Remove rust with electrolysis (detailed method)

Connect the rusty item to the negative terminal of a battery charger and a sacrificial steel piece to the positive terminal. Submerge both in a washing soda solution (1 tablespoon per gallon). Run for 4-24 hours until rust converts to loose black residue, then scrub clean.

Why It Works

Electrical current pulls oxygen atoms away from the iron oxide and transfers them to the sacrificial anode. The rust literally falls off without removing any base metal — ideal for precision tools and antiques.

Tips

• Never use stainless steel as the anode — it releases toxic hexavalent chromium
• Work outdoors or ventilated — the process releases flammable hydrogen gas
• Use a manual charger, not a "smart" charger which may refuse the unusual load
• Reversing polarity (item on positive) will destroy the item instead of cleaning it
• Dry and oil immediately after — bare metal flash-rusts within minutes