Urgent help on stains on Aluminium

[jig459]

Hi Guys

Ive got this stain on the aluminium door surrounds of a RS4, it looks like salt marks but i cant get rid of them.

Any suggestions.

Thanks

Jack

 

[jig459]

wooops didn't think the picture would be that big. sorry

 

[BTB 500]

That looks like corrosion, is it bare aluminium or clear lacquered?

 

[jig459]

lacquered i assume its a factory finish. unless somthing has been put on there before that removed the lacquered

 

[BTB 500]

Hard to be sure from that pic. but looks like the sort of problem you get with alloys ... water gets under the lacquer and corrosion starts. It would probably have to be stripped back, polished out, and re-lacquered?

 

[jig459]

not good for a 3 year old car and a customer coming in 20mins lol
thanks for your advice though, much appreciated.

 

[tromppost]

Try posting on detailworld, they are a helpfull bunch

 

[EDZ649]

It's annodised Aluminium. Not much you can do with that I'm affraid.

 

[Sp!ke]

I wonder if it is covered by the corrosion warranty still?

 

[clever dicky]

Yeah you have aluminium oxide on the surface. Just like wheels. Something all aluminium does I'm afraid, natural process. Ironically the oxide will protect the aluminium underneath from being eaten further by what ever's doing it. If its bear aluminium you could carefully wipe it with a dilute amount of hydroflouric acid which will only dissolve the oxide. Pretty drastic and nasty stuff i'm afraid. But if its under a lacquer, then it would have to come off.
Have you considered paint ?

 

[Palfrem]

Hydrofluoric acid??

Be very, very careful.

Best to Google it first to understand its properties

 

[jaymanek]

Is it something you could remove and paint in a chrome effect paint or similar?

 

[NW_Merc]

Can you not use or rather try some metal polish like autosol? Or even Shiny Sinks as a start?

 

[adam87]

Strange place to ask for help considering you're doing it for work?

Did you use TFR?

Looks like something was left on the car for longer than it should have or the complete wrong product for the type of car.

Most cars with the chrome/aluminium strips will go like that over time, usually speeded up by TFR and other chemicals which are too strong and shouldn't be left on there for any length of time.

If it wasn't there before you started I hope you've got deep pockets for new ones.

 

[Superspec]

I don't think you'll get this off. Looks like degreaser or tar remover that's been left too long. You could try a cutting polish or a good metal polish but I think you're probably stuck with it.

 

[Simon_M]

Common fault on the RS4, check out rs246.com as there may be a few warranty claim successes on there.

S

 

[russb]

its most likely a caustic cleaner that has been used, this is the general mistake some people make when they see "non acidic" cleaner, these are more often than not high in alkalinity and subsequently not good for bare ally....you could try natural white vinegar, its acetic acid would or should start to counteract the alkaline but I havent tried it on this particular problem but its worth a punt at a quid....

 

[jig459]

thanks for all your help guys.

 

[TonyE280]

Are the wheels aluminium. If so this is how you do it

How to polish aluminum wheels