You can’t see it, but there’s a polymer coating inside your aluminum can. 🥫 @Phillip Cook uses chemistry to prove it! Working with lye, which is highly caustic and requires proper safety equipment (so please don't try this one at home), he makes a solution that reacts with the aluminum, converting it into a compound that dissolves in water. When the aluminum is gone, you can see the polymer coating! These coatings are useful because without them, acidic drinks could slowly corrode the aluminum

POLISH it Out with the NEW Hercules 3-inch Polisher from Harbor Freight