Acid and Copper Solution. 1  1. Ensure that the metal you are working with will rust. 2  2. Measure some hydrochloric acid into a plastic bottle. 3  3. Dissolve a bit of copper in the hydrochloric acid.  4. Dilute the copper and acid solution with 1  water. 5. Clean your steel or iron thoroughly.  6. Apply the acid 1  solution. 7. Allow the metal to  rust.
Quick Answer. Depending on size, potatoes should bake in the oven for around 50 minutes to 1 hour. Flipping the potatoes every 20 minutes during the baking process helps to ensure consistent baking throughout the entire potato. Continue Reading.
Oven-Baked Potatoes. See what to do: How To Bake a Potato in the Oven. Preheat the oven to 425Â°F. Rub the potatoes with olive oil, sprinkle them with salt and pepper, and prick them with the tines of a fork. You can lay them directly on the oven rack or place them on a baking sheet.