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Water balloon shells

Written by WaterWolf
Last updated on 2008-03-07

This is the seventh version of my new line of WB-Shells, christened the V7 Snake-Eye for its resemblance to the Mark 81 Snakeye Bomb.

This project is the result of about a year of tinkering with shell designs and I have reached the point where it has gotten so good that its very hard to improve, but I would appreciate any further comments.

The first section, the "Flare", is built out of the bottom of an empty, 1-lb sour-cream container, which has been cut to fit the 3-inch barrel with an impressively air-tight seal.

Container before cutting.
Container before cutting.

You can achieve this easily by placing the container bottom down into a 3-inch PVC barrel, then using a pen to mark a circle flush with the PVC pipe. Cut along the line. Now you have an almost perfectly air-tight piece. Some extra trimming may be necessary, but this should get you very close.

Container after cutting.
Container after cutting.

The second part, the "Body", is a section of Pringles can that has been cut in several ways.

First, slice off the rim that holds on the Pringles can. Wrap it all in just one layer of duck tape, no more. We are not trying to get it air tight here, the tape is just to strengthen it. Slide the Pringles can down a 3-inch pipe, it should fall in easily.

Insert the Flare piece, bottom first, into the open end of the Pringles can, it will go in a little way and then stop. Measure 5 inches from the outer edge of the Flare up the Pringles can. At the 5 inch point, cut the Pringles can. Wrap one more layer of duck tape around the Pringles can piece and some of the exposed Flare to hold them together. Try not to put any duck tape on the actual rim of the Flare. Cut some off if necessary.

Cut four vertical slits down the sides of the Pringles can - not all the way down, just to the point where the flare is inside the shell. Flex these flaps out once and then back to their regular position.

Insert one balloon. It should not project out further than the front edge of the Pringles can, and if it does, you are using too large a warhead.

Finished shell without warhead
Finished shell without warhead.

Finished shell with warhead
Finished Shell with warhead.

When the round is slid down the barrel, the sides of the nose will be pushed together by the inside of the barrel and the balloon will be held between them. When the launcher is fired, the round flies out at maximum possible speed, due to the air-tight but low friction Flare. As it hits still air outside the barrel, the cut sections on the Body deploy, releasing the balloon to continue on its flight without slowing, while the fins of the can catch air like a drag chute and cause the shell to drop to the ground fairly close to the launch-site.

This shell has the highest air-efficiency level I've ever seen, while at the same time staying cheap and easy to use. The more efficient a shell is, the farther it will be able to send a balloon with the same amount of air-power.

The previous champion for air-efficient WB-Shells in my opinion was a Pringles can wrapped in several layers of duck tape, which I had noticed tended to cause a significant amount of friction inside the barrel. And so, after a lot of work, I've built my own low friction but air-tight design. The Pringles can does make up a portion of the shell, but it is only being used to hold the balloon and prevent rupture or friction.

After performing many tests, I have found that the Snake-Eye has the Pringle's method beat on several counts:

  • It has approximately 15% higher efficiency.
  • About two shells can be made out of a single Pringles can, instead of just one.
  • Balloons are less likely to detonate inside the barrel when firing.
  • The Snake-Eye has a lower drop-off distance. (Making retrieval faster.)
  • They weigh less and do not include any metal parts, such as the Pringle's metal bottom. (Which could be potentially painful if struck at close-range.)
  • It is shorter in length, making it easier to transport and takes up less space in the barrel. (This is also highly relevant for one of my more important "Coming soon" items)

The only problem I've found with the V7 Snake-Eye is that it is so air tight that the pressure behind it builds up and makes it difficult to push down the barrel. This however can be solved by either cutting a small notch in the flare, or by installing my (***CLASSIFIED***) piece that will soon be unveiled.

The other slight issue (though the Pringle's method has this too) is that the body can become somewhat soggy when it gets wet.
If you are able to however, then you can use a plastic tennis-ball container for the body, instead of a Pringle's-can. Follow the same instructions, but with the different material. The one problem with this is that buying that many cans could be expensive ($3.00 each for me), but if you can find a cheap source of these (such as a friend who plays tennis, or a fitness center with a tennis-court) then I would highly recomend building the Snake-Eyes with the plastic containers, as they are water proof, harder to damage and seem to cause even less friction with the sides of the barrel, making them more efficient to load and fire.

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