Convert rust in place with a phosphoric acid converter

Brush or spray a rust converter product onto the rusted surface. The converter chemically transforms red iron oxide into a stable black iron phosphate coating that can be painted over directly. No scrubbing or soaking required.

Why It Works

Phosphoric acid reacts with iron oxide to form iron phosphate, a hard, dark coating that seals the surface and prevents further rusting. It converts the rust rather than removing it.

Tips

• Best for items you plan to paint — the black coating is not decorative but makes an excellent primer base
• Ideal for car frames, metal fences, gates, and structural steel where stripping to bare metal isn't practical
• Brand names include Rust-Oleum Rust Reformer and Loctite Extend
• Not suitable for tools or surfaces that need to be bare, polished, or food-safe
• Apply only to rusted areas — converter on clean metal leaves a poor finish