Number 28: Homemade Magnetic Slime

Fancy making some magnetic putty? There have been a few videos of the stuff doing the rounds on Youtube and I thought it  would be cool to see if I could make some of this fabulous stuff from scratch. Mines a bit more like slimes so it slithers and slides towards magnets like this..

And it consumes magnets like this...

(3 minutes compressed into 8 seconds with the help of imotion app.)

You’ll need:

• A large bottle of PVA Glue
• Borax (some supermarkets or hardware stores stock this, or get it online)
• Black iron oxide (its used in cosmetics and tattoo inks so its harmless)
• Zip lock freezer bag
• Neodymium magnets
• Some plastic cups.

Safety: 

• Borax is toxic in large amounts, so don’t swallow it. And wash your hands after handling the slime.
• The neodymium magnets are VERY strong. They can shatter if they fly towards each other and will pinch if you trap your skin between them. They should only be handled by a responsible adult. Be very careful with them and follow the safety instructions on the packet. 
• AND unless you want to see an adult explode DON'T get the slime stuck in the carpet!

What to do:

1. Dissolve 1/2tsp of borax in 1/2 a cup of water (its not very soluble so don’t worry if some of it doesn’t dissolve)
   
   
   
2. Pour out 1/4 of a cup of PVA into a cup, add the same amount of water.
3. Add 4 teaspoons of iron oxide to the PVA/water and mix it all together. The iron oxide is quite a fine powder and can make quite a mess so be careful.
   
   
   
4. Pour the PVA/iron oxide mix into the zip lock bag.
   
   
   
5. Add the borax solution to the zip lock bag. Flatten the bag so there isn’t any air in it and then zip it up.
   
   
   
6. Massage the contents of the bag. The liquid mix will slowly turn to a black slime. After 5-10 minutes you should be able to take it out of the bag. If its still quite sticky then leave it in the bag for another 5-10 minutes.
   
   
   
7. Once the slime is ready put in on a plate and start experimenting with the magnet. You could try rolling a small bit of slime into a sausage shape and then putting the magnet near it or stick the magnet in the middle of the goo. Have fun!
8. If you want to try some of those time-lapse videos download imotion for Apple or Android. And why not upload it to Youtube and then post the link in the comments below.

What’s going on:

First how does the liquid mixture turn into slime? Well, the PVA glue is made of long thin molecules and together they make a thick liquid. The borax connects the PVA molecules together making a network of connected molecules, which resembles a 3D network, turning it from a pourable liquid in a putty. 

Meanwhile the iron oxide* particles have magnetic properties which makes them align  in the magnetic field of the nearby magnet. Then they are drawn to the magnet, dragging the slime with them.

If you are feeling lazy you can buy some ready made putty (but where’s the fun in that). And besides if you make it yourself you can muck around with the PVA to water ratio to make it more or less runny. More water makes it more slime-like, more PVA makes for a firmer putty.

And if you just want some classic slime then leave out the iron oxide and add some food colouring instead.

* The most common form of iron oxide is rust with a chemical formula of Fe₂O₃. Black iron oxide is Fe₃O₄.