How to remove yellow/brown stains from lionel aluminum cars

[Dobson]

I used a cloth to remove some of it with water then dried it. I then used mothers aluminum polish and it shines but the marks remain. Any recos for removing this from the silver dawn, silver streak cars?  

[Firelock76]

Hard to say without seeing it, but if the stain has penetrated deep into the metal, kind of like bluing or browning on a gun barrel, you may not be able to do anything else without damaging the metal.

Case in point:  I was restoring a US Model 1816 musket.  The barrel was brown and nasty, so I got to work cleaning it.  I got to the point where it had a satin shine on it like it was supposed to except for one VERY stubborn brown spot the size of a dime.  NOTHING could remove it.  Know what?  I called it a day.

So, maybe you should just "call it a day"  and be happy with what you've got.   

[Prairietype]

This question got me to thinking because I have this type of staining on an aluminum baggage car. I dabbed a q-tip with bleach and did a test. Most of the staining rubbed right off. The only spots that did not clean seems to be as mentioned above, vis., so deeply ingrained as to be almost blued. These are much less noticeable now after the bleach application.

[Firelock76]

Take it easy with the bleach and wipe it off after you're done.  The chorine in the bleach can corrode brass and steel, I'm not sure about aluminum but I wouldn't take the risk.  Ammonia will attack aluminum as well, so I wouldn't use it either.