Introduction: 10 Minute Trash/garbage/bin Bag Hot Air Balloons

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About: Hi, I'm Tim. I work on the railways during the day, run a scout troop and have a blog (see above website link) where I discuss my allotment and projects!

Rain fire from the sky with this mockery of a Chinese balloon!

This instructable requires:

- A couple of meters of incredibly thin wire.
- Cheapest trash bag/bin bag liner you can find (these are the sort of bags bin men hate as they split if you look at them funny)
- A couple of balls of cotton wool
- Sellotape
- Methylated Spirits (Denatured alcohol)
- A match
- Cotton for a tether/anchor

"The story goes that in the 2nd century BC someone made an experimental hot-air balloon out of an empty eggshell.  He emptied the egg white and yolk from a hole in the shell, and put a piece of burning wormwood inside the shell.  As the air inside the shell was warmed, the eggshell was lifted by the wind and rose in the air."

"According to historical records the inventor of the hot-air balloon was Zhuge Liang (181-234) a noted politician and strategist of the Three Kingdoms Period"

Quote source: http://tinyurl.com/ykezu7n

I'm not a man who likes fussing around with tissue paper making beautiful flying masterpieces perhaps adorned with calligraphy.  I'm a man who looks under the kitchen sink to find something to set fire to.  Most of this stuff you'll find either under your sink or in your tool box.

WARNING

The balloons will rise gently in the air and if you don't hold on, they'll go a long, long way.  We do these at our local scout troop grounds which is incidentally next to an airport and I suspect they could probably do a fair bit of damage if they come into contact with planes.  The last set we did were visible for about three miles away before they plunged into the sea.  A friend of mine whom happened to be on the beach at the time put two and two together and rang me shortly after saying "Have you been setting fire to bin bags and releasing them into the skies?"

Similarly if you're in a rural location apparently if these land in a field they can be ingested by livestock and the copper wire can damage their stomachs and throats - so be responsible and keep hold of them if you can.

Some people have said that they might even catch on buildings/trees/dried grass etc if released.  Use your common sense, if you're in a very built up area don't release them.

Keep a bucket of water handy to put out the burner if you're not releasing them or it accidentally catches fire (always a risk)

Step 1: Getting the Wire.

You need thin wire for this instructable because it's all about weight!  For this instructable I used a galvanised steel wire about 1mm thick - but thinner is better.  But you can also find thin wire in a multitude of places - speakers, transformers, eBay etc.  You may need to experiment but you're looking for .3mm or less thick.  You can use wire strippers for this, but I'd steer clear of anything other than plastic coated wire because it's a real pain to remove the coatings.

Step 2: Taping It to the Bag

You'll only need four bits of tape - as little as possible.  Two sets of hands (or three if you can get 'em) are an advantage!

First of all you need to make a loop the same size as the opening of the bag.  Cut to length leaving enough to twist the ends together - be careful you don't stab yourself with the wire - but it should be so thin it shouldn't actually cut you.

The next thing you'll need to do is start taping it to the rim of the bag.  ignore any handles (preferably don't use bags with handles) and use just the rim.  The first bit you want to tape is the bit you've twisted to give it a bit more rigidity.  Tape four times equally distance (so divide it into quarters as it were)

Step 3: Putting the Fuel Wire On

The 2nd bit of wire is our fuel wire.  It needs to go from one side of the bag across the diameter.  It loops/hangs down a bit as well.  Because you've taped in quarters you'll need to pierce the bag through the sellotape and secure it (twist it on) to the wire going round the rim. 

Once measured, thread on the cotton wool balls, and fix it onto the bag.  Pierce through the bag through the tape and twist it.

Step 4: Holing the Bag - Optional

Optionally you can make a small hole at the top of the bag - this helps the stability, but I've done it both with and without and I've not noticed a lot of difference.  Too big and it'll never inflate.

Step 5: Fueling

When you're ready, take the balloon outside.  Lay it on its side and pour a very small amount onto the cotton ball without getting any on the bag - if you do, you'll have a floating incendiary device which will coat everything in molten plastic as it flies away.  I know because I've done this by accident.

We're tethering the balloon with cotton.  This is because I didn't want it flying away. 

Kiteman has made a very sensible suggestion about putting the anchor on the top of the bag - that means when it reaches the length of the tether it flips over and the hot air is released.  A very valid point and I'll try it this Friday when I make the next batch with the scouts!

Step 6: Lighting & Inflate

Our next job is to light the balloon and inflate it.  Again, using more than one set of hands one person needs to hold the balloon (preferably at the top).  If you've got two people to hold whilst you light, one can open the bottom of the balloon as the other is holding the top.

Using the matches (or a lighter) light the cotton wool ball.  This'll quickly inflate the balloon and the person holding it will notice it getting lighter and lighter until it'll start hovering.  At this point it'll just float, then gently get momentum and speed up.

If fully released it'll generally make the lower of the jet streams and really will hurtle away.  If released at night you'll see the usually clear flames of the meths as a bright blue/yellow floating away.

The cotton ball works as a wick, slowly releasing the gas from the boiling meths stored inside.  A single cotton ball will keep the balloon afloat for about 25 minutes and strong 'jet streams' will carry it miles.  Very pretty.

Unfortunately on this particular event the bin bag got away.  This was not on purpose and it was because the tether got snagged.  :-(  The resulting video was particularly chaotic and I had to do a fair bit of splicing to remove my quite considerable swearing.

The resulting video show the lighting, the inflating but not the release because I asked my wife to let go.  It dropped rather gracefully to the ground, so I swore (again) and turned off the camera to put it out and start again.  Unfortunately it bounced and took off.  I wasn't quick enough to get the camera back on and so we only have a 'look it's inflating' to "omg it's in the sky!"

Enjoy the below short video.