Tom,
I noticed that you used "Canada Dry" tins. Remember their old slogan "Drink Canada Dry".
Well at one time I tried but Seagram's and Molson's put on a second shift and they got ahead of me.
Steve.
Hahahah!
That is the funniest thing I have seen all month, thanks Steve, I needed it today ;-}
I did my share of tennis ball cannons but my my uncle Lee back in the mid 60's to an art form with his cannon but I can't remember the details as I was just a pup but it sure was cool launching stuff.
How about dry cleaning bag hot air balloons?
Dangerous as **** most of the time but still fun to see and do.
Just close up the top of dry cleaning bag where the hanger went through with a lighter so it will hold air.
Get two plastic straws or similar light rods and tape them in an X.
Get some tin foil and form a little cup about 1" wide by 1/2" deep, just enough to hold a couple of cotton balls.
Tape the X with the cup to the opening of the bag and 90's so you have a hot air balloon looking thing.
Saturate a couple of cotton balls with rubbing alcohol and light them in the foil tray, hold the top of the bag until it fills with hot air and let it go.
Do this at night for best affect as you your glowing bag of light floats up and off with the breeze and stay aloft depending on temps and winds for 20 minutes easy, usually long enough to loose sight of it and generate calls to 911 or TV news or the like with a UFO sighting HAHAHAAH!
If you really want to be devious launch 5 at a time, that really freaks people out and leads to wild multiple ship UFO sightings that seem to fly in an odd formation no real aircraft could do.
Wind, temp and how big your bag is decides what it will do and how cool it looks.