Magnetic Slime Recipe

What you’ll learn:

What magnetic fields look like, and the chemistry of magnetic slime.

Key takeaways:

To see magnetic fields we need to trap small magnetic particles with a magnet in some type of fluid.

Magnetic fields are really fun to play with. Kids love them as evidenced by their affinity to the ball and stick magnets, or the magnetic tile building toys.

We recently made a DIY magnetic field viewer using just a few ingredients. The magnetic field viewer is cool because you can see the field lines forming in the oil.

When you want to try a new magnet you just take the old one away and poof!

The magnetic field lines vanish from the viewer, dropping the iron filings to the bottom of the viewer.

But what if you wanted to preserve the magnetic field lines to show students, or to compare the field lines of various magnets? Our DIY magnetic field viewer wouldn’t work so well in that type of a situation.

Instead, to keep magnetic field lines stable after you take away the magnet, you can create magnetic slime. Our magnetic slime uses clear slime as a base and adds in iron filings that will eventually form the magnetic field lines.

This is far different from many other types of magnetic goo you might have encountered which often are black and opaque.

What is the benefit of a clear base for magnetic slime? Well, because you will be able to see the magnetic field lines! I have yet to see a magnetic goo that can do this simply because of the opacity of everything on the market. 

Project Ingredients:

• Clear slime (Clear glue, baking soda, contact solution with boric acid, and water)
• Iron filings
• Magnets

How to make magnetic slime

1. Mix up a batch of clear slime
2. Add 1 teaspoon of iron filings and slowly knead into the slime
3. If you just want magnetic slime you can add colors, glitter, shimmer etc. If you want to be able to see the magnetic field lines in your slime keep it clear!
4. Go to the next part to learn how to see the magnetic field lines in your magnetic goo

How to make magnetic field lines in your magnetic slime

1. Flatten our your slime into a small rectangle.
2. Wrap your magnetic slime in plastic wrap.
3. Place a strong magnet on top of your magnetic goo and watch the field lines form
4. After a minute or two remove the magnet and hold the slime up to the light.

The beauty of using slime to see the magnetic field lines is that the field lines will stay put when you remove the magnet. Why? Because the iron filings are stuck in the super thick magnetic goo. When a magnet is placed nearby it exhibits a force on the iron filings and aligns them, and pulls them closer to the magnet. However, when you remove that force they are just plain stuck.

To see new field lines in your magnetic slime you will need to knead the magnetic goo once again. Another fun project with this magnetic slime is to stick some googly eyes on it and have a magnet eating monster chomp down!

Congratulations are in order!

A big round of applause to this scientist who used hard work, planning, good note taking, and a lot of learning to turn our magnetic field line slime into a blue 1st place ribbion in her division and a gold medal for her entire grade in observation and investigation!