Things You'll Need
Instructions
Purchase muriatic acid from your local hardware store. If muriatic acid is undiluted, it removes rust. If it is diluted, it causes fast rust formation. Pour two ounces of the acid into a strong bottle made of plastic.
Soak copper wire in undiluted muriatic acid. Cover the bottle loosely -- if there's no space for air to escape, it may combust. It will take approximately one week for the copper to dissolve in the acid.
Mix the muriatic acid mixture with approximately 40 times that amount of water, or 80 fluid ounces. This dilutes the solution, so it won't clean rust, but rather create it quickly.
Dip the iron or steel coin into the solution with tongs, being careful not to splash. Lift it out and place it on a clean surface, not near any steel or iron. The coin should start to rust within the hour.