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Rare Earth Magnets

 
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Marsha and Silent Bob
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Joined: 02 Sep 2003

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PostPosted: Sat Aug 13, 2005 9:22 pm    Post subject: Rare Earth Magnets Reply with quote

Rare earth magnets (87 of them) for $19.99: http://www.thinkgeek.com/cubegoodies/toys/770f/
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KC0GRN
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Joined: 22 Feb 2004

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PostPosted: Sat Aug 13, 2005 10:31 pm    Post subject: Reply with quote

Quote:
Post a find if you found the magnet


Hehehehe
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5savages
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Joined: 13 Feb 2005

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PostPosted: Mon Aug 15, 2005 8:28 am    Post subject: Reply with quote

That's a cool site! Thanks for the link. I had bought rare earth magnets from http://tinyurl.com/z0xu before but this looks like a better deal. I don't need any more, but I'll probably cave in to temptation and buy these.

Is there any better way to attach these to something than using superglue? I had experimented with superglue to attach one to the bottom of a pill bottle but the magnet is so strong that it force of pulling it away from metal surfaces eventually caused the magnet to break free of the bottle.

Pat
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Marsha and Silent Bob
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PostPosted: Mon Aug 15, 2005 8:38 am    Post subject: Reply with quote

5savages wrote:
I had experimented with superglue to attach one to the bottom of a pill bottle but the magnet is so strong that it force of pulling it away from metal surfaces eventually caused the magnet to break free of the bottle.

Make the finder have to unscrew the cap while the cache is in place. Rare Earth magnets aren't really suitable for removing/reattaching -- at least in my limited experience.
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KC0GRN
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PostPosted: Mon Aug 15, 2005 11:17 am    Post subject: Reply with quote

I believe one of the better glues would be the "Gorilla Glue" you can find at a hardware store. The application process though is kind of strange from what I've heard, but that stuff is supposed to permanently bond most anything (not like superglue, this stuff is more like an epoxy).
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5savages
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PostPosted: Mon Aug 15, 2005 11:20 am    Post subject: Reply with quote

KC0GRN wrote:
I believe one of the better glues would be the "Gorilla Glue" you can find at a hardware store.


Good idea! I even have some of this at home.
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Marsha and Silent Bob
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PostPosted: Mon Aug 15, 2005 11:41 am    Post subject: Reply with quote

It doesn't even work that well for regular magnets. I wouldn't recommend it.
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5savages
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PostPosted: Mon Aug 15, 2005 6:59 pm    Post subject: Reply with quote

I was messing around with my rare earth magnets and figured out that they are strong enough to work through the material I'm using them on. As such, I'll then glue them in the INSIDE of the container so the action of pulling the container off the host metal will be a compressive force at the glue joint, rather than a tensile force, thereby eliminating any tendency for the magnet to detach.

Last edited by 5savages on Thu Aug 18, 2005 11:52 pm; edited 1 time in total
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jrest
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PostPosted: Mon Aug 15, 2005 8:07 pm    Post subject: Reply with quote

Now that is a really good idea. Glued inside, and still working.
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GPSr
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Joined: 27 Sep 2004

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Location: St. Louis Park,MN

PostPosted: Mon Aug 15, 2005 9:58 pm    Post subject: Reply with quote

I have a couple super micro's ( the nitro pill containers) that I used epoxy to hold the magnets on. I even sandblasted them before attaching. One of them came off after about 3 months. I tried Gorilla glue and that wasn't a whole lot better. I ended up drilling a hole in the end of the container a few thousandths undersize and press fit the magnet in the hole. I did get some capillary action from rain so I put a dab of silicone on the magnet before pressing it in. So far it seems to work fine. Very Happy
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5savages
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PostPosted: Thu Aug 18, 2005 10:17 am    Post subject: Reply with quote

I had trouble using superglue and gluing a rare earth magnet to the inside of a film canister so I ended up taping it on the outside. I criss-crossed the tape on the bottom, then up the sides. Then I wrapped more tape around the circumference. Works well.

Today I found this FAQ on REM's:
http://www.kjmagnetics.com/faq.asp

They indicate JB Weld works well. I'll have to try it. I just bought their suprise sampler kit:
http://www.kjmagnetics.com/proddetail.asp?prod=JSS&cat=102
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RubberToes
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PostPosted: Thu Aug 18, 2005 10:43 am    Post subject: Reply with quote

5savages wrote:
I just bought their suprise sampler kit:
http://www.kjmagnetics.com/proddetail.asp?prod=JSS&cat=102


Interesting. Their Neo Mag Safty page includes this warning: "Never allow neodymium magnets near a person with a pacemaker or similar medical aid."

I'd be leery about placing such a thing in/on a cache. My father-in-law (with a pacemaker) has been out on a few cache hunts.
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5savages
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PostPosted: Thu Aug 18, 2005 2:27 pm    Post subject: Reply with quote

RubberToes wrote:

I'd be leery about placing such a thing in/on a cache. My father-in-law (with a pacemaker) has been out on a few cache hunts.


I'd think you'd have to get it pretty close for it to have any effect. Perhaps a warning on the cache page would be sufficient.
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knowschad
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Joined: 20 Jun 2005

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Location: South St Paul

PostPosted: Fri Aug 26, 2005 10:00 pm    Post subject: Reply with quote

You also have to avoid contact with moisture with REM's. They rust very quickly if not totally covered. But, boy, are they powerful! Radio Shack has some (about $2/pair) that are about 1/8" diameter and it still takes some effort to separate them. Magnets from newer harddrives can actually break a finger bone if you get caught between them as they're slamming shut.
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