Burn marks on aluminium rims

[NICAT]

Hi Friends,
I bought those as a used rims.
2 of them has burn like marks on it.
It is unpainted wheel. I used some agressive home cleaning chemicals, but they did not help. I used even acid, it did not help either.
I think only solution is to use agressive polishing compound and pad. But i do not want the wheel to look chrome after polished.
There are some paint striping chemicals. Do you think it would help ?
PS: Marks are not very visible on the image, but they are dark grey patches which are noticable on the spokes
Any help is appreciated.

 

[ecotourist]

Is there a clear coat on them? The alloy wheels on my Honda are starting to look bad and I think it's because of deteriorating clear coat.

 

[NICAT]

No sign of clear coat it is bare metal.

 

[JohnnyG]

That's going to take a lot of work! The'll need to be sanded down and finished again, which won't be easy. Don't worry about them getting shiny as long as you can work to a good surface finish. A shot of that wheel acid will take any shine off if one develops.
Maybe there is a shop somewhere that can do it, but I don't know.

 

[ecotourist]

Are they brand name wheels? I wonder if it's just a low quality alloy.

Uncoated aluminum develops a grey mat finish when exposed to air. I wonder if an incomplete mix might give a mottled appearance.

I don't see any option other than leaving them alone or polishing them and working from there.

 

[oldhp]

The easiest, if not cheapest, would be to powder coat them.

 

[dwcopple]

I'd try bar keeper's friend and a stiff detail brush first