A black film keeps rubbing off our black metal patio set. We purchased it from Agway & they have gone out of business. I have used Ivory dish soap & patio furniture cleaner from Home Depot to clean it. When the furniture is dry, the black still rubs off on our skin & clothes. The paint man at Home Depot suggested to spray paint it with Rust-oleum, which I have done. It has been a week since I painted it & the black stuff is still rubbing off. Any suggestions?