In this video, we learn how to hollow out a penny. First, you need pennies that are dated after 1982, muriatic acid, a plastic container, and sandpaper. First, rub the edge of the penny on sandpaper until the silver color is exposed. Do this on two pennies, then place them in the plastic container. Now, while wearing gloves, pour the acid into the container so the pennies are completely covered. Now the pennies will start to bubble, leaves these in the acid for around six hours. Next, pour the pennies through a strainer and then into a glass with water and baking soda. After this, dry them off and drop them from a few feet up high. Your penny will be hollowed out!