Fine Silica powder strikes me as probably one of the least flammable materials there is… It’s just pulverized sand dust isn’t it? As silica means sand.
I’ve actually done that with diesel fuel and a 3 gallon weed sprayer. Metal nozzles make it last much longer. A buddy tried to use ether in a weed sprayer, but it’s so volatile that the flame cloud doesn’t get much further than a foot or two before the fuel-air mixture is too thin to support combustion.
Then there’s plain old ghetto napalm you can make with kerosene and styrofoam. I don’t recommend that. It sticks to everything, and is basically just a destructive mess.
ETA, styrofoam napalm is also really hard to work with, due to the solvent nature of kerosene along with the difficulties posed by the fumes, and the fact that mixing styrofoam with kerosene doesn’t create a fluid and usable gel, but rather something more like a lump of hazardous, insanely sticky phlem. It’s gross, slimy and doesn’t break up into a gel, so much as coagulate into a giant deflated amoeba.
3 Likes
oh, man, we damn near burned down an outbuilding setting huge blocks of styrofoam under an over-hanging roof. same crew of dudes as the supersoakers, too, heh :^)
1 Like
-The cornstarch flamethrower is ready for the video shoot, where should we set up to capture the best light?
-How about over there in that patch of dead, dry thatch?
[scene]
“Just” a destructive mess? Isn’t that the point???
The trick is to not spray it in a dispersed-droplets pattern, but as a long stream.
Diethyl ether will be a poor fuel. Way too easy to ignite, way too volatile so its vapors are an explosion risk (the other kind of “friendly fire”), and evaporates too fast for having a carry-over effect with sanely thin stream. (Brain, stop. No imagining of a firehose stream of burning diethyl ether!) Dibutyl ether, a heavier lazier molecule, may be a better choice, ethers-wise.
If you like living fast and dangerous, a good flamethrower fuel is triethylaluminium. No hassle with ignition as it is pyrophoric, and can be thickened with e.g. polyisobutylene, for a pretty good incendiary gel. Many organometallics can be substituted for TEA with a similar effect.
Also, consider trying a pressure washer, though depending on the fuel you may have to replace the gaskets; Viton is a good fluoropolymer elastomer compatible with most fuels.
Yes. You’d need fluorine, or chlorine trifluoride, to get silica to burn. So one more bottle to carry. But a silica-in-fluorine flamethrowin’ fire could be quite a sight to see!
I know I’d watch.
From distance.
Given that the heat is mostly thermal radiation, could cooking-grade aluminium foil help here? The nozzle would have to be redone in metal, or (better) ceramics, with a heatsink, though. I don’t suppose the exhaust velocity of a Super Soaker class of ejector is high enough to quench burning of the fluid until it decelerates in a suitable distance from the nozzle. (The pressure washers should be able of that trick.)
Beware, that stuff runs HOT! Stay away especially from the righteous kind.
Ever saw the oxygen lance improvised from spaghetti?
I’d say it is more similar to a pulverized coal burner.
What you are talking about instead is a dust explosion. A friend broke his school’s fume hood when igniting a flour dust in a glass flask. These things are powerful. No wonder the same principles are employed in thermobaric weapons.
As LDoBe said, silica won’t burn, at least in oxygen-based atmosphere. But if you’d use something better, e.g. magnesium or aluminium powder, THEN it could be pretty spectacular!
2 Likes
Random thought. What about taking a cue from the homemade soap techniques? Hydrolyze the fats/oils, prepare the sodium stearate solution (by “stearate” we loosely mean the mix of fatty acids from the feedstock), alternatively dissolve conventional washing-grade soap flakes if you don’t want to bother with lye and want to cheat, then precipitate the aluminium stearate with e.g. a solution of alum, filter and dry, then use for thickening of gasoline? It is what true napalm is based on.
…todo…
3 Likes
The last time I made napalm I was a teenager. The supplies were a 5 gallon jerrycan of kerosene we were supposed to use to run the cabin’s furnace and lights, a 5 gallon plastic bucket, and a box full of polystyrene packing peanuts. This was even before I took high school chemistry.
I’m not in the business of messing around with chemistry much anymore. It’s too easy to get your face melted off if you don’t have the right glassware and fumehoods and good textbooks and such.
ETA, that thermic lance made out of spaghetti was hilarious. I suppose anything that can oxidize would work acceptably in a thermic lance anyway, as long as there’s enough oxygen, and good pressure.
That’s where the goggles and the face shield come in. And the back porch or at least a window, because the nature is the best fume hood.
And small amounts of stuff, before you get a good hang of it - and then scale up carefully as many things don’t scale up linearly; the heat production/cooling is the most treacherous - the heat exchange surface grows with square of flask volume, the heat production volume grows with its cube, and thermal runaway is a nasty surprise.
Glassware is not that strictly needed to be “original chemical grade”. As long as material compatibility and heat resistance (and heat transfer rate, etc…) is satisfied, anything goes. That said, lab glassware is more comfortable to handle; but the kitchen section of IKEA provides quite a range of alternatives. (In turn, lab glassware is nice for “normal” cooking, too.)
1 Like
The moment you said “Ikea” I had to share this: http://youtu.be/ewUVsYVOqtA?t=42s
2 Likes
Custard powder works like a charm too, with the added bonus that you can use the left over to brew up some non newtonian fluid.
Nothing more pointless than an ineffectual mess. Nobody likes cleaning that up.
I’ve cleaned up, though, with some satisfaction, a few pointed messes.
I used to make styrofoam-in-toluene varnish/glue when I was a kid. Of course I tried to burn some. Made some quite nice black-brown bubbly residuum.
1 Like
Yeah, residuum. Let us never admit that the whole point was just residuum. The aftermath. The pulsating, sputtering, physical testament to “what the fuck just happened there”?
4 Likes
I’m not sure if the number is in the plural billions for ‘starve’(possibly for ‘are malnourished to some degree’).
That aside, though, it’s worth remembering that while this project is a highly visible (and, thus, apparently emotionally salient) arguable waste of a pound or two of corn starch, it is absurdly insignificant compared to somewhat more subtle; but vastly larger, inefficiencies in the food supply chain. (And don’t even start on the human costs of various non-food luxury and entertainment items…)
I’d bet nontrivial money that eating a hamburger wastes more plant-based food calories in the quest for improved deliciousness than this project did in the quest for flammable fun. I probably don’t even want to think about what MSF could have fixed for the price of the last gadget I impulse bought.
Obviously ‘but look at the other guy!’ is not, in itself, a particularly distinguished argument. However, in a world with more battles than you possibly have time to pick, looking at the other guy is a valuable heuristic for finding battles that are actually worth winning. In this case, I’d argue that burning a modest amount of corn starch is definitely not “What Would Jeremy Bentham Do?” approved; but it’s so low on the list of actual problems that wallowing in its obscenity is vering on moral onanism.
4 Likes
I agree with you that in practical terms a pound of starch is not worth getting upset about, however some things matter on a symbolic level. While there are starving and malnourished people on the planet I will not wilfully destroy food for trivial and childish entertainment. That is disrespectful to those in need but also to ourselves, and demeans the relationship we have to the environment that nourishes us. We should acknowledge that we are enormously privileged and hope that starving people never get to see what we do with food.
If a material is easy to obtain and suitable for an application, the symbolic issues are so low on the decisionmaking tree that they don’t even register at the noise level. Powdered sugar is suitable for testing of laser-sintering 3d printing, and its cost compared to other sinterable fine powders is hard to beat. How does it relate to hunger in Africa? Should I go for something more expensive, where, to add insult to injury, I cannot even eat the printout when it is not useful anymore?
Some nice outrage-baiting example here:
http://www.evilmadscientist.com/2007/solid-freeform-fabrication-diy-on-the-cheap-and-made-of-pure-sugar/
And, back to the starch itself, consider the use of starches in bioplastics, and the polylactic acid (PLA) as plastic material on its own. Also plant-based. So many things are hidden from the watchful eyes of various do-gooders under the veil of technological obscurity, and maybe that’s good.
This approach is why we can’t have nice things, at least without angry shouts from the peanut gallery.
Face it. Any material is either mined (or drilled) at human cost, or grown and processed at human cost. So we get some fun from whimsical use of some starch, gasoline, steel, electricity… So what?
You sound more outraged than me, except that you’re outraged in defence of a child’s amusement. Ultimately this attitude that everything in the world is there for our convenience and amusement is what will destroy us.
It’s actually annoyed and grumbly, not outraged. Difficult to recognize in text, though.
Not a child’s amusement, too. The device’s author looks rather adult. Childish, maybe, but childish amusements are a significant part of what makes the life worth living.
Does that mean we shouldn’t have fun because it’s wrong?
2 Likes
Anyone else notice that he’s standing in a tinderbox of dead weeds? They are probably damp or wet; however, if they were dry, this guy would be bucking for a Darwin award.
1 Like
I think that this is backwards. Start with the large-scale issues. Otherwise, people, being what they are, will mistake having done the symbolic things, will think that they have done their part and cease to look at the larger issues.
Mental accounting is strange. It’s all to easy to think that not wasting food is the same as, for instance donating a few hundred to MSF.
Have fun. Do good too.
4 Likes
