Rust converters chemically change remaining iron oxide into a more stable surface. Learn when they make sense, how to prepare metal correctly, and how different products compare.

Rust converter vs. rust remover

They do different jobs. A rust remover takes rust off and leaves bare metal. A rust converter is applied over remaining rust and reacts with it to form a stable, paintable layer.

Removers suit parts you can clean back to bare metal. Converters suit pitted or hard-to-reach areas where some rust will remain. Many repairs use both: remove what you can, then convert what is left.

How to use a rust converter

• Remove loose scale: Converters react with firmly attached rust, so brush off loose flakes first.
• Clean/degrease: Oil, grease, and dirt block the reaction.
• Apply correctly: Follow the manufacturer’s coverage, number of coats, and temperature and humidity limits.
• Cure time: Allow the full cure time on the label before topcoating.
• Topcoating: Most converters need a topcoat for UV and moisture protection. Check the product label.

Types of products

• Spray: Aerosols for quick coverage of large or awkward areas.
• Brush-on: Liquids for controlled application into pits and seams.
• Converter + primer: Products that treat rust and act as a primer in one step.
• Paint systems: Multi-step kits that pair a rust treatment with primer and topcoat.

Brands & comparisons

Brands we plan to cover:

• POR-15
• Corroseal
• Rust-Oleum
• Eastwood
• Ospho

Future testing

Underbody Lab plans to compare application, coverage, curing, durability, and real-world performance as original tests are completed.