Any ideas on how to get black stains off alum?

Some mag/aluminum polish should do the trick

 

Mothers wheel polish.

Worked great for me.

 

I think some degreasers like Simple Green stain/corrode aluminum with prolonged exposure (I've seen this mentioned in other threads). If this is the case, then it probably requires removing quite a bit of surface to make them it away -- might be better to replace them than try to polish them out. I bought a set from Daniel at Ricambi and they were reasonably priced (don't remember how much off the top of my head though).

 

I use Solvol Autosol paste, it’s very good at removing even the worst marks and stains from metal. Highly recommended.

 

Catsup,

We used it to polish the deckplates in the Navy..... no kidding.

 

Soak them in Coca Cola.

 

0000 steel wool with meguiars scratch remover or mothers aluminum polish

 

You beat me to it.

 

Christopher -- there are some very interesting suggestions in this thread -- did any of these solve the problem?

If all else fails, I have an extra set of valve stems I could send you -- I replaced all of my valve stems last time I had the wheels/tires off, but the old ones were fine if you need them.

 

The best all-around stuff I have found is called Novus. They use it for polising out small scratches in plastic lenses. Works well on just about anything, but in some cases it will take a while because it is so fine..

 

'Aluminum Brightener", sold at NAPA stores.