What's a good, secure way to attach neodymium magnets to a geocache?

Question

I've grabbed some neodymium magnets as a cheap way of attaching small geocaches to metallic objects such as road signs and poles. However, I'm not sure of the best way of attaching the magnets - tape tends to wear away, and over time with people constantly detaching / reattaching the cache I would imagine glue wouldn't necessarily last long either.

Is there a particularly secure way of attaching them, or is it just a case of doing the best you can and replacing when they go walkabout?

Answer 1

What I have always used is to have the magnet epoxied to the inside of the container.

Benefits:

• There is never a force pulling the magnet away from the container
• There is no weathering of epoxy
• No holes required

Answer 2

I have heard from others (and seen in various caches) that a good glue is sufficient. I believe that two-part epoxy will be good enough, but I'm not 100% sure.

It really depends on the plastic your container is made of, some glues work better on some types of plastic; some on others. If you know the type of plastic the container is made of, then look up which types of glue will work well. I hope someone else can provide some more solid information.

Some tips:

• Make sure the surface is clean
• Use some sandpaper or something similar on the plastic. This helps the bonding.
• Do not use hot glue on magnets! They can demagnetize!

(Some additional information can be found at this site.)

Another solution might be to screw it on. Either directly (provided the magnet has a hole) or by having a piece holding the magnet in place.

The problem is then to seal the holes for the screw in a sound way.