I have an old bathtub and a sink that have been upside down in the field now for some time. How do I tell what kind of metal these things are? Is it worth loading them up (they are very heavy) and hauling them to the scrap metal place to sell? Any idea of what they might be worth? I don't know if they are cast iron or what. The tub is one of the kind that you place against a wall and build a wall at the end. I hung on to it thinking I might use it as a stock tank but I really don't need it.