The balloon we used was a 4 foot
diameter weather balloon filled only with hydrogen. We decided not to premix because we
had never used a balloon of this size. Many experiments led up to this successful water
synthesis. In the smaller balloons that I explode in the classroom, I use a candle taped
to a meter stick to initiate the reaction. With this balloon, we had to develop a remote
ignition system. The obvious choice was the system we had already been using for other
remote ignitions. This system consisted of a model rocket ignitor, stereo wire, and a 9V
battery. We decided to try it with a standard balloon first. It was a good thing we did
because it didn't work. The ignitor flared long enough to melt the balloon, but was not
able to also initiate the reaction. We pondered other ideas: flaming arrow (Where would it
land? Too risky. Sorry Dan), methanol soaked string attached to balloon (It works, but the
methanol evaporated quickly among other problems), and black powder fuse (Never tried).
However, as I considered the problem (short burn time) more carefully, a simple idea
struck me and the MegaMatch was born. A MegaMatch is 6 or more matches taped together in a
bundle. Our first experiment was to see if a rocket ignitor could ignite a MegaMatch (it
did). Our second experiment was to see if this would work with a small hydrogen balloon
(it did). The MegaMatch bundle is taped to the balloon and a rocket ignitor is taped so
that its flammable head is buried in the heads of the matches. The stereo wire is alligator
clipped to the ignitor and your remote ignition system is ready. Our third experiment was
to test the system with a larger balloon outside. We bought the largest balloon that Toys
R Us offered (about 5 times bigger than the standard balloon). Successful again. We were
now ready for the weather balloon. On our chosen day, the weather was poor. We pondered
whether to cancel, but then the rain stopped. Project Weather Balloon was launched. We
began to fill the balloon and then tied it off with kite string. We prepared the MegaMatch and
ignitor and taped them into position. As we prepared to move to the soccer field the rain
began again (and the temperature was in the fortys. Typical June day in North Carolina). I
found it rather ironic that water molecules began to fall from the sky as we prepared to
make our own. Luckily, the matches were on the bottom and the balloon was so BIG that the
rain was dripping off the sides before it got to the matches. We had several aborted
trials which we eventually found out was due to our battery. When we switched to a 12V
videocamera battery, we got quick results.
The flame sprouts and you can see a ring of
gas and the string is still hanging.
The balloon we used was a 4 foot
diameter weather balloon filled only with hydrogen. We decided not to premix because we
had never used a balloon of this size. Many experiments led up to this successful water
synthesis. In the smaller balloons that I explode in the classroom, I use a candle taped
to a meter stick to initiate the reaction. With this balloon, we had to develop a remote
ignition system. The obvious choice was the system we had already been using for other
remote ignitions. This system consisted of a model rocket ignitor, stereo wire, and a 9V
battery. We decided to try it with a standard balloon first. It was a good thing we did
because it didn't work. The ignitor flared long enough to melt the balloon, but was not
able to also initiate the reaction. We pondered other ideas: flaming arrow (Where would it
land? Too risky. Sorry Dan), methanol soaked string attached to balloon (It works, but the
methanol evaporated quickly among other problems), and black powder fuse (Never tried).
However, as I considered the problem (short burn time) more carefully, a simple idea
struck me and the MegaMatch was born. A MegaMatch is 6 or more matches taped together in a
bundle. Our first experiment was to see if a rocket ignitor could ignite a MegaMatch (it
did). Our second experiment was to see if this would work with a small hydrogen balloon
(it did). The MegaMatch bundle is taped to the balloon and a rocket ignitor is taped so
that its flammable head is buried in the heads of the
matches. The stereo wire is alligator
clipped to the ignitor and your remote ignition system is ready. Our third experiment was
to test the system with a larger balloon outside. We bought the largest balloon that Toys
R Us offered (about 5 times bigger than the standard balloon). Successful again. We were
now ready for the weather balloon. On our chosen day, the weather was poor. We pondered
whether to cancel, but then the rain stopped. Project Weather Balloon was launched. We
began to fill the balloon and then tied it off with kite 
string. We prepared the MegaMatch and
ignitor and taped them into position. As we prepared to move to the soccer field the rain
began again (and the temperature was in the fortys. Typical June day in North Carolina). I
found it rather ironic that water molecules began to fall from the sky as we prepared to
make our own. Luckily, the matches were on the bottom and the balloon was so BIG that the
rain was dripping off the sides before it got to the matches. We had several aborted
trials which we eventually found out was due to our battery. When we switched to a 12V
videocamera battery, we got quick results.
