How to Make Magnetic Slime
In this science experiment, we walk through how to make slime that reacts to a magnetic field. Using school glue, borax, iron filings, and water, we create a ferromagnetic substance that appears to swallow a neodymium magnet whole! To use this experiment for a magnetic science fair project, consider questions like: How does the amount of iron in the slime change the interaction of the slime and the magnet? Are some magnets stronger than others?
1. Place 120 ml (½ cup) of PVA glue (Elmer’s School Glue) in a 500 ml container.
2. Add 120 ml (½ cup) of warm water to the same container.
3. Sir this solution until it is mixed to an even consistency and set this solution to the side to be used in a later step. This is solution number 1.
4. In a second 500 ml container add 240 ml (1 cup) of warm water.
5. Add 5 ml (1 tsp) of borax powder to the container and stir until the borax powder is completely dissolved. This is solution number 2.
6. Slowly add small amounts (10 drops at a time) of the borax mixture (solution 2) to the glue mixture (solution 1) until it thickens into slime. Make sure to continue stirring the glue mixture (solution 1) as you are adding the borax mixture (solution 2). Add about ten drops and then stir these drop into the mixture completely before adding ten more drops. Stop once the mixture has turned into a slime consistency.
Note: If too much borax solution is added the slime will be very stiff and not very slimey, so make sure to add solution 2 slowly and be careful not to add too much. If you end up adding too much borax solution and your slime ends up being stiff and rigid make more glue and water solution and fold the slime in this solution until it loosens and becomes slimy (This can take anywhere from five minutes to two hours depending on how much borax solution was added so it is sometimes easier to start over if your slime is extremely hard and thick.)
7. Take your slime and fold it 20-30 times to make sure all the ingredients and mixed well.
8. Add 60 - 160 grams (2 Tbsp) of iron filings to the slime and mix it together by folding the slime 10-20 times.
9. Now you can use a neodymium magnet to manipulate the slime. The iron filings are attracted to the neodymium magnet and because they are mixed into the slime the entire blob can be manipulated via a strong magnetic field.
Note: As you play with your slime water will evaporate and need to be replace by dipping the slime in warm water and then folding the water on the surface of the slime into the slime itself.
Elmers School Glue (PVA Glue)
magnetic iron filings
Need supplies for this experiment?
See this list of materials on Amazon.