To repair workbench rust, always wear safety goggles and gloves to protect skin and eyes from rust flakes. Use steel wool to scrub away rust and brush away excess flakes with a dry cloth. Apply naval jelly and allow it to sit for up to an hour to dissolve the remaining rust, wipe clean with a dry cloth, and repeat the process until you have hopefully removed all of the rust. You can also try using mineral spirits to remove rust using the same method. To prevent rust from causing serious damage, treat any visible rust early, and keep your bench dry and clean to prevent it from forming in the first place.