Removing oxidation from cast aluminum?

[Helf8704]

What do you guys use to remove oxidation from cast aluminum? I have an old school Turbo Dodge valve cover I'm trying to clean up to coat and there is oxidation all over it. I sandblasted it, tried using a scotchbrite pad, sanded it with 220 grit sandpaper but there is still oxidation in the metal. Will this show through if I coat over it? I'm guessing so, that is why I'm looking for other options. I do have a couple other things I'm going to try but any help would be appreciated. Thanks,

Jason

[sswee]

Re: Removing oxidation from cast aluminum?

In anodizing we use sodium hydroxide (lye) to etch the aluminum. It takes the oxidation right off but you have to watch the process because it wiil eat the part also. SS