I have a white 97 Fzj80. I plan to paint it myself in the next year or so (and no, I'm not a professional painter, a novice at best). The roof has light surface rust that needs to be addressed now. I'm contemplating lightly sanding and applying white Rust Bullet White Shell. Has anyone done this? Is this a good idea? Bad idea? I'd appreciate any knowledgeable input. Thanks!