Will Neodymium Magnets Rust?
Yes, they can. Neodymium magnets are about 64 to 68% iron, so they rust if moisture gets through the protective plating. In dry, indoor use the standard nickel-copper-nickel plating prevents rust for years. Humidity, salt, acids and scratches speed it up. For damp or outdoor use, choose an epoxy or plastic coated magnet.
What Speeds Up Corrosion
High Humidity
Condensation reaches tiny flaws in the plating.
Salt and Acids
Salt water, salty air, sweat and acidic cleaners attack plating quickly.
Scratches and Chips
Any break in the plating exposes the bare alloy underneath.
Heat and Moisture Together
Warm, wet conditions corrode faster than cool, dry ones.
How to Prevent Rust
- Store magnets dry, in a sealed bag or box with a desiccant packet if your space is humid.
- Dry them right away if they get wet.
- Avoid chipping by letting them come together gently and using spacers.
- Pick the right coating for wet or outdoor use: Epoxy, Plastic or PVC Sewing Magnets for washables.
- Seal exposed edges with clear epoxy or lacquer if a plated magnet will see occasional moisture.
Already Seeing Rust?
Light surface spots can be wiped off and the magnet sealed with clear lacquer or epoxy. If the plating is peeling or the magnet is crumbling or flaking powder, replace it: corrosion has started eating into the magnet and it will keep losing strength.