Its really easy and simple. And also really awesome & cold!
Step 1: Gather Supplies.
- a balloon
- a knife
Step 2: Fill Your Balloon With Water.
How much water you're supposed to use depends on how big you want your sphere.
Step 3: Tie Your Balloon.
Just make sure you let out all the air before you tie it.
Step 4: Now Put It Into the Freezer.
How long should you keep it there? I'd say overnight would be long enough if you want it frozen completely. It freezes from the outside in, so if you want a hollow sphere you might freeze it for about 4 or 5 hours and then punch a hole in the outer ice and drain the water inside.
Step 5: Take It Out of the Freezer.
Step 6: Cut the Balloon and Take It Off the Ice.
Step 7: And Now You Have Your Ice Sphere!
Step 8: Try Out Different Ways to Freeze the Balloons.
- Adding food colourant
- Placing it in a strange container
- Putting objects into it before adding water (marbles, leaves, etc.)
P.S. Its also quite fun to smash the ice spheres!