No leak plastic bag!
We had seen this experiment in one of Lucas’ science books (Science and Stuff by Orbax and Pepper – highly recommend it! These guys are great, we’ve seen their show. Buy the book here). We then saw the experiment on RTE Home School Hub and Lucas wanted to try it out. All you need is a ziploc plastic bag and some sharp, long pencils.
You fill the bag with water and seal it. You then get the pencils and pierce the plastic with them, one at a time, pushing each pencil through the bag and out the other side. We used five pencils, we probably could have added a few more. Despite the holes pierced in the bag no water leaks (unless of course you remove the pencils – so watch out a the end!).
We read a little about the science behind this experiment in the book mentioned above. Plastic is made up of polymers which are like long chains. When the pencils pierce the plastic the chains don’t break but rather they are pushed aside and make room for the pencils, hence no leaks.