Best way to clean old aluminum for TIG

[Wookie]

I'm a welding noob, so I don't know how nitric acid cleans aluminum, but when I worked for an electronics manufacturer we used to use it to burn holes in the cases of silicon chips so the wafers inside could be examined under a microscope.

Be CAREFUL with nitric acid. Do it outside with a fan blowing the fumes into your neighbor's place. If you smell it at all, you're doing permanent damage to your lungs.

nitric acid works well we use it at work to prep alum to be welded removes the oxide layer and cleans it