The most Dangerous Project for a 12 year old...
Ok, 8th grade (yep, American with chagrin) Physical Science II class.

"Build a project related to class". Went to in school library and found book on "Fun Science Projects for Teens". Hmmm this looks interesting, "Carbon Arc Furnace".

What this was, was a home-built way to "melt soft metal using electricity".

You see all you have to do it take two batteries apart for the carbon rod inside, mount them to two wooden posts, run lamp wire from a home power outlet, through a OPEN GLASS CONTAINER OF WATER and salt, then to the two carbon rods, when the rods are brought in proximity the electricity jumps across and heats a flat ceramic tile held above it.

The teacher looked at my finished device, dubiously, and asked if it was "safe", of course I said yes. Do I want the lights turned off for effect? "Ok".

Cue me bringing the two rods together holding TWO THOUSAND WATTS of electricity about 12 inches, apparently a death-proof distance, in front of my face (in the dark).

This thing makes the Van de Graf Generator demonstration done in most science class’s cry in shame at their impotence. It made a lighting bolt sound and a 1/4" diameter arc 1 1/2" wide. No one in his or her right mind would let an ADULT build or operate this thing.

Suffice to say I blew the lights in SIX classrooms and permanently was called "Einstein" for the remaining five years of public school.

ADDENDUM: As an after thought I thought I would add that the lampcord was connected to the carbon rods by rapping them around and twisting the wire, the lam cord in the beaker of solution was two bare wires hanging and unsecured the in beaker. The two rods were moved together with my hands less than 1 inch from the rods, bare wires, and beaker leads.

So:

Touch a carbon rod: Die (teacher goes to jail)
Touch a wire: Die (teacher goes to jail)
Knock over the beaker whilst wiggling the contraption and spilling electrified liquid: Die (teacher goes to jail)
Unsecured beaker wires falls out of beaker and touch it:Die (teacher goes to jail)
Looking Directly into High Intensity Ultra-Violet (X-ray) radiation for too long: Blindness (teacher goes to jail)


Footnote: I just decided to build another one THAT"S how cool it was.
(OMG-Hilarious, Sat 15 Aug 2009, 11:45, 7 replies)

Nice one!
Clicked.

But out of curiosity: What was the salt water for - an isolation transformer substitute, some sort of (clearly ineffective) current limiting device?

Also, did you have any after-effects (eye problems from UV exposure)?
( The Incredible Sulk Finally remembered his password on, Sat 15 Aug 2009, 16:15, closed)

I simplified...
... for the story, the salt was actually Potassium Chloride, though table salt worked but not as well, and 500ml of water and 2 tablespoons of this was actually (LOL) the current "limiter". It did actually limit current and would last for about 3 or 4 minutes before you had to replace it as it broke down chemically.

As for eye problems, I never had anything obvious, though who can say 20 years from now, I probally looked directly at the arc for 10-15 minutes all told, and wore absolutely no eye protection, hehe. Thanks for the reminder, I will have to use welder goggles for the next one...
(OMG-Hilarious, Sun 16 Aug 2009, 2:14, closed)

I see; thanks for the clarification.

I was thinking along the lines of short term vision problems, "Arc eye" and suchlike - I think you'd have known at the time if there were any ill-effects. Still, it's always a good idea to protect your eyes.
( The Incredible Sulk Finally remembered his password on, Sun 16 Aug 2009, 2:35, closed)

Sounds great.
I'm Googling that fucker and then making one.... What could possibly go wrong!?
(Oil Slick, Sat 15 Aug 2009, 17:35, closed)

Just as a footnote...
This was in the USofA so 120 volts, 20 amps. 240v British-style would increase the danger 500x.
(OMG-Hilarious, Sun 16 Aug 2009, 2:17, closed)

haha
a friend and i had a penchant for making arc lamps out of power supplies and pencil leads. The teachers didn't mind, most of them were impressed :D
( weaver., Sat 15 Aug 2009, 18:07, closed)

Hehe Cool...
Then your 100% ready for Line Voltage...
(OMG-Hilarious, Sun 16 Aug 2009, 2:18, closed)