Kevin, Paula, Zoë and I went out to do the data collection phase of Kevin’s science project–firing the potato gun and measuring the range and flight time of its spud projectiles. And everything went fine … almost. At least, it went fine while the video camera was on.
http://chaos.dendro.com/wp-content/potato-gun-1.mov
e got all our data, we fired off a few more; I shot a golf ball/spud load, and then Paula stepped up to fire (after we coaxed her back down from the van). We switched from propane to the Suave deodorant for the “fun shots”, and naturally, Paula’s load misfired.
A note on misfires. The Spudtech site states:
There are a lot of reasons why your launcher may not be working. First and foremost NEVER take off the cap and start clicking away at the igniter. This again has led to human fires and that chemical thermal hair removal thing again…Hairspray in cold weather just does not go well. Too much of the burnable stuff in the spray condenses on the chamber walls, making it very difficult to burn. You might try warming the chamber by the fire if you are camping or graduate to a lighter, hotter fuel (propane). To ‘defuse’ a misfire you need to take off the cap, while pointing it in a safe direction. Allow the chamber to air out for several minutes, perhaps longer, to get the fuel load out. After you are certain the fuel has been vented, again verify the spark, just by turning the chamber enough so you can see where the spark should be. Never point the chamber bore directly at your face, or body, or anybody else. If it sparks then it is a fuel mixture problem.
So I did a combustion chamber check, removing the end cap and venting the chamber. I waited a minute. I told Paula to click. Nothing.
I looked into the chamber at an angle from a few feet away. “Let’s see if we have a spark,” I said.
She clicked again . FLOOF. A small fireball rolled out of the combustion chamber, past my face.
Kevin fell to the ground laughing.
We reset and Paula got her potato round off. Meanwhile, there was this smell…
Zoë said, “Something smells like popcorn.”
Paula said, “It’s Daddy’s hair.”
Sean M. Gallagher 
Hehe, nice. Next time you all should try to shoot baseballs.
I’m reminded of when I was a kid and I fried myself with an electrical current in mercury switch.
nice job to kevin!!!
congrats to the lab rat ( my older brother)
compressed air would work too and be much safer
Couple of comments on the spud gun & misfires. Not sure where your igniter is located, but we’ve found over the years that having the igniter on the cap is the best way to keep it “dry” from the hairspray and fuel. What happens is the hairspray or fuel “wets” the ignitor and won’t fire. In regards to the brand of hairspray, we find that Aqua Net SuperHold is the best fuel. In terms of ammunition, we only use vegetables and it depends on the size of the pipe, but bakers and yams tend to be the best fuel.