Can magnets be used outdoors?

Yes, neodymium magnets can be used outdoors if you choose a suitable version: epoxy for sheltered places, plastic or rubber-coated for rain and wet weather. An ordinary NiCuNi magnet often rusts outdoors within a few months.
By Team Magnetenspecialist
2 min read

Short answer: yes, but not every version. An ordinary nickel-plated (NiCuNi) neodymium magnet often starts to rust outdoors in rain or condensation within a few months. For outdoors choose epoxy (sheltered, under a canopy), a plastic casing (wet, rain) or a rubber casing (on paintwork or a car). Frost and cold are not a problem; strong sun behind glass can get too hot, though.

Which magnet for which outdoor situation?

Situation Advice
Under a canopy, carport, shed epoxy-coated magnets
In the rain, garden, facade plastic-coated magnets
On a car, caravan or painted metal rubber pot magnets
Salt water, beach, harbour fully encased, and rinse with fresh water after use
Magnet fishing a fishing magnet with a steel pot; dry after use
Built into wood or plastic, fully sealed NiCuNi is sufficient if moisture really cannot reach it

Outdoor temperature

  • Cold and frost: no problem. Neodymium even gets slightly stronger in the cold.
  • Sun: on a dark surface in full sun or behind a car window it can reach 70 – 90 °C. Above approx. 80 °C a standard magnet permanently loses strength. See magnets at high temperatures.
  • Frost and water: water freezing behind a damaged coating can push the coating off further. An intact coating is therefore important.

Tips for a long life outdoors

  • Do not let magnets snap against each other or against steel: a damaged coating is the start of rust.
  • Mount them so that water can drain away and does not stand.
  • Glue with a waterproof adhesive that covers the magnet, for example two-component epoxy. See how do you mount a magnet?
  • Check once a year for rust or white deposits and replace if necessary.
  • Mind the counter plate: a steel strip or plate can rust too. Choose galvanised or painted steel.

Frequently asked questions

Are neodymium magnets waterproof?

A magnet does not dissolve in water, but the material rusts as soon as water reaches the NdFeB. Only a fully sealed casing is truly waterproof.

Can I use a magnet for a sign or facade advertising outdoors?

Yes. See magnetic mounting of facade signs for suitable versions.

How long does a magnet last outdoors?

A plastic or rubber-coated magnet lasts for years outdoors. So does an epoxy magnet under a canopy. An ordinary NiCuNi magnet in the rain often only a few months.

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Need help choosing? Use the Magnet Advisor or contact us.