Old milk cans fit in with a variety of decors and make for an impressive focal point when accessorizing a cottage or farm-style room. Outside, the cans function as garden accessories. Old milk cans are typically made from tin. In earlier times, farmers would use "fresh raw acid" to re-tin their milk cans and remove rust. In modern times, we have commercial derusting products as well as homemade remedies to remove rust from an old milk can.
Rub fine-grit sandpaper over the rusty spots of the can to loosen the rust.
Spray a rust-dissolving agent all over the can.
Run a wire brush over the can to lift off the rust. Spray on more of the rust-dissolving product, if necessary.
Rinse off the old milk can with water. Inspect it to determine if rust remains and, if so, repeat the scrubbing.
Dry the can with a cotton towel.
Potato, Salt and Baking Soda
Scrub the milk can with a steel-wool pad to loosen the rust patches.
Cut a potato in half, either lengthwise or widthwise, based on which cut will give you the best grip on the potato.
Dip the cut potato half into a mixture of 3 tablespoons of baking soda and 3 tablespoons of salt to coat.
Rub the potato vigorously and with hard pressure over the milk can's rust. Re-dip the potato into the baking soda and salt as necessary to keep it coated.
Rinse off the can with water and dry it thoroughly with a cotton rag.