Happy new year to everyone,
this is the first year i didn't prepare smth for new year, but i've been sick so didn't have much time ( i follow the rule never store unstable
stuff).
I was wondering if it is possible to prepare a nice and harmless blast with calcium carbide:
I tried to put a stone of calcium carbide with some water inside a plastic garbage bag, put a broken lamp inside connected to some wire, sealed
everything with tape, and tried to blow it up.
Total failure..
I suppose the flammability ratio of CH2CH2 in air is quite narrow..
Any other suggestion for a working simple device? (calcium carbide inside a plastic bottle is a safe classic, but is just a pressure blast, i want it
to burn instead)
H2 and O2 mixture from electrolysis work wonderfully but is rather slow and troublesome to make. Formatik - 31-12-2008 at 20:17
No, the flammability limits of C2H2 in air is extremely wide. In fact, they don't get much wider. Acetylene itself when compressed,
or in the solid state is a shock sensitive powerful explosive about as energetic as TNT. When mixed with air as a gas it is also quite powerful, you
can see this moron (after 3:20) casually throwing a garbage bag full of air and C2H2 and the powerful detonation that results, that looks like it almost
injured him. A shining example of what not to do. Most demonstrations I've seen of H2-air use a stick (or long matches) tied to a long yard or two
stick to ignite it. If you want to make a bang you can fill a small balloon with air (blowing, air pump, etc.) and then a highly flammable gas with
wide explosive limits (H2, C2H2, etc), propane, MAPP, etc. can also be used but are much more narrow in their explosive limits (and then only around
9% of the total volume should be the flammable gas, the rest air), while wearing at least face shield. Besides the obvious like flame or fire, the
main risk here to worry about when filling something up like a balloon is electrostatic shock.
[Edited on 31-12-2008 by Formatik]Nevermore - 1-1-2009 at 00:57
that's why i prefer using calcium carbide!
i loosely filled the plastic bag with air, the put a stone of carbide inside and a plastic glass with water, attached the igniter, sealed the bag with
tape
and shaked it to tilt the water.
then waited approx 20-30 secs till the ballon filled and gave energy to the igniter.
nothing happened.
I pierced the bag from distance using an AC gun and waited till it deflated completely, then examined what happened.
the igniter went nicely but seems that was not enough to set the acetylene.
I will try again in a later time using a spark igniter or a very long rod with a flame.hissingnoise - 1-1-2009 at 07:48
Quote:
Originally posted by Nevermore
I was wondering if it is possible to prepare a nice and harmless blast with calcium carbide:
Way back when I was a kid, carbide was very popular for bangs.
We used tin cans with perforated lids; carbide and spit was dropped in, the lid was closed and a match-flame applied to the fuse-hole.
One guy, I remember got a sooty flame from the hole and decided to blow (I kid you not) into the hole.
The thing went off and he ended up with huge bee-stung lips for week.
It shouldn't have been hilarious, but. . .
Another guy decided he'd rid himself of some rats living in a sewer close to the kitchen-wall of his house.
His pregnant wife was inside preparing lunch.
He dropped a couple of ounces of carbide into the manhole and threw lighted matches at it.
One eventually went in and the sewer exploded like a bomb; pots, pans and crockery crashed to the kitchen-floor.
The floor, itself rose several inches because the sewer, apparently, went under it.
The wife had luckily just left the room, and I heard she was shaken, but unhurt.
So messing with this stuff can have dangers if you're careless!Paddywhacker - 1-3-2009 at 02:21
If you want to do your duty by pruning some of the dross out of the human gene pool then combine your acetylene generator with an oxygen generator
.... hydrogen peroxide plus manganese dioxide ... in the same balloon or bag.hissingnoise - 1-3-2009 at 05:04
Quite! A bit E+W, though! Try to ensure the dross you prune isn't you!
All is dross when "eugenics rears its ugly head".
Much simpler to strike a neutral welding flame on an oxy/acet torch and mark the valves at that point.
When the valves are opened to that point you'll have the correct ratio for complete combustion.
Then fill your bag or whatever.
Something daftly similar was tried on an industrial building site in a large wall-cavity.
The wall looked like it had taken a tank-round.
Windows in the vicinity were shattered. . .Paddywhacker - 1-3-2009 at 12:52
hissingnoise, if the poster is going to kill or injure someone, then the first person killed or injured should be themselves. That is only fair.
Whether or not we would all be better off with the loss is probably, as you hint, o.t.hissingnoise - 1-3-2009 at 13:41
Indeed Paddywhacker, C2H2 in air is practically an HE; admixed with O2 it's nitro in gaseous form with a density almost equal to that of air.
It really is something not to be trifled with. . .Nevermore - 1-3-2009 at 23:32
couldn't agree more.
so far i have not found a reliable way to ignite the plastic bag, but when they do ignite, the blast is very "noticeable"..Mr. Wizard - 2-3-2009 at 09:04
Static electricity from a plastic bag will also set off the mixture. Unless you actually want to be deafened, blinded and eviscerated, shortly before
dying, don't be around plastic bags full of this stuff. If you insist on tempting fate, at least consider using something to remove the static
electricity danger.
Although this isn't exactly on topic, it will be close enough to make you think.
[Edited on by Mr. Wizard]Nevermore - 4-3-2009 at 01:12
Mr Wizard, i never ever work with filled bags, i do put a glass of water inside then drop a piece of carbide and close the bag. I already noticed that
the mixture is extremely flammable and i wouldn't risk that static would set everything off.
I have been looking for aluminum bags that could be grounded but i was unable to find them...densest - 4-3-2009 at 09:04
If you absolutely must do this,
1) put nothing in or near the bag you would not want embedded in your eye, skull, or hands - that means no glass, PVC or other rigid plastic, or
metal
2) use HDPE (high density polyethylene) for any waterproof container, because it is much more likely to stretch and flow rather than shatter
producing sharp objects
3) use cardboard and paper instead of wood or metal because they shred into confetti rather than shatter into pointed shards
4) use small bags.
good luck
you'll need itMr. Wizard - 4-3-2009 at 15:17
When I posted about the bags I wasn't addressing anyone in particular, especially the OP. I realized this stuff may be available to be read by anyone
for centuries. The people who read it may not be as sophisticated about the dangers; and I am trying to save them the pain of a nasty accident.
We post in todays world and we don't realize what we say may be here to be read for ever. A little caution can't hurt anyone.PHILOU Zrealone - 25-3-2009 at 07:46
The use of graphite spray of moisturised air into the bag helps preventing from static electricity.
