Section
Restore
Bring dead iron back. Rust removal, lye baths, electrolysis, and re-seasoning from bare metal.
Cast Iron Electrolysis Tank Setup: The Garage Rig, Step by Step An electrolysis tank is a plastic tote, washing soda, a steel anode, and a manual battery charger. How to build the garage rust-removal rig, step by step. 
How to Remove Rust From Cast Iron (No Matter How Bad It Looks) Rust almost never kills a cast iron pan. Remove it by severity — a scrub, a 50/50 vinegar bath, or electrolysis — then dry it hot and re-season thin. 
Is Rusty Cast Iron Safe to Use? (Yes, With Two Exceptions) Surface rust isn't a health hazard, and it scrubs off. Here's the severity ladder from orange dust to flaking scale — and the two problems that actually matter. 
Lye Bath Cast Iron Restoration: The Gentlest Way to Strip a Pan A lye bath strips decades of seasoning and crud off cast iron without touching the metal. The recipe, the safety rules, and why weeks in the tank are fine.