A little light light....

[Divided he ad]

Think we're a little too far  now John !!?     


IIRC it was potassium that blew up the big cylindrical glass bowl that held the water....

Science teachers in my school tended to ignore the instructions  (make themselves cool? )  "size of a grain of rice"  chemistry teacher chopped off a corner ~10mm pyramid kind of shape. Dropped it in and there was a bit of a whizz and a boom.   
Quite exhilarating! 



Just what I recall.... think it was potassium. Could have been sodium... Was a while ago!






Ralph.

[AdeV]

Just what I recall.... think it was potassium. Could have been sodium... Was a while ago!

I find it hard to believe that you can't remember the name of the metal - I mean, come on, it exploded! Surely that should have seared it into your memory forever? Or weren't you into big bangs then? 

[bhowden]

As a teenager I spent far too much time studying chemistry with special emphais on very exothermic reactions.  Early VW transaxle cases were pretty close to straight magnesium.  We would use a wood rasp to grind up a tobacco tin worth at a time.  You used to be able to buy Sodium Chlorate as a weedkiller for about $15 for 75 pounds.  Mix it with the shaved magnesium and you got a very saleable product.  Even mixing NaClO3 with sugar and I could sell it for a dollar for a 4oz bottle.  I always wondered why kids would sell drugs when the markup was so low.  We once tried to light a big chunk of magnesium.  It would sort of burn but not very spectacularly.  Mostly looked like a glowing puddle of liquid metal with little hot spots breaking out every now and then.  It got much more spectacular when we turned the hose on it to end the fun.  Needless to say the fun just started at that point.  Finally ended up burying it in sand to get it out.  I mixed up some thermite in a crucible in the fume hood of the grade nine science lab.  The crucible shattered and sprayed the mixture all over.  Fortunately it went out leaving us dissapointed.   One of my favorite tricks in science class was to fill the sinks with propane.  As long as it was fairly still it would stay there for quite a while until somebody would accidently light it.

Brian

[andyf]

Our school chemistry benches had gas taps, for Bunsens.  If the class all (except the goody-goodies) blew air back down the taps, an gratifying whump! would emanate from the pipework when a Bunsen was finally persuaded to ignite (sometimes by an unwitting teacher), and the flame flashed back and set off the gas/air mix below.

Chris, you're safe from this trick. It was back in the days of low pressure town gas. I think natural gas is at too high a pressure and would tend to inflate your pupils (or students, if that's what they are called nowadays).

Andy

[Divided he ad]

 

This thread has become quite good fun!

Ade, as said... Sure it was potassium but we were "playing" with various metals in the same day. And the old grey matter ain't what it used to be! 


Brian, Very ingenious and entrepreneurial    Stunning what some of us have gotten away with.... Various explosions and the likes over the years!  Propane sink!!! 


Andy, Blowing down gas taps!!!   Not something most of us would have thought of I'm sure!





Ralph.
   

[bhowden]

This thread, now thoroughly off topic, has given me an interesting idea.  I wonder if the home foundry type could use thermite to cast iron.  Make up the normal green sand flask but instead of a furnace and crucible, scoop out a funnel in the sand and fill it with a mixture of thermite and cast iron bits.  In theory you could work out how much extra cast iron it would take to absorb the surplus heat released by the thermite and make the process much more efficient and regulate the temperature of the pour.  Not sure how well it would mix but, in theory you could add other elements to make all sorts of alloys.  Add high carbon steel and get a low carbon steel mix.  The major snag I can see is what happens to the aluminum oxide released by the thermite.  Anybody know if it stays in the melted iron released or if it boils or floats off?  There must be something in all the smoke!

Brian

[raynerd]

Andy, I expect I am safe from that trick. It comes out with such a force that there is a good 2" gap if you ""accidentally"" light the tap directly. Still clever little trick!

[krv3000]

well dun

[Divided he ad]

well dun

    Are we finally back on topic? 


Thanks  Bob 




Here we go  again....       Thermite casting!!!   This I've got to see!!   

 (brave man who tries this one.... Possibly a little nuts too   )





Ralph.

[bhowden]

>>>a brave man that tries this

In the interest of staying on topic and broadening the audience I will repost my original off topic reply as a new posting over in a more appropriate topic.

Brian

[Divided he ad]

Brian,

I'm going in search of that thread now 




Ralph.