Fun Friday – making slime!

Here is a fun science experiment that all kids love….. and no matter how many times a child may have done this one, they are always happy to do it again!


You will need….

  • two small bowls or cups
  • PVA glue (white or clear is fine)
  • water
  • food colouring (optional)
  • Borax* powder.

*You can pick up the borax powder in your local chemist (See note below)

What you do… 

  • To the first bowl add half a cup of water and half a cup of PVA glue and mix well.
  • If you want to make coloured slime add a few drops of food colouring and mix this in well.
  • In the other bowl add one teaspoon of borax powder to one cup of water and mix well until all the powder is dissolved!
  • Now for the fun bit… pour the borax solution into the PVA/water mix and mix, mix, mix!!! YOU HAVE JUST MADE SLIME!


This experiment is as fun as it looks!

If you want to keep your slime just pop it into a Zip-lock bag and seal it and it will be ready for you next time you want some slimey fun!

So what is happening?…

Congratulation… you have just made a polymer!! In simple terms a polymer is a substance made up of lots of molecules arranged in long chains.  If you imagine that the glue is like cooked spaghetti, it slides and slips around the place quite easily.  When we add the borax to the glue it causes some of the molecules in the glue to stick together making the glue more rubbery and less liquid!  Imagine if you took those strands of spaghetti and tied them together in places, the strands would not be able to slip and slide around nearly as much! The borax and glue mixture is just like your knotted spaghetti!

*Where can I get Borax powder?

In Ireland you need to buy Borax powder in a pharmacy.  The production is a little erratic and the larger volumes are no longer available!  You should be able to get this 100g tub in any pharmacy and it costs about €2.25.

UPDATE 2017: Borax powder is no longer as readily available in Ireland.  here is one alternative, using very simple ingredients… check out this post on how to make silly putty.

Or check out our Ultimate Slime Guide for lots of fantastic slime recipes using contact lens solution or laundry detergent.


Check out next week’s Fun Friday post for more slime recipes to try at home!


Science blogger and writer; Owner of Dr. How's Science Wows; Mother of three junior scientists who have taught me that to be a great scientist you need to look at life through the eyes of a child!

6 thoughts on “Fun Friday – making slime!

  • July 5, 2017 at 9:53 pm

    We use contact lens solution that has boric acid in the ingredients. Boots own brand works. The small bottle is around 6 euro but has lots. 1 spoon of lens solution, 2 spoons pva, 1 spoon of paint and a pinch of baking soda.

    • July 6, 2017 at 12:38 pm

      Hi Sinéad, thanks for sharing that. We have been testing a number of alternative slime recipes, including ones with contact lense solution, but we haven’t tried the boots one, so I will check that out!

  • March 26, 2017 at 10:02 pm

    Borax is impossible to get in ireland, please dont waste anytime trying to get it. For years on and off i cannot get it.

    • March 27, 2017 at 10:29 am

      Hi Evelyn, as you can see, this is an older post and borax was a lot easier to get in chemists at the time. I have asked locally and I am told it is not often available anymore. I am planning to test other borax containing materials that are available, such as eye drops and contact lens solutions and I will post new recipes here when I have them ready to share.

      There are other alternatives too, like the silly putty I posted about recently… and some other options that we are currently testing.

  • October 7, 2013 at 7:05 am

    I have been looking for Borax … do you have a photo of the box/packaging it comes in.
    I might have to get mine to make their slime. We made homemade face paints over the weekend using Cornflour, moisturiser and Beetroot and Turmeric for colour. … it was messy but lovely and so much softer and kinder to their skin than the shop bought stuff. If you have a photo of the Borax can you tweet it to me? I use to use it all the time in the US for his ‘Chef whites’ …. Are you headed up to the Blog Awards on Sat?

    • October 7, 2013 at 8:21 am

      That homemade face paint sounds fab… please send a link if you share sometime! I will tweet you a photo of the borax and will add to this post. Won’t be at the blog awards although would love to meet some wonderful people who I know will be there! Enjoy!

Comments are closed.