Rusty metal outdoor furniture, plant pots, and tools can transfer a terrible orange color to concrete, ruining an otherwise clean surface. Because of the way rust seeps in, those marks can be difficult to conquer completely, but there are ways to greatly reduce them and possibly remove them entirely.
A newer rust stain may lift with the mild acid of white vinegar. Pour vinegar over the stain, and let it sit for about 10 minutes, then scrub the stain with a stiff brush. If it’s having a mild effect, you can rinse and repeat this process to further reduce the stain until the concrete comes clean. For older or larger stains, you will need a commercial rust remover. Because these products contain much more powerful acid than vinegar, protection for your eyes and hands is very important, as is a mask to protect your lungs. Pay close attention to the product instructions, or call in an expert.