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.
Roasted potatoes take around 50 minutes to cook. You may need to adjust this cooking time to suit your preferences. As a general rule, the longer you cook the potatoes, the crispier they will be. Of course, overcooking leads to dried out or burned potatoes. Don't forget to allow 10 to 15 minutes to wash, peel and cut the potatoes. For a gas oven, heat it to 350 degrees Fahrenheit for roasted potatoes. The oven should be at the correct temperature before you put the pan of potatoes into it. If you're using a fan oven, set it at 400 F.