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.
Best Answer: Cooking Temperatures for Perfect Baked Potatoes Everytime: Conventional or Regular Oven: Medium-size potatoes (about 5 ounces or 150 grams each) 45 minutes at 400 degrees F. 60 minutes at 350 degrees F. 90 minutes at 325 degrees F. Place the potato directly on the oven rack in a preheated oven. Potatoes are done if tender when pierced with a fork and the internal temperature reaches 210 degrees F. --------------------------------------... Bake on racks of oven until tender. The higher the oven temperature, the shorter the cooking time will be and the crustier the skin.