Bonding Magnets to Plastic - Best Adhesive?

[+GiantCappuccino]

I am looking to bond a couple of strong magnets to the inside of a plastic container.

 

I have tried Gorilla glue without success.

 

Anyone know what really works well for this application?

[+Manville Possum]

I use 3M brand Plastic Emblem and Trim Adhesive from Walmart.

[+Cardinal Red]

I am looking to bond a couple of strong magnets to the inside of a plastic container.

 

I have tried Gorilla glue without success.

 

Anyone know what really works well for this application?

 

Depending on magnet size, and if your container is a Lock and Lock style, hold the magnets in place with some Duct tape or perhaps decorative stickers. I have personal experience with one hide. American Flag stickers worked great with very strong magnets to secure it underneath a Flag Disposal Drop-off Box (a re-purposed Mail Box).

[+narcissa]

I think any glue is bound to fail over time and exposure to the elements. Duct tape isn't glamourous but it can be wrapped around and holds everything together.

 

If you need to use glue based on design, something like JBWeld will hold up for a while but you should redo the bond once a year.

[+Chofman1]

I used liquid nails on the outside of a plastic matchstick holder that has worked well so far

[+GiantCappuccino]

The duct tape worked perfectly!

 

Thanks for the help!

[+funkymunkyzone]

I find the best method to be sticking the magnet(s) to the *inside* of the container. I typically use no more nails and to get the magnet to set in place, a hold it there with some temporary magnets on the outside.

[+MartyBartfast]

When gluing magnets to tupperware boxes I usually:

 

• put the magnet inside, not outside
  
• clean the area well with methylated spirits to remove any remnant of release agent from the manufacturing process
  
• roughen up the plastic well with sandpaper
  
• use a 2 part epoxy glue (e.g. Araldite in the UK)
  
• spread the glue well around and over the magnet so the magnet is encased in a blob of glue
  
• cover the end result with duct tape.
  

 

The ones where I've done this have lasted until they get muggled

[+briansnat]

I just use duct tape when attaching to the inside. The outside is a different story. Every glue I've tried (and I've tried all kinds) eventually fail. So placing a powerful magnet inside and holding the magnets in place with duct tape is the way to go.

[+paticpatic]

I use a high temp Loctite to hold magnets to containers.

[+hzoi]

When gluing magnets to tupperware boxes I usually:

 

• put the magnet inside, not outside
  
• clean the area well with methylated spirits to remove any remnant of release agent from the manufacturing process
  
• roughen up the plastic well with sandpaper
  
• use a 2 part epoxy glue (e.g. Araldite in the UK)
  
• spread the glue well around and over the magnet so the magnet is encased in a blob of glue
  
• cover the end result with duct tape.
  

 

The ones where I've done this have lasted until they get muggled

 

Seconded. Hot glue gun also works.

[+J Grouchy]

I found these nice double-sided adhesive squares that are good for adhering rare-earth magnets. I then go over the whole deal with black electrical tape and/or duct tape for good measure. A couple of these are still around and standing up well three to four years in.

[+frinklabs]

I have a test Lock n Lock container outside that has magnets attached to its outside with Sugru

 

It has handled the summer ok so far; we'll see what's its condition in the spring.

 

Has anyone else used this for caching successfully or otherwise?

[+Modeer43]

I usually add two magnets to the outside, slide a piece of heat shrink tubing over, and heat with heat gun. Never moves or comes off. The tubing comes in all sizes and colors.

[+SeattleWayne]

If you buy a big enough magnet you might try using a small enough drill bit and drilling through to attach a small bolt with nut. That'll probably do best to survive the elements.

[+kunarion]

If you buy a big enough magnet you might try using a small enough drill bit and drilling through to attach a small bolt with nut. That'll probably do best to survive the elements.

A plan that works pretty well, particularly with the oily surfaced plastics of many cache containers, is to use a combination of mechanical attachment (tape, hardware, etc.) and a flexible adhesive to grip and seal. I've tried many kinds of adhesives, and just when I'm certain I've got the perfect kind, tested it, and I know for a fact that it's durable, it at some point in the life of the cache (such as upon the first find) pops right off as if there was no glue at all. Or it melts or breaks down or changes to a non-sticky material, or whatever. Extra hardware keeps it together a little longer.

[+JohnCNA]

A plan that works pretty well, particularly with the oily surfaced plastics of many cache containers, is to use a combination of mechanical attachment (tape, hardware, etc.) and a flexible adhesive to grip and seal.

 

Some of the places that sell magnets have versions already pre-drilled and countersunk. I have had some of the rare earth magnets crack when I tried to drill through them.

[+coachstahly]

I usually add two magnets to the outside, slide a piece of heat shrink tubing over, and heat with heat gun. Never moves or comes off. The tubing comes in all sizes and colors.

I like this idea. Thanks.

[+fbingha]

If the magnet is on the inside of the plastic and the outside of the plastic is to attach to the metal surface, then the best option is not in doubt. You don't need to wonder what type of plastic is this, what kind of glue works with this plastic. No glue will do a better, more thorough job than duct tape, across all plastic types. Not the cheap thin duct tape, the thick good stuff. If the glue needs to go on the outside of the plastic then the best outcome can be reached by giving the glue something to bite into. Sandpaper isn't enough. Either drill holes to allow the glue to penetrate or attach a protrusion (screw) that the glue can grasp.

 

If your cache is small enough to fit inside heat shrink tubing, than you can use that. You could also place the magnets on and wrap it in duct tape. Wrapped is good. A square of duct tape, on the outside, of the container, will not be sufficient to keep the magnets attached.

Edited December 1, 2016 by fbingha

[+narcissa]

A plan that works pretty well, particularly with the oily surfaced plastics of many cache containers, is to use a combination of mechanical attachment (tape, hardware, etc.) and a flexible adhesive to grip and seal.

 

Some of the places that sell magnets have versions already pre-drilled and countersunk. I have had some of the rare earth magnets crack when I tried to drill through them.

 

Does this method also require drilling a hole in the container? I would be concerned about that.

[+M 5]

A plan that works pretty well, particularly with the oily surfaced plastics of many cache containers, is to use a combination of mechanical attachment (tape, hardware, etc.) and a flexible adhesive to grip and seal.

 

Some of the places that sell magnets have versions already pre-drilled and countersunk. I have had some of the rare earth magnets crack when I tried to drill through them.

 

Does this method also require drilling a hole in the container? I would be concerned about that.

 

You just have to use a rubber washer to re-waterproof it. Done it a few times with no issues