Earth Magnets

[+russell_53040]

Want to use them for a cache. Was wondering if anybody uses them? Has anybody got hurt using them? Has anybody broke one? Any input on this would be appreciated. Also is there diffrent types of earth magnets. Thanks

Edited October 4, 2005 by russell_53040

[GeoWorms]

I have broken them--they are pretty fragile. They can break just from the force of them snapping together.

 

Many places sell them coated in epoxy, which makes them much more durable--and the adhesive sticks to them better.

[+bitbrain]

I have used them a few times. One of my current caches has been attached to a metal structure for about three years now using a single circular rare-earth magnet. It sticks real good.

 

I have broken several rare-earth magnets that I salvaged from dead hard drives, but I have not broken one of my circular magnets.

 

As for getting hurt, I have managed to pinch my fingers pretty good, but no real damage. One of my travel bugs, Bit's Magnetic Personality, is a pretty much just a couple of these super magnets from a hard drive.

 

The image below is a sample of the selection available from Lee Valley Hardware or any number of other online sources.

[+russell_53040]

How big are the ones from hard drives? Thanks for your imput all.

Never mind just went to look at your TB. Are those pretty strong?

Edited October 4, 2005 by russell_53040

[Team Firebird]

How big are the ones from hard drives? Thanks for your imput all.

Never mind just went to look at your TB. Are those pretty strong?

about 2 inches lond, one inch wide, and shaped like an arc. Carful when you store two of them together. They might become one.

[+Prime Suspect]

Want to use them for a cache. Was wondering if anybody uses them? Has anybody got hurt using them? Has anybody broke one? Any input on this would be appreciated. Also is there diffrent types of earth magnets. Thanks

Earth magnets are a total scam. I've tried them, and not a single one would stick to earth.

[+Butano]

Want to use them for a cache. Was wondering if anybody uses them? Has anybody got hurt using them? Has anybody broke one? Any input on this would be appreciated. Also is there diffrent types of earth magnets. Thanks

Earth magnets are a total scam. I've tried them, and not a single one would stick to earth.

Did you try to stick it to the north pole?

[+Jester2112]

OK, I give. What's the difference between a rare earth magnet and the ones I find on my fridge. Other than these appear to be metal, chrome maybe, and the ones on my fridge appear to be rubber??? I'm assuming from the posts about their strength that that's the biggest difference. What makes them so strong? Is it the metal their made from? Excuse the ignorance. My only experience with magnets is from the fridge and speaker magnets.

[+Prime Suspect]

But seriously folk...

 

Ceramic magnets are strong, but fragile. I've had them shatter, just by having two close enough together that they attracted each other. The force of the hit was enough to break one of them.

 

Neodymium magnets are not as fragile, really really strong, and a bit dangerous. Over time, if left next to the skin (like leaving one in your pocket) they can cause blood welts. They're actually pulling the blood cells (their iron, actually) to the skin's surface. And you thought that scene in X-Men 2 was totally bogus.

 

Hardware stores sell small neodymiums, but the big ones usually have to be ordered from scientific supply shops. The little one's should suit most geocaching purposes.

Edited October 4, 2005 by Prime Suspect

[+briansnat]

I've pinched my fingers and received some nasty, little blood blisters trying to separate earth magnets. The hardest thing about them is getting them apart. Otherwise they are great. A small one will hold a good sized micro. A larger one will hold an ammo box. You don't even have to worry about glue. Put it inside the container and it will hold.

 

I put them inside and just hold them in place with duct tape. The only prob is that everything inside that is metal wants to stick to the magnet.

Edited October 4, 2005 by briansnat

[tossedsalad]

I bought a bunch of rare earth magnets from a vendor on eBay and I love them! Even the tiny ones are pretty strong. I just finished a cache where I hollowed out a figurine from Walmart and used a thin steel plate on the bottom to cover the opening. I used three 1/4" x 1/16" magnets to hold the plate on. Once I filled it with swag, the bottom would fall off, so I added three more and now it is a tight fit. I think the six magnets cost me about a buck. The largest magnets I got are 3/4 x 1/8 and will very easily pinch your fingers. I also let them slam together once and it broke one of the magnets. They are shipped with plastic spacers to keep this from happening, but if you aren't careful, they will get away from you.

 

The refrigerator door seal uses ceramic magnetic powder cast into vinyl. This gives it a lot less strength compared to a ceramic magnet and tons less compares to a rare earth magnet.

[+russell_53040]

Thanks for all the imput. I am going to try the hard drive one first because I have a junk one but I have a feeling it is going to be to big for what I want to use it for. Thanks again Russ

[+chris-mouse]

How big are the ones from hard drives? Thanks for your imput all.

Never mind just went to look at your TB. Are those pretty strong?

 

The size depends on which hard drive model you're taking apart to get the magnets from. Most of them are about half an inch wide by an inch or two long, shaped in an arc. Some models use two smaller magnets instead of one bigger magnet.

The magnets I have all came glued to a metal backing plate. Unless you're going to glue the magnet to a solid piece of steel, like an ammo can, leave it attached to the backing. The main effect of the backing plate is to make the magnet MUCH stronger on the side opposite the plate. It also helps to protect the magnet from shattering by absorbing some of the impact when the magnet snaps against another surface.

The metal backing plates also have mounting holes that were used to bolt the magnet into place inside the hard drive. Those same holes can be used to bolt the magnet to the outside of a cache container. Two of these magnets would be enough to hold an ammo can securely in place on the underside of something like a steel beam.

[tossedsalad]

What size would you like? I can send you a couple if that would help. I have the following round neodymium magnets...

 

1/4 x 1/16 - >1 lb pull

5/16 x 5/32 - > 3 lb pull

1/2 x 1/8 - > 5 lb pull

3/4 x 1/8 - >> 10 lb pull, almost 20 lbs

 

The smallest size are very inexpensive and I think I paid about a $1 to $1.50 (including shipping) for the largest size. So far I have only used the 1/4 inch and 1/2 inch sizes. I got them from Emovendo on eBay.

 

FYI, when I looked around town all I could find were the ceramic magnets (which are not terribly weak, they are just not as strong as the rare earth magnets), until I went to Jo-Ann Fabrics. They had at least two sizes of rare earth magnets, IIRC.

 

Also, I don't put magnets on the outside of the container since you are then counting on the glue to hold the magnet to the container. I put them on the inside where the glue only has to keep them from moving. On the inside the pull is weaker because of the increased distance to the metal mounting point.

[+AtoZ]

Problem with magnets is they can replaced any where use velcro, I know some one will hate it.

 

cheers

[tossedsalad]

Problem with magnets is they can replaced any where use velcro, I know some one will hate it.

 

cheers

Can you translate that to English please? I have no idea what you are trying to say.

[+russell_53040]

What size would you like? I can send you a couple if that would help. I have the following round neodymium magnets...

 

1/4 x 1/16 - >1 lb pull

5/16 x 5/32 - > 3 lb pull

1/2 x 1/8 - > 5 lb pull

3/4 x 1/8 - >> 10 lb pull, almost 20 lbs

 

The smallest size are very inexpensive and I think I paid about a $1 to $1.50 (including shipping) for the largest size. So far I have only used the 1/4 inch and 1/2 inch sizes. I got them from Emovendo on eBay.

 

FYI, when I looked around town all I could find were the ceramic magnets (which are not terribly weak, they are just not as strong as the rare earth magnets), until I went to Jo-Ann Fabrics. They had at least two sizes of rare earth magnets, IIRC.

 

Also, I don't put magnets on the outside of the container since you are then counting on the glue to hold the magnet to the container. I put them on the inside where the glue only has to keep them from moving. On the inside the pull is weaker because of the increased distance to the metal mounting point.

Thanks for the offer. I will let you know.

[+Isonzo Karst]

I was having trouble with AtoZ's post - so I translated it to Spanish then back to English (Babel Fish) it's much clearer now:

 

The problem with magnets is they can replaced nobodies where velcro of the use, I knows that some will hate it.

 

The hate part is coming thru

[+bushwackin' schmo]

I got a couple of magnets fron a hard drive then dropped them in my pocket with my wallet, bad news all my credit cards were wiped clean. My daughter got her fingers caught between the same set of magnets. Oh yeah the cache the magnets were used with got mugged...these magnets must have been cursed like Gregg Brady's Tiki idol.

[+teambeener]

Here. I translated AtoZ's post into Korean and then back to English. I am pretty certain this clears up the confusion:

 

About thing dog hating it the use bell crow, or to the place which is Iss problem them is a possibility of doing to the magnet and multi it is what it transfers it is.

[+BigFurryMonster]

What =is= an 'earth' magnet anyway?

[+Prime Suspect]

What =is= an 'earth' magnet anyway?

The correct term is rare-earth magnet.

 

Edited October 5, 2005 by Prime Suspect

[+briansnat]

What =is= an 'earth' magnet anyway?

My wife seems to think I am. I always return from my cache hunts covered with dirt.

 

Seriously, rare earth magnets are magnets composed of alloys of the Lanthanide group of elements. The two Lanthanide elements most prevalent in the production of permanent magnets are Neodymium and Samarium. There are numerous alloy formulations of rare earth magnets covered under many different patents but the most common commercial varieties are Neodymium-Iron-Boron (NdFeB) and Samarium Cobalt (SmCo). Neodymium-Iron-Boron magnets are the most advanced commercialized permanent magnet material available today.

 

Also see the Wikipedia's def.

 

They are extremely powerful magnets.

[+welch]

Problem with magnets is they can replaced any where use velcro, I know some one will hate it.

 

cheers

Can you translate that to English please? I have no idea what you are trying to say.

Oddly I wasn't confused till I read that question....

after thinking about it, I still think they mean if you use a magnet some dup can put it back anywhere it will stick (ie. the wrong sign, the other end of the bench, wrong side of the light pole, etc). But if its velco they have to put it back where the other half of the velco is, otherwise it won't stick.

At least thats what I think they meant, maybe I have it wrong

[tossedsalad]

Figures that the Welch could translate it. If they understand Welch, they can understand anything!

 

Thanks, I do get it now. And thanks to everyone else who tried to help with the various translations. You were trying to help, weren't you???

 

The problem with Velcro is that it is a "permanent" alteration to the location which is not allowed if you interpret the gc.com guidelines in a strict manner. I recently placed a magnetic cache to an aluminum sign by gluing a can lid to give the magnet something to stick to. But I used a type of sealer that will peel off easily, so I don't consider that a permanent change.

 

But then again I used a rock to hold a micro by drilling a hole for a tube. I guess the hole is a permanent change, but the rock came from somewhere else, so that makes it not permanent. One must observe the guidelines when placing caches!