Q&A for How to Remove Rust Stains from Paint

Use a primer that's formulated for metal. Make sure it's labeled as "oxidizing" or "rust-resistant." This will protect the metal once it's painted.

Get a rust removing solvent and this should be able to remove the rust. Test it out on the paint first if possible to make sure it won't damage it.

Before you paint a metal object, first sand the surface with 80-120 grit sandpaper, or lightly scuff it with wire brushes. Then, paint it with an oxidizing primer, which will help inhibit rust growth.

If the wood is removable, then remove it to avoid any further damage to the wood. Or, for minimal damage, use a nail-set to drive the old nails in deeply and out of the surface rust zone. Then, install new nails that are counter sunk and covered with putty or caulk before re-painting. If the wood's not removable and the nail-set doesn't seem to get them going anywhere, then you have to dig out some wood and get a good bite with large slip joint or channel lock pliers - extremely strong clamping that can't be equaled by anything else. You can try drilling the old nails down, but that rarely, if ever, works, though a grinder works and also does a lot of damage.

Try soaking them in cleaning vinegar. You might want to drench a paper towel in the vinegar and somehow fasten it to the rust areas. When the metal turns black (a few minutes or hours), rinse off the blackened rust. Now you can use nail polish or other paint to cover it up.