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question about magnets?


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ok so I am placing a new cache and the magnet I had went strong anoth and I looked on amazon but gave up so dose any one have some good sugestions for good maganets that will hold a altoids can and stay on a booger

 

Earth magnets are your best bet IMO. You can get them on eBay.

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stay on a booger

 

Are you using the term to refer to glue? I've used altoid tins in the past, in protected locations. Never used glue. With a neodymium magnet you don't need glue. Just put the magnet on the inside of the tin. One caveat about altoid tins, even in a protected location expect to do a lot of maintenance. They rust up quickly. A baggie will not keep the logbook/sheet dry for very long.

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stay on a booger

 

Are you using the term to refer to glue? I've used altoid tins in the past, in protected locations. Never used glue. With a neodymium magnet you don't need glue. Just put the magnet on the inside of the tin. One caveat about altoid tins, even in a protected location expect to do a lot of maintenance. They rust up quickly. A baggie will not keep the logbook/sheet dry for very long.

 

The OP is from CA where it doesn't rain much so no biggie about rust. "Booger" is one of those green electrical cabinets you find around shopping centers and just about anywhere.

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ok so I am placing a new cache and the magnet I had went strong anoth and I looked on amazon but gave up so dose any one have some good sugestions for good maganets that will hold a altoids can and stay on a booger

 

Use rare-earth magnets; NdFeB is probably the best material.

 

BUT:

  • Don't glue them on the outside of anything, for two reasons. First, the glue won't hold them very well, and second, even if the glue holds, they are usually nickel-plated and the plating will come off.
  • If you really want them to stay put, get ring-shaped magnets and use screws to hold them on.
  • The 1/16" thick magnets tend to break (NdFeB is quite brittle), so I recommend 1/8" thick.

 

I've had good luck with Amazing Magnets.

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ok so I am placing a new cache and the magnet I had went strong anoth and I looked on amazon but gave up so dose any one have some good sugestions for good maganets that will hold a altoids can and stay on a booger

 

Use rare-earth magnets; NdFeB is probably the best material.

 

BUT:

  • Don't glue them on the outside of anything, for two reasons. First, the glue won't hold them very well, and second, even if the glue holds, they are usually nickel-plated and the plating will come off.
  • If you really want them to stay put, get ring-shaped magnets and use screws to hold them on.
  • The 1/16" thick magnets tend to break (NdFeB is quite brittle), so I recommend 1/8" thick.

 

I've had good luck with Amazing Magnets.

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Be very careful playing around with rare earth magnets, they can slam together and break, and/or trap the skin on your fingers and give you a blood blister.

 

A cheap way to get your hands on some very powerful magnets is to break apart a computer hard drive and use the magnets inside them. Have fun....

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stay on a booger

 

Are you using the term to refer to glue? I've used altoid tins in the past, in protected locations. Never used glue. With a neodymium magnet you don't need glue. Just put the magnet on the inside of the tin. One caveat about altoid tins, even in a protected location expect to do a lot of maintenance. They rust up quickly. A baggie will not keep the logbook/sheet dry for very long.

 

The OP is from CA where it doesn't rain much so no biggie about rust. "Booger" is one of those green electrical cabinets you find around shopping centers and just about anywhere.

 

Depends on where the sprinkler heads are located, found one a couple of months ago that was full of water, that was in Temecula Ca.

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I wish there was a good way to free up the magnets in speakers. Some of them are really strong, but I have not found a way to get to them. So many have gone in the trash.

For the more common types with a visible ring magnet, it takes some metal work to remove the frame and coil.

Something delicate like a cold chisel and hammer :rolleyes: will separate that. Then you have to deal with the plate with the hole (washer like plate) and the more solid plate and core piece. These are glued/epoxied on and again you need a means of separating them... like an old knife blade and hammer... They do come apart that way, but I always manage a few chips or more. Not sure if there is some solvent solution to that, or anything else.

 

For an easier pair of ring magnets (perhaps even stronger, but only about 2.5 inch diameter) try an appliance repair shop or just watch for an old microwave oven. Magnetron tubes have two magnets of slightly different sizes usually. Much easier to remove the parts around them. If you take an oven apart, watch out for the capacitor. Most ovens have bleed down resistors to drain them, but sometimes they are faulty or disconnected.

I've taken apart hundreds of these and only found one with a charge after two or three days unplugged.

Mostly you have to remove the mounting frame, often just twist the tabs and knock it off, then pry off the aluminum cooling fins. Magnets will simply slide off after that... don't mess with the tube, but recycle the extra materials. We had an electronics shop donating old micros and vcrs etc to a science program so we never wanted for most type of electronics... I like the early ones because they had more switches, wire, light sockets and so forth usable in our 'robotics' programs... Mostly we let kids explore the inards and design aspects in a safe, fun environment... first just take it apart, the next time pretending they had to put it back together... fun time.

 

I had a power point show on how to do the magnets on magnetrons, but my main computer box is down for repairs.

message me if you have any questions though.. or email. Not sure if I have one intact to photo again.

 

This might help you...

magnetron cutaway

 

Doug 7rxc

Edited by 7rxc
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As others mentioned, rare earth magnets are the best. I've had complaints about how difficult my caches were to move. As others mentioned there usually is no need for glue. All you need to do is put them inside the container and hold the the magnets in place with duct tape.

 

I get mine online at Lee Valley Tools. They have a huge assortment of sizes and shapes.

Edited by briansnat
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Michael's craft stores carry cards of 4-6 rare-earth magnets (depends on size).

 

I have successfully used JB Weld two-part epoxy to glue these to just about anything, and have help up quite nicely in the wild.

 

Exactly what I do.....I also get my small ziplocks for logs at Michael's.

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All being said, the ones I use in my DIY Magnetic Nanos are Neodymium (aka NdFeB, NIB or Neo magnet) which are a rare Earth magnet. Use hot glue to fix them to the cap.

 

Here in Brazil they are not easy to get, until now just found two stores with them at a good price (7x1.5mm for around $BR 0.60, around $US 0.27 the unit).

 

Just a curiosity photo of my DIY magnetic nanos, with a golf ball to compare the size. B)

 

Nano_zpsadd510fc.jpg

Edited by JPreto
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You can get some extremely strong magnets at Sciplus.com. Dirt cheap, you can get a lot of them. Their donut magnets are best, but the smaller rare earth magnets are pretty amazing too.

They also sell all kinds of containers and stuff that you can use for swag.

For logbook ziploc bags, you can check the jewelry section of your local craft store. They sell the small ones that are often used for selling merch at craft fairs.

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As mentioned before, hard drive magnets are seriously strong. I sometimes scrap the hard drive out of an obsolete desktop computer I'm disposing of and salvage the magnets. To get the HD apart, you'll usually need to buy a cheap set of mini-Torx bits. Then it's just a matter of taking the drive apart, which often involved peeling back decals to find hidden screws.

 

The magnets themselves (two in most drives) are mounted on steel brackets. I've used a hack saw to saw off any bends and then drilled a couple mounting holes in whats left of the bracket. That way I can screw the magnet to the cache and not use glue.

 

I have a small electrical box held to a steel light pole using this method. It's been in place for nearly two years and people have commented on how hard it is to pull off the pole.

Edited by bikebill77
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