I was at the hospital today, having blood drawn for all kinds of nifty tests (I have to do this every so often. I’m a terrible insomniac, and they keep taking blood to check iron levels at various times during the day, but all of this is immaterial to my question…just giving background), when the gentleman next to me starts engaging his neighbor on the other side in conversation. I’ve spoken with this gentleman before, and, while he’s a nice enough guy, I discovered after about ten seconds that he’s full of crap. Anyway, he was explaining to his neighbor how a projectile bomb could be made using essentially just the sulfer scraped from match heads, and an ordinary ink pen. The skeptic in me disbelieves this, but since ballistics isn’t my field of expertise, I figured I would pose this question to the Teeming Millions™. Can a bomb be made from an ink pen and sulfer?
[sub]Note to moderators: I am not interested in the solution so that I an contruct one. I’m asking because I believe in fighting ignorance, and either he or myself is ignorant in this field.[/sub]
I know you can make rockets from paper matches, and in the days of my misspent youth I made a number of unwise experiments with matches, model rocket engines, and rubber cement. I believe it would be possible to use a great many strike-anywhere matches to make some kind of flashy, poofy, possibly fire-starting thing. I don’t know if you would get much bang for your buck containing it within a pen cartridge, though.
The components of a bomb include: An explosive, an ignition and shrapnel. So any combination of these 3 items would in theory make a bomb. How big the bang would depend on the exact materials. I’m trying to be as vague as possible so nobody gets any ideas.
As Ethilrist said anytime you collect a bunch of flammable stuff you have the potential for a bomb but also as mentioned I doubt it’d be of much practical use. Part of what makes a bomb deadly is the very rapid burning of whatever it is your burning. For example I think DetCord burns at something like a few kilometers a second. Match stuff on the other hand would probably take minutes to burn just one kilometer. Match sulfur just doesn’t quite get you there so your pen ‘bomb’ is likely to fizzle and sputter. Theoretically containing it would make it go bang but the sulfur needs oxygen to burn so more likely it’d ignite at one end and sputter its way to the other.
I just can’t picture that a chemical reaction (burning) could propgate this quickly along a wire (ie kilometers per sec). I am obviously ignorant of the chemical properties that allow it to do this. Is there cite or site that explains how this works?
We used to make stink bombs with Bic click pens and strike anywhere matches. Stick two matches into the spring (head first) and place the match/spring combo where the refill fit. Then you slam the click part down and toss. The smell was quite noticeable, and there was a small woosh, but no bang.
This gets into “stuff the mods don’t like”, but lots of ordinary materials become very explosive when dried completely and ground (or otherwise made) into a powder. Ever head of grain tower explosions? -Some powdered metals are listed as a commercial explosives by many authorities.
Some matches can be made to explode violently, but they have to be ground into a fine powder. To do that, you need to introduce an apropriate liquid solution that will allow you to grind the match heads up without igniting them, but that can be removed afterwards by some means without affecting the chemical composition of the match heads.
Elsewise, it will blow while you’re grinding it.
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I have a survival book somewhere (Ragnar Benson’s Survivalist Encyclopedia) that says that 3 strike-anywhere match heads are an aproximate substitute for a powder charge equivalent to a .38 special. It ain’t good for the gun though; -interestingly enough, most improvised explosives burn too hot and too fast to be used as good firearm propellant.
Also, in that same book, I believe there is an account of an assassination carried out years ago, that involved a thick expensive executive-type pen. The explosion blew the guy’s arm off, and the concussion was fatal. - MC
Astro: “I just can’t picture that a chemical reaction (burning) could propagate this quickly along a wire (ie kilometers per sec). I am obviously ignorant of the chemical properties that allow it to do this. Is there cite or site that explains how this works?”
Your intuition is good. The reaction is a detonation wave, and is a combination of a physical and chemical propagation.
Firstly, you need an explosive which is capable of detonation. Some are very easy to detonate, others will either detonate or burn, depending on the circumstances, and some e.g. gunpowder cannot detonate and need to be confined to cause an explosion. Match heads will not detonate.
The way it works is, you initiate a violent shockwave into the explosive material. The shockwave has to have a speed greater than that of sound in the explosive material. Put a big supersonic shockwave into an inert material and it very rapidly loses energy and attenuates to nothing. Put a big supersonic shockwave into a detonating explosive, and the pressure spike at the wave front triggers the chemical reaction as the wave passes, adding energy to the wave and allowing it to propagate rather than attenuate.
Detonation speeds are normally of the order of kilometres per second, which is why detonating explosives do not need confinement - the whole block of explosive is converted almost instantaneously into a “block” of hot gas with a truly monumental internal pressure. This then expands, rather fast and with little concern with what’s in the way!
back to the OP - match heads contain a lot more than just sulphur. Safety matches contain potassium chlorate and antimony trisulphide which is quite a peppy mixture really. The ignition reaction is between the chlorate and red phosphorus in the striker strip. “strike anywheres” add phosphorus sulphide to the head so they can be ignited by plain friction. Without going into too much detail, the guy in the hospital is right in that you could could probably make a device that makes a loud bang and is capable of injury, but you could probably do more damage with a big store-bought firework.
Wouldn’t oxygen still be a limiting factor in the ‘pen bomb’? I thought that gunpowder and the bomb Timothy McVeigh made include a source of oxygen locked in to the components of the bomb itself (fertilizer in McVeigh’s case…not sure about gun powder).
In our pen bomb it doesn’t seem as if enough oxygen would be present around the burning match stuff to allow it to burn in fairly quickly. As mentioned above my guess is the whole thing would burn fairly slowly and probably not net you a bang worth anything. Certainly, even in the presence of plenty of oxygen, you can watch the business portion of a match burn from the tip to the base of the sulfur (and other stuff). Most matches I’ve lit take a good second or two to finish the initial ignition. The same amount of gunpowder or DetCord would likely flash in an instant if lit.
(I am assuming that the components in a match don’t contain their own source of oxygen which would make this particular post moot.)
Match heads don’t need added oxygen to burn. Like many pyrotechnic mixtures, matches “include a source of oxygen locked into the components”. Potassium chlorate, and potassium dichromate are two of the more commonly used oxidizers.
The rate of the ignition reaction of match material is kept slow in order to give the wood or paper match stick time to ignite. That doesn’t imply that the mixture lacks an internal supply of oxidizer.
Well nuts: in regards to the OP, yes, you can make a pen-sized bomb capable of injury, but no, probably not so easily, and no, not only using sulfur -matches got more than sulfur in them. Powdered sulfur does burn, but rather slow and bubbly like road tar.
The big problem with playing around with powdered match-head explosives is that it is a contact explosive as well as an ignition explosive. You want your mix to go off when you light it, but not ever otherwise. - MC
I could see how you could propel something small like a pen with match-head material, but a bomb? I highly doubt it.
As MC said, sulfur burns slowly, at least slowly on time scales we’d need to talk about to get into generating compression waves from explosions. The sulfur and oxidizing agent in a match serve to keep the match burning, not to ignite it initially. Match heads do contain small amounts of ignition compounds (usually phosphorous compounds) which do burn very quickly and violently to get the match lit, so you could probabably make some kind of bomb out of that. The trouble is, the amount of ignition compound used in matches is so small that you’d be scraping match heads forever before you could amass enough of the compound to create an sizeable explosion. In the end, you’d probably end up with a slow burning firebomb rather than something that explodes.
Caldazar: “As MC said, sulfur burns slowly, at least slowly on time scales we’d need to talk about to get into generating compression waves from explosions”
I could be wrong here, but I’m not sure that match heads contain elemental sulphur at all. Various sulphides, but not the yellow stuff. But then, I’m only familiar with European matches.
Like Squink, I can attest to the bang you can get if you confine a matchhead properly. Try cutting off a single matchhead and wrapping in aluminium foil. You want to wrap it tightly but without any airspaces or holes. Then hold it in a paperclip and heat it in the flame of another match to get a bang. It may take a few attempts to get the confinement right.