This has to be one of the coolest slime you will ever make. If you want to learn how to make magnetic slime, this is about as simple as it get. All you need is liquid starch and the secret, magnetic ingredient for a very exciting science demonstration. Slime is an awesome science and sensory play activity for kids.

HOW TO MAKE MAGNETIC SLIME WITH IRON OXIDE POWDER

Learn how to make magnetic slime with black iron oxide powder and liquid starch. Use our classic Elmer's glue slime recipe to make this cool magnetic science demonstration. Adding iron oxide powder to homemade slime produces a super strong magnetic slime that works well with neodymium magnets for amazing results. Slime is a great science demonstration for kids chemistry. Adding magnets also turns it into a cool physics activity. Making slime is also an amazing sensory tool for kids.

SLIME AND SCIENCE

We love making homemade slime because it’s just so easy to do, and we have perfected a handful of awesome slime recipes that anyone can make easily at home or in the classroom.

Now it’s time to step it up a notch and learn how to make magnetic slime! It’s truly an ultra-cool slime that my son can’t get enough of playing with whenever we make it. Plus neodymium magnets are super neat to use too.

A while back we made a very simple magnet slime by adding contents of our favorite magnet kit to our regular white glue homemade slime recipe. That was super fun when my son was younger, but we were ready to step it up a notch.

No more having to print out a WHOLE blog post for just one recipe!

Get our basic slime recipes in an easy to print format so you can knock out the activities!

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Make homemade magnetic slime recipe

HOW DO YOU MAKE A MAGNETIC SLIME?

There are two very important ingredients needed to make and enjoy this super-strong magnetic slime recipe and that is iron oxide powder and a neodymium magnet.

You can also use iron filings, but we chose the powder after we did a simple search on Amazon for what we wanted. The powder we purchased, although pricey, came well packaged, and will make many batches of slime for us.

A neodymium magnet is also known as a rare earth magnet which is actually pretty different than the regular magnets you are probably accustomed too. A rare-earth magnet has a much stronger force field and is made of different materials which is why it works with the iron oxide powder or fillings over a traditional magnet. You can read a little more about these magnets here.

We tested our regular magnetic wand on this iron oxide powder slime and nothing happened! Don’t you always have to check and see for yourself. We purchased both a bar shape and cube shape neodymium magnet, but the cube shape was the most fun.

MORE FUN WITH MAGNETS

Neodymium magnets and magnetic slime recipe for kids science

Below you can see our cube-shaped neodymium magnet engulfed by the magnetic slime. It’s very cool how the slime will complete crawl around the magnet and bury it inside.

Magnetic slime recipe

MAGNETIC SLIME RECIPE

SUPPLIES:

  • 1/2 cup black iron oxide powder
  • 1/2 cup PVA White School Glue
  • 1/2 cup liquid starch
  • 1/2 cup water
  • Measuring Cups, Bowl, Spoon or Craft Sticks
  • Neodymium Magnets (our favorite is the cube shape)

Magnetic slime recipes supplies with liquid starch and black iron oxide powder

HOW TO MAKE MAGNETIC SLIME

NOTE: Adult assistance required! This slime can be easily made ahead of time and used for many days afterward. The mixing process can get a little messy and should not be done by younger kids.

STEP 1: Pour 1/2 cup of glue into a bowl.

STEP 2: Add 1/2 cup of water to the glue and stir to combine.

Black iron oxide powder for making magnetic slime

STEP 3: Add a 1/2 cup of the iron oxide powder and stir to combine. This is probably best left for adults to do as the powder can get everywhere quickly.

We did not find that any of the particles flew around but I would not recommend spending to much time inhaling the open bag.

Make magnetic slime with Elmer's glue slime recipe

You will notice that this mixture is more grey to start out with, but the end result will be a very black and glossy color.

Mixing up magnetic slime recipe

STEP 4: Measure out a 1/2 cup of liquid starch and add to the glue/water/iron oxide powder mixture.

Homemade magnetic slime using liquid starch and iron oxide powder

STEP 5: Stir! Your slime will start to come together immediately but just keep stirring.

How to make magnetic slime

It will begin to darken so don’t worry if it still appears gray. There will be liquid leftover from this slime in your bowl. Transfer your slime to a clean, dry container. I would suggest letting it set up for 5-10 mins.

Make magnetic slime with classic homemade slime recipe

Time to have fun and test out your magnetic slime! Grab your magnets and see what happens.

THE SCIENCE BEHIND OUR SLIME RECIPE

We always like to include a bit of homemade slime science around here!  Slime is an excellent chemistry demonstration and kids love it too.   Mixtures, substances, polymers, cross-linking, states of matter, elasticity, and viscosity are just a few of the science concepts that can be explored with homemade slime!

What’s slime science all about?  The borate ions in the slime activators (sodium borate, borax powder, or boric acid) mix with the PVA (polyvinyl acetate) glue and form this cool stretchy substance. This is called cross-linking!

The glue is a polymer and is made up of long, repeating, and identical strands or molecules. These molecules flow past one another keeping the glue in a liquid state. Until…

You add the borate ions to the mixture,  and it then starts to connect these long strands together. They begin to tangle and mix until the substance is less like the liquid you started with and thicker and rubbery like slime! Slime is a polymer.

Picture the difference between wet spaghetti and leftover spaghetti the next day. As the slime forms, the tangled molecule strands are much like the clump of spaghetti!

Is slime a liquid or solid?

We call it a Non-Newtonian fluid because it’s a little bit of both!  Experiment with making the slime more or less viscous with varying amounts of foam beads. Can you change the density?

Did you know that slime aligns with the Next Generation Science Standards (NGSS)? 

It does and you can use slime making to explore states of matter and its interactions. Find out more below…

Make magnetic slime to use with neodymium magnets for chemistry and physics demonstrations

What can you do with magnetic slime? We love watching the magnet get swallowed up by the slime. It never gets old.

If you want a truly intriguing science project and science recipe then you totally want to learn how to make magnetic slime with your kids. It’s a fascinating experience, and there is so much to learn.

If you happen to get some magnetic slime on clothing? No worries! Check out our tips for how to get slime off clothes and hair.

Learn how to make magnetic slime to explore magnetism and polymers science

MORE MUST TRY SLIME RECIPES

LEARN HOW TO MAKE MAGNETIC SLIME!

Try more fun slime recipes right here. Click on the link or on the image below.

liquid starch slime homemade recipes

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19 Comments

  1. Thank you so much for publishing this recipe! At my son’s request, we ordered red iron oxide powder (he thought it would look better than black). We just made our first batch of magnetic slime and it is not at all magnetic:(. I have 4 stacked neodymium magnets and nothing happens. It there something different about the black iron oxide powder? Have you tried red?

    Thank you!

  2. I got my answer! Red and black have different t chemical formulas and therefore, different magnetic properties. Must use black like your recipe states.

    Any ideas for what to do with 5lbs of red iron oxide???

  3. I just have a question. I really want to do this with my students but I have a concern about the black color. Does it stain? I did a project with black food color and it was a mess. Just trying to avoid a repeat. This recipe sounds too good not to try.
    I appreciate your time and fun activities.

  4. Love these recipes are super useful for a stall I am running where we are selling slim and putty ! Thank you for these great recipes!

    – RainbowGal1245

  5. We did not have an issue with it staining once it was incorporated. You need to mix gently.

  6. I would like to know how to store the slime. My friend and I just made a batch of it but I haven’t seen anywhere how to store it.

  7. Hello, i don’t live in the US so iron oxide is not wasy to come by. I can only find iron oxide used to color cosmetics. Will this work as well?

  8. I do not believe it will have the same effect unfortunately. However, it’s worth a try for an experiment. Can you not order from Amazon?

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