Magnetic slime is a type of slime that has magnetic properties due to one ingredient — black iron oxide powder. The slime takes less than 30 minutes to make, requires only a few ingredients, and it’s an exciting way to spend time with kids and teach science.
Magnetic Slime Ingredients and Materials
To make magnetic slime at home, only a few simple ingredients and tools are needed:
- ½ cup PVA white school glue (e.g. Elmer’s glue)
- ½ tsp Borax detergent
- ½ cup black iron oxide powder
- 1 cup water
- 3 tbsp glow-in-the-dark paint (optional)
- 2 bowls for mixing ingredients
- Liquid and dry measuring cups and spoons
- 1 neodymium magnet
PVA white school glue can be found in any stationery shop, and any brand of white glue will work for this project.
Borax can be purchased in any large grocery store. Borax should only be handled by adults because it can irritate the skin and eyes if handled incorrectly.
Black iron oxide and neodymium magnets can be found online on Amazon or at large convenience stores in the US.
Neodymium magnets come in various shapes and sizes. A small cube shape works best for playing with magnetic slime.
How to Make Magnetic Slime (Step-by-Step)
This is an easy magnetic slime recipe that only requires a few simple steps:
Step One: Make the Glue Mixture
Using a liquid measuring cup, measure ½ cup PVA white school glue and ½ cup water. Pour both into a bowl and mix together until they’re fully combined.
Customize your slime mixture by adding glow-in-the-dark paint.
Step Two: Make the Borax Mixture
In a separate bowl, mix ½ teaspoon of Borax with ½ cup of water.
Borax detergent holds the slime together and gives a slimy feel. It’s best to let an adult handle this step to protect children from getting detergent on their skin or in their eyes. Once Borax is mixed with water, it loses its dangerous qualities.
Step Three: Combine the Mixtures
Pour the Borax mixture into the bowl with the glue mixture and combine together using a spoon until the mixture resembles firm slime and the water separates. Pour the excess water down the drain.
Borax powder breaks down into borate ions in water, creating a chemical reaction with the glue that turns the mixture into thick and stretchy slime.
Step Four: Add Black Iron Oxide
Measure ½ cup of iron oxide powder and carefully pour it into the bowl with the slime. Knead the slime carefully with your hands until it’s smooth and a uniform, dark gray color. Add more black iron powder if the slime isn’t dark enough.
Step Five: Test the Magnetic Slime
There are many ways to play with magnetic slime. Hold the neodymium magnet close to the slime, and watch the thin, fascinating slime tentacles reach towards the magnet.
Move the magnet around the slime’s surface to make the slime tentacles dance. Set the neodymium magnet on top of the slime and watch the magnet disappear.
Magnetic Slime Tips
Here are several ways to make creating magnetic slime even more exciting and safe:
Handle Iron Oxide Gently
Iron oxide powder is generally safe to handle, but it’s messy, can cause stains, and is harmful if inhaled. Handle this ingredient gently so its tiny particles don’t contaminate the air. Iron oxide is better handled by adults.
Get the Right Slime Texture
When making slime using Borax, completely dissolve the Borax in the water to limit clumps — around 30 seconds of mixing.
If the slime is too sticky, add another tablespoon of iron oxide powder and knead for an additional three to five minutes.
If the slime is too tough (feels rubbery and doesn’t stretch), add 1 more tablespoon of white glue and knead the mixture gently.
When the slime hardens after several days, soften it by adding one or two drops of antibacterial gel or 1 teaspoon of regular hand lotion to re-soften it.
Use the Right Magnet
Use a neodymium magnet to play with magnetic slime because regular magnets aren’t strong enough to make the slime react.
Neodymium magnets are the strongest type of magnet, and they can damage electronics. Keep the magnet away from phones, laptops, and other technology.
Do Not Involve Children Under Five Years of Age
This project is best for children five years and older and isn’t suitable for young children who put things in their mouths. Neodymium magnets are dangerous if swallowed, and Borax and iron oxide powder can also threaten the health of young kids if swallowed or mishandled.
Make Clean-Up Easy
Making magnetic slime can be messy because the powder ingredients are easy to spill and can contaminate the air.
Work in a well-vented room, handle powder ingredients gently, and use warm water mixed with liquid soap to easily clean ingredients and slime from surfaces and the tools used to make this recipe.
Making Magnetic Slime Without Borax
Borax is a detergent powder, which means it’s made of dangerous chemicals that can burn skin and hurt the throat and lungs if spilled or inhaled. Borax should be handled by adults, always with extra care.
To make magnetic slime without Borax, substitute Borax with ½ cup liquid starch and halve the water in this recipe. Liquid starch can be purchased from any grocery store.
Substituting Borax with liquid starch keeps the powder ingredients from contaminating the air.
Step One: Make the Glue Mixture
Use a spoon to mix together ½ cup of PVA white glue and ½ cup of water in a bowl.
Step Two: Mix Liquid Starch With Iron Oxide
Measure ½ cup each of liquid starch and iron oxide powder and use a spoon to mix them together in a separate bowl. Stir until the mixture is a consistent dark gray color.
Step Three: Combine the Mixtures
Pour the glue mixture into the bowl with starch and iron oxide, and mix together with a spoon or your gloved hands until the mixture turns into a firm, stretchy slime.
If your slime has too much liquid, add more starch, and if it’s too tough, add more glue.
Step Four: Test the Slime
Use the neodymium magnet to play with the magnetic slime. Magnetic slime made with liquid starch can also be played with just like slime made with Borax.
Here are a few other fun slime projects we’ve been trying out:
(Photography ©A Subtle Revelry by Ashlyn Savannah Photo).
