Did you know that it’s possible to make slime that is magnetic? Magnetic slime has iron in it and is attracted to a strong magnet. It is super stretchy and so much fun. When you hold a magnet near the slime, it oozes toward it, and the slime will “swallow” up a magnet if you let it go! SO COOL.
Magnetic slime is easy to make with our 3 ingredient recipe!
This post was originally written in March 2014 and updated in April 2019. Our updated recipe is easier to follow and is much less messy! Slime has a bad reputation for being messy, and you may be afraid of a “slime fail.” I can assure you, however, that this project will be fun and successful! I do recommend reading the instructions carefully, and you’ll want to try out this project first before doing it with a group.
What can magnetic slime do?
Magnetic slime is really fun to play with on its own. It stretches and squishes. If you hold it up, it oozes down to the floor in a long strand! Adding the element of magnet play makes it even more awesome. This is a great project to put on your to-do list for a rainy day, spring break, or summer! It would also make a great group activity for a science club or scouting group.
There’s just something about watching a liquid move without touching it… So fascinating!
You can get the slime to move faster if you let the magnet touch it. It’s also cool to feel the magnet stick to the slime.
We also had fun putting the magnet on top of the slime and watching the slime swallow it up!
Supplies Needed for Making Magnetic Slime
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- Liquid starch – We used Sta-flo Liquid Starch.
- Elmer’s glue – we used white glue, but the clear might also look cool! This is PVA glue.
- Iron Oxide powder
- A bowl for mixing – it does wash out.
- Plastic spoons for stirring
- A 1/4 cup measuring cup
- A 1 Tablespoon measuring spoon
- A neodymium (rare earth) magnet – A regular magnet won’t be strong enough. Here’s a set on Amazon with two Neodymium Barr Magnets. We ordered ours awhile back, but our Amazon history says we used this link, although the magnets look slightly different.
How to Make Magnetic Slime:
Step 1: Pour 1/4 cup of white PVA glue into your mixing bowl. You may have to use the spoon to scrape all the glue out of the measuring cup.
Step 2: Add 2 Tablespoons of iron oxide powder. Stir well.
You’ll be expecting the mixture to look solid black, like my photo of the slime above. However, it will look more like Oreo cookie crumbs! Don’t worry – it will look solid black in a minute.
Step 3: Pour in 1/8 cup of liquid starch.
Step 4: Stir the glue and starch mixture really well to make sure that it’s all mixed. As soon as you begin to stir, the starch will react with the glue and the slime will start to form.
I ended up with a little bit too much starch. The way I could tell is that there was some unmixed starch in the bowl and on the slime after I had stirred it well. To fix this, I rinsed the slime for just a few seconds under cold water.
Step 5: Knead the slime with your hands.
This is how the slime looked after a quick rinse and a little bit of kneading. I find that it helps to wash my hands after kneading the slime and before playing with it. This helps to make the slime less sticky.
- If your slime is too sticky (glue-y), knead in a tiny bit more starch. If it’s too stringy, knead in a little more glue.
- If your slime does not respond to your magnet, the problem is the strength of your magnet. We ordered some new cylinder neodymium magnets which did not turn out to be strong enough!
Here are a couple more important notes:
- Neodymium magnets are extremely strong! Fingers can easily get pinched when trying to separate the magnets. Be sure to keep the magnets away from cell phones, computer, and other electronics. If you order the smaller disc magnets, make sure that no one puts them in their mouth – these would be very dangerous if swallowed. Overall, this is not a project for kids who still put things in their mouths.
- Iron oxide powder is not good to breathe. This is why we mixed our iron in with the glue. I have seen some recipes on the internet that recommend kneading the iron oxide powder into the finished slime. We tried that approach, and besides being super messy, I think it’s much more likely to stir up the iron oxide dust.
If making magnetic slime seems like too much of a hassle, you can actually purchase magnetic silly putty – Crazy Aaron’s Thinking Putty which comes with a magnet and does the same thing. (Although judging by the reviews, I think the homemade slime responds better to the magnet!)