Something About Magnets

Last winter, when Susan Share and I were talking about the classes we’d be teaching together, we planned that Susan would demonstrate using magnets for closures. She has ways of hiding the magnets, including sewing mini-pillow cases for them, and has opinions about sizes. I included magnets in the packets for the people who took our class. Here’s one thing I learned: I will never, ever include them in packets again.

I loved using them, but packing them was a nightmare. We chose to use really strong adhesive-backed neodymium magnets. Each of the kits I packed included four magnets. Pulling them apart from each other so I could pack them just about drove me crazy. And then I needed to wrap them up really well so that they’d go through the mail without picking up metal along the way.

Simplest way of adding closure. This magnet from Adams came with an adhesive tab. Books is 4 inches high.

Still, they are so much fun to use. I’m just at the start of figuring out magnets, and I hope anyone who has something to add about these will chime in. I’m going to tell you the little bit I know so you can get started without me ever feeling compelled to send out even one more.

First thing to know is that not all neodymium magnets are equal. Prices are all over the place, and strengths differ. They come in many different sizes, but I’m going to talk about the one size that Susan recommended.

We bought the ones for our class at Adams Magnetic Products in Elmhurst, Illinois.

The selection at Adams is huge, and their product is great. I thought their shipping was high as were their magnets. As you can see, we bought 200 magnets and it cost us nearly 200 dollars. Seems to me that they have a $100 minimum. When using magnets as closures, the methods of hiding them create barriers, so having super strong attraction really lets these dots of power do their magic. I’d say Adams magnets are top of the line for power. What might have added to the cost is that the magnets we bought came with a strong adhesive backing. What’s important to note about this is that you have to order south pole and north pole magnets is you want the adhesive-backed ones to stick together.

Important note: for magnets without adhesive backing, a strong white PVA glue works well for sticking things down. Just be sure, Susan recommended, to roughing up the back of the magnet with sandpaper or something sharp so the glue will hold better.

Some of the people in our class wanted to source their own materials, which is always fine with me. What we told them was to look for neodymium magnets with a half-inch diameter and a thickness of 0.06, which is comparable to 1/16 of an inch. or 2mm . Any thinner, Susan warned, there’s chance of cracking, while thicker seems too thick.

I spent a long time looking for other sources. One of them totally caught my attention because they sourced out to be about 12 cents each, which was incredibly less that the Adams magnets., so of course I had to buy them just to check them out. Oh, but guess what, they’ve doubled in price since I bought them last January. Still, here’s the link to the MOSH Cool 100 Neodymium Magnets Round Disc N35 Super Strong Rare Earth 12mm X 2mm Fridge .Selling now for $24.00 instead of $12. You might be wondering if they are as strong as the Adams magnets? Absolutely not. Does that matter? It depends.

These weaker neodymiums have been perfect to use on some polyhedras that I’ve been making in a on-line class I’m taking through MoMath – National Museum of Mathematics- with Chaim Goodman-Strauss.

See the shape tucked inside the large triangle in the front two pieces? I made the one of the left first, according to Chaim’s patterns. The pieces fit together nicely by being glued to the inner polyhedra. I couldn’t stand not being able to get at that icosahedron in the center. What I needed was eight magnets to slip inside the interiors of the shapes to allow it to come apart. the super strong Adams magnets would have just been overkill.

The MOSH magnets worked perfectly for this. Not too strong, not too expensive, and worked just right.

Just because I’m curious I’ve just ordered magnets from a different source, Magcraft, that my friend Anita bought from. A pack of 24 cost $13.99 (free shipping) so total cost is almost 60 cents each. Here’s the link to the Rare-Earth Disc Magnets, 0.5 in. Diameter x 0.0625 in. Thick, 24-Count page that I ordered from. When these arrive I’ll give you the scoop on how they measure up to the others.

That’s it for now. If you have any magnet insights, please share!

Addendum: The Rare-Earth Disc Magnets that hadn’t arrived yet have now arrived. They are super super strong and are packaged really well, much more thoughtfully than the others I’ve bought, which, being magnets, actually makes a difference.

2 thoughts on “Something About Magnets

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