Gary Stedman (stedmang@CADVISION.COM)
Fri, 30 Jun 1995 18:42:14 -0500
I've never tried the water rockets that have been posted, but we'd had
great success with YOP rockets. (YOP is a yogurt drink that comes in a
small plastic bottles with tight fitting caps). We've had a lot of fun
launching these rockets in our group. (Sorry Rod - these rockets aren't big
enough to tie cubs to!!!!)
How to Build and Launch a Yop-Rocket
To Build a rocket
1) Get a YOP bottle from the nearest store. (YOP is a yogurt drink and it
can be purchased almost everywhere you can buy yogurt)
2) Clean off all the labels and wash it out well
3) Decorate it anyway you want (put wings on it, colour the bottle, etc)
To Launch a rocket
NOTE: STAND BACK WHEN LAUNCHING THIS ROCKET - It goes up fast and strong
1) Put some vinegar into the bottle (About 1 1/2 to 2 inches is enough)
2) Wrap a tablespoon of baking soda inside a single sheet of toilet paper.
The rocket works better if you only use a single layer of toilet paper
3) Put the wrapped baking soda into the cap of the YOP bottle The wrapped
baking soda should be big enough to just fit inside the depression in the
***** Steps 4,5 and 6 have to be done quickly *****
4) Pop the cap back into the bottle The tighter the better. If the baking
soda is the proper size, it won't fall into the vinegar when you put the
5) Put the bottle on the ground with the cap side down
6) STAND BACK!!!!!!!!!!!!!!!!!
7) Clean up the remains of the toilet paper
How does it work?
The baking soda and the vinegar combine to form carbon-dioxide gas. This
gas builds pressure inside the YOP bottle until the seal on the cap can no
longer hold. At that time the cap pops off and the escaping carbon-dioxide
pushes the rocket up into the air.
Wrapping the baking soda in the toilet paper slows down the reaction
because the vinegar has to soak through the paper to get to the baking
soda. This gives you time to put the rocket down and stand back.
KAA (Gary Stedman), 75th Midnapore Scout Group, Calgary Alberta Canada
Terry Howerton Sakima Group, Inc. SCOUTER Magazine Kansas City