Mix clean sand and white craft glue to obtain an oatmeal type of consistency (add small spoonfuls of water but no more than two). Clean sand can be obtained from a beach or at a craft store. Blow up a balloon or a beach ball (we had more success with a beach ball as the balloon if too tight can pop while doing this) and rest the tied end into a bowl. Start at the top and pour the liquid and allow to run down. Make sure there are no gaps – you do not want a spider web effect. Dripping is allowed. Allow to dry overnight. Repeat process to create a thick three or four layer effect. Now on the last layer you will watch for it to be almost hard – then you will flip it out over to rest on what used to be the top. You are going to do this to create a flat bottom. Too early this will form in a huge puddle  – too late and it won’t form. Its cheap and that is good because if you mess up try again.