How to Make Magnetic Slime
You really really need to learn how to make your own magnetic slime because oh my goodness! This stuff is absolutely the coolest!! I only just finally got around to ordering some iron oxide powder and magnets and I sincerely wish I had done it sooner. This is a project involving minimal mess, lots of learning and sensory play, and science.
Plus, I was thinking that this would be a super cool gift for a birthday, Christmas, or another holiday. If you know a family that doesn’t want to deal with making the mess, but likes the play part - this would be an ideal gift. It would also work great as a Scout or classroom activity. Guess what my Girl Scouts are going to be doing soon?
Neodymium Magnets
Until I made this recipe and did a little more research, I never truly understood what a neodymium (pronounced like neo-dim-ee-um) magnet is. This slime recipe won’t work with anything other than a very strong magnet. The normal ceramic magnets you find at craft and hardware stores cause barely any movement in this slime (I know because we tried!) But if you put a neodymium magnet up to it - it’s a completely different story.
Neodymium magnets are rare earth magnets that are incredibly strong. When using these magnets with small kids - please be aware of a few things. If the magnets are allowed to snap together and fingers are in the way - the finger in question will get a wicked pinch. I bought long bar-shaped magnets thinking it would be easier to play with them since there is more surface area to grip.
I was right about one thing - the surface area does make a difference. Two of our magnets got too close together and I physically could not separate them. I used the countertop edge to try and break them apart, but I just couldn’t get them apart.
If a small child were to swallow more than one of these - they could potentially stick together in the gut or through the intestinal walls which is a VERY serious issue and would require immediate surgery. You know your kids best - this is definitely not something that a child who still swallows things should be playing with.
Will it Erase My Smartphone or Hard Drive?
I actually worked for a public television station in college in the tape library and one of my jobs was to take old program tapes and use a very large magnet to erase them in preparation for the next night’s recordings. So when I heard that this was a super strong magnet - I assumed that my smartphone and/or computer would be vulnerable if these got too close. But after further research…I think it’s not nearly as big of a deal as I had originally thought. We’re pretty much surrounded by magnets (many of them neodymium!)
For a better explanation - check out this article:
Will a Magnet Destroy Your Smartphone or Hard Drive?
Takeaways:
- This is not a good activity for very young children or kids who still put things in their mouths.
- Having these magnets around the house is not a big deal for your electronics.
Want to learn how to make magnetic slime? Let’s take it step by step.
What You’ll Need
(In the spirit of full disclosure - I have included my affiliate links below. That means that if you purchase these supplies through my links, I receive a small commission at no additional cost to you.)
- 1 Cup water (hot works best)
- 1 tsp Borax
- 1 Tbsp iron oxide powder
- 1 container school glue (4 oz)
- Additional water (4 oz)
- 2 containers (one larger than the other)
- 2 stir sticks (wooden craft sticks or plastic knives work well)
- Neodymium magnet (the link is for the bar I used, but I like this pack of 10 discs as well or you could do individual discs if you didn’t want that many)
A few notes about the magnet shape I chose - I picked this long bar because I thought it would be easier to hold than little circles. Next time - I might add to our stash and get those smaller circles. And for a classroom or scout troop - I would definitely choose the smaller circles (it’s definitely more cost effective.)
Step 1 - Mix Water and Borax
In the smaller one of the containers, mix 1 Cup of hot water and the Borax together until the Borax is completely dissolved. I like to use hot water because the Borax is much easier to dissolve. Careful not to make it too hot though if you’ve got little helpers since you don’t want any burned hands (more explanation coming.) Set your mixture aside.
Step 2 - Mix Water and Glue
In the larger container, pour out the entire bottle of school glue. Once the bottle is empty - fill it up with water (doesn’t have to be hot since the glue dilutes easier than Borax does) and empty the water into the container with the glue. Mix thoroughly until it’s a sort of milky liquid.
Step 3 - Add Iron Oxide to Glue Mixture
In the container with the glue mixture, mix in the 1 Tbsp of iron oxide powder. Since iron oxide powder isn’t a great thing to inhale - this initial part is probably a good part for a grown-up to do. Once the powder is stirred into the liquid, your kiddo can help you stir it in really well.
When you first add it - it looks a bit like cookies and cream ice cream because the powder turns into black dots and doesn’t mix in immediately. But with enough stirring, it blends in fairly well and the mixture will turn to a light gray.
Step 4 - Mix the Two Containers Together
Pour the Borax water mix into the glue/iron oxide powder mix. Stir slowly. The reaction between the two substances will happen immediately. Your glue will go from soupy to goopy right away.
I originally would pour out the extra liquid. But I discovered that I really like the texture of the thinner (more slimy) mixture. So instead of pouring out the liquid - start kneading it. The liquid will sort of float around on the top of the more solid goop, but it can be mushed together.
This is a good step for kids to help with because I guarantee they’ll be dying to get their hands on this wonderful glop. So have them knead the goo until the water absorbs fully. If they tire out before it’s absorbed, just take it over for a few minutes.
Step 5 - PLAY!
This step is the best part - now you get to play with your slime and magnets (either together or separately or both.)
Also check out some videos with the slime in action.