Distressing or aging wrought iron?

You will have to sand very well so no rust gets through, unfortunately what you will be doing is what you are taking off!! Seems stupid but if you want it black antiqued, you have to do this. There are some strippers out there that will strip metal but try to sand down so you can paint again, just getting to the green. Remember to tape off all the edges of bench. They have kits of antiquing wrought iron, Michaels etc., and it is just a black iron paint and then a chemical which will rust it. I have done many times, the longer and more you use the more orange it gets, have fun!!