This post details instructions for making and launching a fire balloon successfully. Mostly for my own memory.
Acquire these supplies (makes one balloon):
- 1 yard balsa wood strip (just wide and thick enough to hold 8 birthday candles relatively rigid)
- 12 thin birthday candles
- 1 kitchen trash bag (opaque white, the thin, cheap kind)
- super glue
- OPTIONAL: colored nail polish for decorating
NOTES: white trash bags glow beautifully. Nail polish is about the only thing I could find that would stick well, but don’t let the painted parts touch each other; the polish likes to stick to itself more than the bag. you can sometimes find balsa wood at art stores, and always at craft stores.
Make your balloon
cut the balsa-wood strip into two 18-inch lengths (use scissors), glue them into a cross
adhere 3 candles to each of the 4 arms of the cross, keeping them close to the center: put the bottoms of the candles in a flame until they light, drip two drops of wax where you want to place the candle, then quench the flame onto the wood, pressing in firmly for a few seconds
place four tape patches around the lip of the trash bag, an inch or so down from the lip (this will help the bag not to tear)
make four cuts into the taped patches, just wide enough to fit the wood slat through
OPTIONAL: paint on the bag with your nail polish. It should dry quickly even when laid on thick.
NOTES: You should test the balloon at this point in your house, to test the seal and weight. Don’t let it fly into the ceiling obviously. We found ~8 candles was enough when indoors, but when outdoors and in the cold and wind, 12 candles was the minimum.
Launching the balloon
You will need two people at minimum. Pick a spot to launch that is sheltered from the wind for the assembly and launch. Once it is airborne the windiness doesn’t matter unless there are extreme gusts.
Obviously don’t launch under a tree, on a dry day, or any place where things will probably catch on fire when hot birthday candle bits come falling down.
Have a friend hold the bag from the top while you light the candles from the bottom with an extra birthday candle, being sure to protect the loose bag from the flames. Hold the balloon from the bottom when it begins to inflate.
When you can feel it is very buoyant, release it into the night.