Make a wicked cool catapult that shoots water balloons really well without them exploding right away! You can buy water balloon shooters in stores, but they never work well and explode the water balloon as soon as you let go.
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Step 1: Gather Materials
You will need an old towel, or some sort of rag that you can cut up. You will also need a length of surgical tubing, exercise tubing will work here as well. Lastly, you will need two small scraps of wood and some duct tape. You will also need scissors to cut the rag.
Step 2: Cut the Pattern for the Rag
The rag will become the pocket for the water balloon. It should be cut in a big "+" pattern. So, make a big 14" by 14" (it doesn't need to be perfect) square and cut out 3" by 3" pieces from the corners. You will want two of the tabs to be able to fold over the wood, so plan accordingly.
Step 3: Put It Together
Lay a piece of wood on one of the tabs. Then fold the rag over the wood and wrap the duct tape around it so the wood is stuck inside. Repeat for the opposite side and the other piece of wood.
Next, lay out the surgical tubing so that it runs over one of the other two tabs. Then curve it 180 degrees so that it runs down the other side of the rag. Once again, tape the rag over the tubing. Make sure you don't actually tape the tubing so that the pocket can slide freely up and down the tubing. Tape all of the corners and seams to reinforce them. You can not have to much tape on this project.
Step 4: Try It Out
Fill up some water balloons. Then, tie the ends of the tubing (they should both be on the same side) to a tree, pole, or anything else that is secured to the ground. You could also have a friend hold the ends. Next, have a friend hold the other side of the catapult, if you have a sturdy object close by, then you can attach it to that. Otherwise, the friend will do fine.
Next, set the balloon in the pocket and pull back on the handles of the pocket. Pull back as far as you can and let go! The balloon should fly pretty far. For best results, shoot the balloon at a 45 degree angle. If done right, the balloon shouldn't break and should fly pretty far.
For a better pocket, you can sew all of the seams with a heavy-duty zig-zag pattern. That will hold better and be more waterproof than duct tape, but the duct tape is much easier and quicker.