Rust inhibitors are designed to prevent new corrosion, not treat rust that has already formed. If rust is present, it’s best practice to thoroughly clean the surface before applying any inhibitor. This can be done using mechanical abrasion, chemical rust converters, or a rust remover such as those in the ZERUST® AxxaClean™ series, which are effective even in cracks and crevices.
Once the metal is clean and dry, a ZERUST® rust inhibitor can be applied to provide ongoing protection. Applying inhibitors directly to rusted surfaces can reduce their effectiveness and may trap moisture, actually accelerating corrosion instead of preventing it.