My aunt (90 years old) wants me to paint her rust barn roof. The metal still looks fairly strong but it has a nice coat of rust. I was thinking a cool seal product. But my commercial Sherwin Williams guy says they don't have a product that the rust will not come through in 18 months. He say using their products the rust must be removed first. I ask him about using Rust-Oleum primer for rusty surfaces first and he said he couldn't comment on other companies products. I know many here have addressed this problem. What is the best solution?
