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Sifting and sorting: summer beach magnetorheological fun

Yes, it’s not summer anymore, yet I just was sifting through my blog and found this post I never activated. So keep this in mind for the coming summer. Or if you’re like us, you’ll enjoy a winter beach as well!

When I was homeschooling my daughter, I often wrote about things that we’d do to satisfy her need for tactile stimulation and goal-oriented projects. She just loves getting her hands into something, and when she was small, that meant our house could be, ahem, rather chaotic!

Recently she and her father were talking about iron filings (why were they talking about iron filings? these are the sorts of questions it’s best not to ask!) and he suggested that she get some from the beach. It being summer, we were able to indulge this whim without worrying about getting homework done. (Ah, homeschooling a younger child, how I miss you!)

We made our way to the beach with two strong magnets and three ziploc bags. The bags are important: Of course, you need one to store the filings into. The other two are to cover the strong magnets, because the thing her father warned her about came true almost immediately: if you drop a strong magnet into sand, you end up with a strong magnet covered with iron filings! OK, that in itself is pretty interesting, because we spent a good while pondering the physics of how to remove iron filings from a strong magnet! But I recommend trying to keep the magnets in their bags, because even though we came up with lots of nifty ideas, our magnets are still, to this day, covered with iron filings.

Step 1: Sweep your magnet through the sand and pick up iron-rich sand.


Step 1 if you accidentally drop your strong magnet directly into the sand. (Oops!)

Step 2: Put your magnet and bag into another bag. Pull the magnet out and the sand will drop into the bottom of the second bag.

Step 1, using the bag around the magnet

Step 2, using the bag around the magnet

Step 3: Repeat until you have a bag of sandy iron filings.


Step 2, assuming you have forgotten about keeping your magnet in the bag and instead dropped it directly into the sand.

Step 4: Repeat the attract and drop sequence with another bag or container so that you can further refine your iron filings and filter out sand.

My husband then recommended that we follow these instructions to create a “magnetorheological fluid.” That was pretty interesting, as well, though not quite as satisfying as the sifting process.

Posted in Homeschooling, Parenting.

One Response

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  1. gasstationwithoutpumps says

    What you get from the beach is not iron filings, but magnetite grains. They work just as well for plotting magnetic fields, but they’re not the same thing. Not all beaches will have magnetite in the sand.

    You can buy iron filings by the pound for about $6–$14 a pound.

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