I'm going to use the science of maths to predict that the wrong qotw will win todays vote.
VOTE FOOT IN MOUTH.
( BraynDedd Natasha Kaplinsky's labia majora, Thu 16 Aug 2012, 13:26, 2 replies)

Home made gunpowder
Mid 70’s. There was a camera shop in Accrington from which you could buy any chemical to do anything – seriously - any chemical. We would walk in, in snorkel parkas and platform shoes, and regularly buy over the counter a bag of sulphur, a bag of powdered charcoal and a bag of potassium chlorate, or saltpetre or any oxygenator you care to name (and I fail to remember) all without question. Also magnesium tape, the funny explosive metal kept under oil, any concentrated acids, glycerine for etc etc)

The sulphur, charcoal and pot chlor needed to be mixed as a specific percentage and to do this I was using a large pestle and mortar – in the kitchen. I had decided to ignore/was ignorant of the fact that there may be an element of friction involved in this act.

Soon after the mixing commenced there was a woosh and the bowl ignited in my hand, the flames leaping up my arm. I like to think the mixed stuff went whoosh and fortunately there wasn’t enough mixed for it all to go BOOM. What to do????? Put it in the food cupboard.

The contents continued to burn and acrid white smoke emanated from the cupboard filling the kitchen and most of the downstairs rooms. On opening the cupboard everything was coated in white ash and the bowl had melted it’s way through the shelf. All the foodstuff were tainted with an acrid sulphurus residue and the rest of the kitchen simply stank.

I’m surprised I survived, 1. The explosion and 2, the bollocking for buggering up the kitchen cupboard which had to be ripped out.

Hint: Don’t mix gunpowder with a pestle and mortar.
(HildaOgdensdogsdead DILLIGAF. Well?? Do I??, Thu 16 Aug 2012, 13:10, 4 replies)

I once knew a guy
Who had a home-made tattoo gun powered with the battery pack of a ZX Spectrum. Yes, really. When I say "guy", I mean my friend's older brother, when I was in primary school and he was in third year (grade 10 to our English brethren). The power connection was dodgy, so the gun used to go "DIH-DIH-DIH-DIH-dih-dih-dih-DIH-DIH-DIH-DIH-DIH-DIH-dih-dih...DIH-DIH-DIH-DIH-DIH-DIH" - fast for a moment then wavering drunkenly. What did he get tattooed on his shoulder? Well, it was back in 1991, the time of RAVE, so he got:

THE SHAMAN

I think he meant to get:

THE SHAMEN.
(McChinaman banned, Thu 16 Aug 2012, 13:07, 2 replies)

Petrol - It's good enough as it is.
As a pyromaniac youth in the mid 70’s a friend (RGP) and I decided that the petrol we were using to blow up Dinky toys, drop in petrol bombs off bridges, use as lamps as we toured East Lancs sewer systems (washed clean by the copious rain) wasn’t ‘powerful enough’.

Over a short period of time between us we knicked from school everything required to distil petrol – conical flasks, tripods, bungs, rubber tube even a foot ish long spiral distilling condenser.

We set all this up on the garage floor, added petrol to the flask and placed under it a small meths Bunsen burner. Cooling water was run occasionally through the coil to condense the soon boiling petrol. Excitement was palpable as two 13 year olds chatted about blowing more stuff up. As expected the ‘more powerful’ petrol dripped from the end of the condenser into an open topped flask.

Unknown to us was the fact that the petrol fumes were climbing out of the open topped flask and were slowly spreading across the garage floor. Eventually, after I guess being wafted around the garage by our walking about the fumes reached the small Bunsen burner under a quarter full flask of petrol.

Whooooomph it firkin went!!

The pressure in the garage rose and our ears popped. My trousers were on fire, along with all the hairs around my ankles. The smell was appalling. The flasks remained in tact and the fire was quickly beaten out (thankfully) however in our panic to escape we found that the garage door was now the shape of a large dustbin lid and was off it’s hinges. I’m surprised we survived, 1. The explosion and 2, the bollocking for buggering up the garage door.

Petrol is quite powerful enough as it is. Leave it alone.
(HildaOgdensdogsdead DILLIGAF. Well?? Do I??, Thu 16 Aug 2012, 12:51, 3 replies)

It's a bit like splitting the atom...
When they started putting those widget things in beer I couldn't resist investigating one. Having drunk the beer and split the can I was left with a small plastic cylinder with a simple valve in the top. The cylinder appeared to have been manufactured in two parts as it had a seam running round the side. "That looks like a push-fit," I thought, "should be easy to pry open with a screwdriver." This proved to be the case, but I had neglected to consider that it might contain residual gas - under pressure. This also proved to be the case as the top half of the widget flew across the room with an almighty BANG! and my underwear was no longer pristine.
(minimalist ..., Thu 16 Aug 2012, 11:17, Reply)

2 Cans post reminds me of this
news.bbc.co.uk/1/hi/8257153.stm

Surely this guy wins. Great story.
(Dan dan dan They tik urh jerbs!!!, Thu 16 Aug 2012, 10:47, 3 replies)

When I was 14 I built a 10 foot wind turbine out of a drainpipe and some bits from an old VCR.
In strong winds it generated enough power to dimly light a small green LED
( 2 Can Chunder Word to your mums, I came to prod bums, Thu 16 Aug 2012, 1:00, 4 replies)

Like The AlmightyBeev, I perform 'experiments' as part of my job.
But as I am a classroom science teacher, they are largely all in labs, rather than in my home. Having said that, one of the things I like to do is simulate 'playing with fire' situations in the lab, and demonstrate how not to react to them. It's almost like some of the stuff the kids learn could actually be useful!

For instance, what to NOT do when you have been playing with a candle, and it has started to burn out of control a bit...
www.youtube.com/watch?v=4kemgB_o_j4

I also (as a stupid trick to show off to 11-year-olds) taught myself to eat fire. www.youtube.com/watch?v=es3iw_d39T0 Hint, it's just cotton wool, but make sure you get all cotton and not the stuff with nylon in, or it melts into your face and big tears happen.

Anyway, when kids ask me how to do this, I tell them (very truthfully) that it is not as safe as it looks. For instance, when I was learning how to do it, I burnt off half of my movember moustache. Then when I was teaching a fellow science teacher, he burnt off half of his moustache. Then when I was trying to teach my brother, he burnt his fingers, dropped the burning ball of cotton wool, and burnt a nice hole in my carpet. The bell-end.
(Serotonicity was a naughty boy on..., Thu 16 Aug 2012, 0:31, 2 replies)

Making science - the Beano way
Back when I was about 5 or 6 years old, I had started to read the Beano comics for the first time. One Beano cover had Dennis and Gnasher up to their usual menacing antics, with Dennis probably firing his pea-shooter, but Gnasher was blowing into a pepper pot, to make their victims sneeze.

So, that's where I started my experiment. Could I make people sneeze, just by blowing into a pepper pot? I sneaked into a room, with a pepper pot in my hand, breathed in a gulp of air, and proceeded to blow into the pepper pot.

A cloud of pepper had gone straight into my eyeballs, and I had to be taken to A&E, to make sure my eyes weren't permanently damaged.

Conclusion: Science in comics isn't always accurate, but I managed to discover the effects of pepper spray.
(The Entity Remembered his login details on, Thu 16 Aug 2012, 0:10, 4 replies)