
  10. Diagro


    Joined: Jun 3, 2012

    Posts: 8,899

    They look nice, but unfortunately they become ruined fast.

    Either get them replaced under warranty or have the set powder coated.
  11. CaptainRAVE

    Man of Honour

    Joined: Nov 21, 2004

    Posts: 31,926

    My diamond cut wheels look shocking. Was going to get them done, decided against it, then managed to whack them again. Would avoid diamond cut wheels if possible in future.
  12. OpenToSuggestions


    Joined: Aug 5, 2006

    Posts: 10,615

    Location: Derby

    Worked a treat on my 2007 focus wheels.
    They looked awful beforehand. Diamond cut wheels look snazzy in the showroom but they do not wear well.
  13. paintguy


    Joined: Feb 13, 2003

    Posts: 2,744

    Location: Sheffield

    Sure, but our wheel guy repairs dozens of these a week that have never been touched since leaving the factory so it isn't limited to poor refurb work.

    It's just a product of the poor system used. I'm no chemist but it just doesn't seem possible (or economical) to produce a clearcoat that adheres well enough to bare aluminium to prevent that kind of creeping corrosion.

    As others have said, I'd much rather manufacturers put this fad behind them and move back to proper powder or wet coated wheels, although it'll dramatically reduce how much work our wheel guy has :D