This painless condition occurs when the little bumps on your tongue grow long and trap bacteria that live in your mouth -- making the tongue look black and hairy. Causes can include antibiotic use, poor oral hygiene, smoking, drinking a lot of tea or coffee, and not producing enough saliva.
Hello, Jie. The word passivate is a bit troublesome because aluminum cannot be passivated in the same sense as stainless steel; but it can be passivated in the same sense as zinc plating, i.e., with a chromate conversion coating.
After you clean and rinse the surface, you will need to prime all areas of exposed aluminum (that is, where you can see the metal), or where any of the white salts were. For the primer, use a latex corrosion-inhibitive primer. Ask for this at a paint store.fter you clean and rinse the surface, you will need to prime all areas of exposed aluminum (that is, where you can see the metal), or where any of the white salts were. For the primer, use a latex corrosion-inhibitive primer. Ask for this at a paint store.