Exotic Thermites?

[Boris]

I was looking through the web and came upon this...I looked around and couldn't find anything else about it...I am guessing that it either dosnt work or dosn't work that well.How does this look to you?

EXOTIC THERMITES: Thermites can also be made from teflon-magnesium or metal flourides-magnesium or aluminum. If there is an excess of flouride compound in the mixture, flourine gas can be released. Flourine is extremely corrosive and reactive. The gas can cause organic material to burst into flames by mere contact. For teflon-magnesium use 67% teflon and 33% magnesium A strong first fire igniter should be used to ignite this mixture. Both the teflon and the magnesium should be in powdered form. Do not inhale any smoke from the burning mixture.
If you use metal-florides instead of teflon, use flourides of low energy metals. Lead flouride is a good example. Try using 90% lead flouride and 10% aluminum.
Warning: Flouride compounds can be very poisonous. They are approximately equal to cyanide compounds.
Another exotic mix is tricalcium orthophosphate and aluminum. When this burns,it forms calcium phosphide which when contacts water releases hydrogen phosphide which can ignite spontaneously in air. Tricalcium orthophosphate has the formula Ca3(PO4)2 and is known as white-lockite. Use about 75% orthophosphate and 25% aluminum. This ratio may have to be altered for better burning as I have not experimented with it much and
don't know if more aluminum may reduce the calcium better. It does work but it is a hard to ignite mixture. A first fire mix containing a few percent of magnesium works well.

[Flake2m]

Can you post a link to site where you found this info I would like to some more reading on these mixtures.

The only exotic thermite that I had known about was Magnesium powder and copper oxide. this mixture would burn hotter and be more easier to ignite because it is a very reactive metal vs much less reactive metal.

[kingspaz]

compared to Al carbon is quite unreactive therefore would give up its fluorines (in teflon) relatively easily. then the F would simply oxidise the Al to hell releasing alot of energy and also, quite likely, AlF3 vapour/smoke. this, if in common with other fluorides, would be very toxic and the perfect weapon for taking out vehicles such as buses or other soft skin targets packed with people.

[vir sapit qui pauca loquitur]

how fine should the aluminium be? a few hundred mesh or would course granules do ?

this is VERY interesting....

(sorry a stupid question i know, but i have both ingredients sitting next to my computer)

<small>[ October 02, 2002, 06:42 PM: Message edited by: vir sapit qui pauca loquitur ]</small>

[Sparky]

I believe there is a word on exotic thermites in the rec.pyrotechnics FAQ (search google for it).
A thermite reaction is any metal oxide (or other oxidizer such as flourine) and a more reactive metal. This could be lead tetraoxide/magnesium or bismuth trioxide/magnesium (dragons eggs), copper oxide and aluminum, red iron oxide/black iron oxide/aluminum, zinc oxide/cesium or whatever.
I think teflon based thermite is used as an infared distraction in some military applications (distracting heat seeking missiles).

Flake2m: I haven't tried copper oxide/magnesium but I know copper oxide/aluminum burns quickly (it's no good in salutes though) and is ignitable by normal blackmatch fuse. It vaporizes the copper if you use fine mesh ingredients (not sure about coarse mesh ingredients), so it's no good for melting stuff or starting fires.

vir: From my experience with other thermites, if your aluminum is about 60 mesh or coarser you might need to use a bit more than stoichiometric but it should work. Coarse aluminum is a good thing in some cases because it slows down the thermite (I'm not sure why this is good exactly - so says rec.pyrotechnics FAQ). The finer it is, of course the faster it will burn. If it doesn't light at first, make a hotter burning first fire! Where did you get powdered teflon from, is it a lubricant?

One thing I find interesting about thermite (unconfirmed by me) is that it will burn faster if packed down since it is a surface reaction instead of a gas phase reaction like most pyrotechnic mixes.

EDIT: Flourine is an oxdizer not reducer :rolleyes:

<small>[ October 20, 2002, 12:52 PM: Message edited by: Sparky ]</small>

[Aaron-V2.0]

There is a fairly extensive thread on exotic thermite mixtures over on <a href="http://www.sciencemadness.org/talk/viewthread.php?tid=127" target="_blank">ScienceMadness.org's</a> forum. I've yet to attempt even the normal Iron Oxide/Al thermite though once my father understands that KNO3/Sucrose in a tin can isnt a pipe bomb :rolleyes: I'll try it... Or I'll do it at a friends house.

EDIT: Fixed link.

<small>[ October 02, 2002, 11:16 PM: Message edited by: Aaron-V2.0 ]</small>

[vir sapit qui pauca loquitur]

the powdered teflon is an additive to pump-grease, its quite fine and its sold under the name of driLUBE (actual name) and it comes in 1 kg blocks to add to gallon/5gallon drums of grease into something suitable for high-speed applications (dispite something called bearing lube :rolleyes: ) i used the stuff in my lathe, it does help to soften out any knocking sounds from the bearings (it's an old lathe, second or third hand <img border="0" title="" alt="[Wink]" src="wink.gif" /> )

I have seen spray-on ptfe, and this produces an ultra fine power (probably hazardous to breath in due to size) this could be used.

Dont expect me to try this out at home folks, as the thought of this gas hanging around near me is just scary !

[metafractal]

I think I can end this once and for all...
While it is completeley true that a thermite is just any metallic reaction between a reactive metal and a metal oxide, and there are many alternative methods of making thermite, the term "Exotic Thermites" is right out of the good 'ol Anarchist's Cookbook, and I suspect that it was just a term that the Jolly Rodger came up with while he was pretending to be high from smoking pocket lint and glad wrap. There is no such unique thing as an 'Exotic Thermite', but there are alternative ways of manafacturing thermite which may result in somewhat different properties.
So unless I am mistaken, I would appreciate it (dont want to demand anything, I am far from a mod) if people would stop using this term "Exotic Thermite" along with quite a few other terms that just originated from the cookbook's even if they do have some truth behind them, as it just confuses things and gives them an unprofessional overtone. Otherwise, please correct me if I am wrong.
Hope this was vagueley constructive,
&gt;Metafractal

[vulture]

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica"> A thermite reaction is any metal oxide (or other reducer such as flourine) </font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">AArgh! How can you call fluorine, the most powerful oxidizing element a reducer? (The strongest oxidizer known is not fluorine, but the [KrF]⁺ complex)

Mg + CuCl₂
or Mg + CuF₂
can also be considered as thermite, as well as lots of similar mixtures. One can say thermite is a mixture of a strongly reducing metal with a noblemetal oxide or halogenide.

<small>[ October 17, 2002, 12:39 PM: Message edited by: vulture ]</small>

[Polverone]

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">the term "Exotic Thermites" is right out of the good 'ol Anarchist's Cookbook, and I suspect that it was just a term that the Jolly Rodger came up with while he was pretending to be high from smoking pocket lint and glad wrap. There is no such unique thing as an 'Exotic Thermite', but there are alternative ways of manafacturing thermite which may result in somewhat different properties.
So unless I am mistaken, I would appreciate it (dont want to demand anything, I am far from a mod) if people would stop using this term "Exotic Thermite" along with quite a few other terms that just originated from the cookbook's even if they do have some truth behind them, as it just confuses things and gives them an unprofessional overtone.</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">I wasn't even aware that the "Jolly Rodger" had used the term "exotic thermites." What would your short, descriptive name be for "thermite-type mixtures that do not necessarily use aluminum as the reducing agent or oxides of iron as the oxidizing agent?" And if you'd tried some of these exotic thermites, you'd be saying stronger things than "there are alternative ways of manafacturing thermite which may result in somewhat different properties." The difference between coarse Al granules with ferric oxide (a traditional thermite) and aluminum dust with cupric oxide (an exotic thermite) is night and day, and these teflon-based mixtures are very different from traditional thermites as well. Though I don't know that I'd even call them thermites, as they aren't producing any free metals on ignition. Nonetheless, they're very interesting.

<small>[ October 17, 2002, 01:46 PM: Message edited by: Polverone ]</small>

[Anthony]

I'm sure the term "exotic thermites" was in use before the Anarchist CrapBook. I know the term is used in the PFP database.

[metafractal]

Anthony, are you sure about that? Remember that some of the cookbooks are from as early as the early 60s.
Polverone: I have no primary sources to suggest that the term Exotic Thermites was coined in an unreliable source like such. But I have been lead to believe this by a secondary sources. Also, according to dictionary.com:
ex·ot·ic Pronunciation Key (g-ztk)
adj.
1. From another part of the world; foreign: exotic tropical plants in a greenhouse. See Synonyms at foreign.
2. Intriguingly unusual or different; excitingly strange: “If something can be explained simply, in a familiar way, then it is best to avoid more exotic explanations” (Chet Raymo). See Synonyms at fantastic.

This dictionary definition of exotic does not quite fit, but this is debateable. As you point out, they are hardly thermites. It really comes down to the definition of thermite, and how different it would be to someone unfarmiliar with the chemistry of thermite.
Nonetheless, when I really come to think of it, no matter where it was coined, It has come into reasonably mainstreamly use with the broader, more professional/responsible pyrotechnic/explosive community. Or has it? If so, I suppose revise my stance to lassiez-faire, as this is simply the way linguistics evolve, and to begin a debait about this would somewhat pointless and pretentious. It is still interesting, though, to trace back the origin of someone calling this type of reaction an "Exotic" Thermite... Do you really see a chemist naming a reaction that bares close resemblence to another just an "Exotic" reaction? (No retoracy intended) Do you hear about more obscure crude-oil derivitive mixtures being called "Exotic Kerosenes"?
Just my two cents...
&gt;Metafractal

[Anthony]

My point wasn't that the PFP database is older than the ACB, but that the term is widely accepted in responsible literature.

[MacCleod]

Sparky,I think the reference to 'slowing down' the burn rate has to do with thermite's commercial use of welding/cutting metals.If the thermite burns too rapidly,the molten metal slag would be thrown rapidly outward ,rather than pouring onto the target surface.
Oh,you can buy PTFE powder from Skylighter and Pyrotek.

[Phoenix]

some time ago i found a mixture of Al/CuO in the lab
i poured some of it in a teaspoone like metaltool ( i dont know the english term for that it is often used to burn sulfur)
and heated it over a bunsenburner
nothing happend, the stuff started glowing but did not reakt
suddenly it went off with a loud bang
i really wonder how this can happen because Al melts before it starts glowing and liquid Al should normaly reakt with the CuO

[Polverone]

If you have fine Al powder, each particle is probably coated with a thin layer of Al2O3, which has a very high melting point. If you heated a CuO/Al mixture in a deflagration spoon (I think that's the term you want), it's conceivable that the aluminum had melted, but not reacted with the CuO (because of insufficient temperature at any one point) and not flowed together to make a visible liquid because of the fine particle size and mixing. But once there's enough energy at any point to start this self-sustaining reaction... BANG! The whole heated mass reacts nearly instantaneously. That'd be my take on it, anyhow.

[simply RED]

I have many problems with thermite.
First i found such Al powder that it burns when its ignited in air (ignited with a match)! Then i found the rust and heat it until it gets darker. Mix extremly well the rust and the Al and...
something does not work... it burns too fast, or it does not get ignited or it burns to its half and stops. It can't melt anything.
I use the proportion 2Al + Fe2O3 = Al2O3 + 2 Fe
calculated in mass.
Have someone achieved good resaults with thermite( i mean melting hard steel targets) is it good to mix the thermite with some Sulphur and pressing it when hot?

[kingspaz]

i think this is one of the other myths of thermite. you need ALOT to cut through thick steel targets. you also need to design how the molten iron is applied. you need it to drop down onto the target from a height to cut things properly. i think a crucible with a hole in the bottom would work best. thats how they use thermite for repairing cracks in railway lines. i'm sure the same principle could be applied if the thermite where to drop onto a sheet steel target. the heat of the molten iron will melt the steel and the force of more molten iron landing on top will push a hole through.

[Sparky]

Yes, kingspaz you are absolutely right.

Simply RED: One of my friends has had widely varying experiences with ferroaluminum thermite. First he tried normal rust and painters grade aluminum (75/25) and it would not sustain combustion. He thinks it may have been because he used salt in making the rust. Sodium chloride takes a lot of energy to decompose. Perhaps hydrochloric acid would work better to catalyse iron to iron oxide transition. Even when the rust was washed he found that it did not work very well. He has read that rust contains many different iron oxides and impurities, and simply does not work well for thermite. He suspects using bought red iron oxide or making it through one of the methods in the "making iron oxide" thread would work much better. My friend also tried burning fine steel wool to get black iron oxide. The thermite made with it burned vigorously but was unable to melt through even the thinnest steel. He has had much better results with ceramics store bought black iron oxide and indian blackhead aluminum with some 80-100 mesh aluminum. A pile the size of a quarter can easily melt through a concentrated juice container can top which is less than one mm thick (Woohoo!). I asked him and he thinks that using a binder with the thermite would be a good idea if you were using it for anything serious as thermite can be awkward to work with especially since it needs a first fire and all.

[kingspaz]

hey, thats given me an idea!
if a block of thermite could be cast and ignited from the middle of the base, between the thermite and the target. it would be much more effective as the molten iron wouldn't be able to escape to the same extent and so build up ontop of whatever it is on instead of showering away.

[Flake2m]

I also know that you can use CaSO₄ in thermite mix. CaSO₄ is also used in plaster of plaris. Couldn't you cast a block of plaster of paris with some Mg or AL mixed in?

That would make it easy to transport, and besides no-one one would suspect a thing if you are found carrying a few bricks <img border="0" title="" alt="[Wink]" src="wink.gif" /> .

[nbk2000]

Castable plaster/metal incendiary is an old idea from the Black books. I made one, so I know it works, but it burnt up in a few seconds.

Now, if you made regular thermite, and used just enough plaster to bind it into a block, then you might have something. Drill a hole half-way through the block, fill with igniter, then firmly attach it to the target so it doesn't jet off. That should be enough to cut through the target.

[xoo1246]

Pressing the thermite with a hydralic press would turn it into solid block. But seriously(as allready said, but I wish to stress the fact), a thin tubing with thermite will accomplish no cutting effect. Only igniting flamable object and doing som pitty little welding.

"While the Frankford Arsenal design has merit, and a 1.5 pound(680 grams ) charge of thermite could penetrate 1 inch thick steel plate, it is still insufficient with respect to thermite mass efficiency, to produce reasonable penetration levels. These devices also require the large void air space within the device cavity which makes the device too large (3" diameter.times.12" height), approximately four (4) times larger in size over the current system, AN-M14. Furthermore, the device requires means for locking the device onto a target. "

And if you use a design(similar to 2,253,364 ) where the molten reaction products flow freely from the casing onto the target, there is a great chance you will end up with the target and a large metal blob welded to the surface of the target(atleast that's my experience with normal thermite).

"However, because of the great difficulty in igniting aluminum/iron oxide mixtures and the almost complete absence of gaseous reaction products, which causes flameless burning and a small radius of action of the hot thermite, aluminum/iron oxide is not used alone as an incendiary mixture. It is used in multicomponent thermite incendiary compositions, in which another oxidizer and binder are together included. THERMATE-TH3, a mixture of aluminum and iron oxide and other pyrotechnic additives, was found to be superior to aluminum and iron oxide alone and was adopted for use in incendiary hand grenades. Its composition by weight is aluminum/iron oxide 68.7%, barium nitrate 29.0%, sulfur 2.0% and binder 0.3%. The addition of barium nitrate increases the thermal effects, creates flame in burning and reduces the ignition temperature"

This or similar composition can be used in an core burning device where the generated gases push the hot metal particles torwards the metal targets(as described in patent 5,698,812). Another idea could be
filling a very thin metal pipe with hard pressed slow burning thermite. Igniting the thermite in the end and pressing the device agains the target(preferably with a long handle).

Edit: Oups, missed your post there NBK.

<small>[ December 17, 2002, 01:41 PM: Message edited by: xoo1246 ]</small>

[nbk2000]

I'm thinking that, in thick targets, the thermal mass of the metal will drain away the heat of the molten metal as it impacts on it, causing it to cool and form a slag blob that protects against further damage from the following molten metal from the thermite.

What may work better would be to have a two stage incendiary. The first stage is an aluminum/plaster jet to cause intense localized heating of the target zone, as well as some pitting, followed by the thermite slag.

The slag will then continue the heating of the target that was started by the jet, without losing any heat in the process of bringing the target up to its melting point.

[Sparky]

This is a little close to cross posting for comfort but oh well.

There was a post by Donald Harmann on rec.pyrotechnics that talks about sulphates in pyrotechnics. I posted the entire article in the flash powder thread, but I know some people read only seleted threads, hence this post. I found this particular part of the article relevant to this discussion:

Calcium sulfate: Despite the many obstacles noted above,
calcium sulfate hemihydrate (plaster of Paris) [CaSO4-
1/2H2O] has been used as an oxidizer in fireworks and
pyrotechnics: In combination with sodium and barium nitrate
in white light compositions (Ellern, 1968, formulas 36, 37
and 38), as an incendiary when combined with aluminum (US
Patent 2,424,937, Vol. 3 of the "Black Book", 1982), or
aluminum and magnesium sulfate (US Patent 4,381,207), and
when compounded with aluminum, Teflon, and sulfur (US Patent
4,349,396) as a metal cutting torch.

(Emphasis added)

I checked out the patent an it seems like a viable torch, but not stellar.

[pakostnik]

3Cr2O3+6Al+2C
t = 6500 K
I'm think this is the best thermit
Mg+(CF2)n
4000 K
In one book I saw that thermite :Zr+Pb3O4
But IMHO this thermite can to blow up

<small>[ January 11, 2003, 03:39 PM: Message edited by: pakostnik ]</small>

[vulture]

Zirconium has the highest flame temperature of all metals at 4600C, but it's hard to acquire and expensive. Al + Pb₃O₄ is used in crackling stars and mixtures with stronger reducers might very well be explosive because it is quite a good oxidizer at high temperatures.

6500K seems awfully high, that's more than 6300C. I would be surprised if that can be achieved with that mixture because the gaseous CO₂ would drain alot of heat.

[Sparky]

nitpick: 6500K is about 6227C

While I'm sure Al + Pb2O3 is very vigorous, the formula for dragons eggs is more complex:

'Dragon eggs' star (Crackling star)
Source: rec.pyrotechnics. Composition from "The best of AFN III"[12], page 121
Comments: Sometimes, Bi2O3 is used instead of Pb3O4. The composition is extremely sensitive, both to friction and impact. It is also quite poisonous and explosive. Gloves and an air mask must be worn at all times when handling this mixture since the mixture contains the very toxic Pb3O4.
Preparation: Add lacquer untill the thickness is like wood putty. Pass the mix through a screen and dry it to make 1mm squares. These will explode with a sharp crack shortly after lighting and can be used as star cores.

Pb3O4............................................. 81.8
Magnalium (50/50, 100-200 Mesh)...................9.1
Copper(II)oxide................................... 9.1
Nitrocellulose lacquer binder.....................10% by volume

Another point:
I thought until recently that "thermite" referred to any metal oxide being reduced by a more active metal. But as shown in a recent discussion on rec.pyrotechnics, this seems not to be the case.
Supposedly Goldshmidt (sp?) specifically named the red iron oxide + aluminum reaction thermite when he discovered it. The other similar reactions are just called "Goldshmidt reactions".

I have no doubt that the mentioned zirconium reaction would be very fast burning :D .

[chemoleo]

On the note of exotic thermites - recently a stoichiometric mixture of CuO (commercial) plus Al (200 mesh) were tried. Around 300 g (combined) were prepared. The first test was to see how it would deflagrate. CuO/Al proved to be the most sensitive thermite I ever tried, even more so than MnO2/Al. It ignited/deflagrated by a simple spark of a sparkling candle, and the heat of a burning piece of paper was enough to set it off. Deflagration occurred (despite a line of the mix) instantaneously, i would say along the lines of a primary explosive - basically instantaneous, producing a whoosh type of sound similar to HMTD
A small amount (ca. 10 g) of this liberated a large pressures shock (could be felt 10 m away, on clothes), and left the plate on which it was ignated in pieces. Copper globules were found on the surrounding snow and plate.
Next, a larger amount was confined (200 g,easily achieved because the density of the mix is so high), in two metal cans (0.4 mm thickness). This resulted in a very very loud explosion, which was in fact the loudest I ever heard from 200 m away. It left a massive copper cloud, plus copper globules sprayed onto the snow in 4 m diameter. Fragments of the cans weren't found at all.. despite searching :(
Anyway, I just report this to point out the force/sensitivity of this particular thermite - it is indeed very sensitive, and does not compare at all to the more common ones, such as Al/Fe2O3.

[Crazy Swede]

Pakostnik,
What is your reference for the temperature of the Cr2O3/Al/C system you mention above?

To quote Ellern:
"Since between 5500 and 6000 degrees K one reaches the limits of chemistry, this also means that pyrotechnically-created heat cannot rise above this limit."

[chemoleo]

Crazy Swede:

According to Fischer's and Grubelichs 'A survey of combustible metals, thermites and intermetallics for pyrotechnic applications' it states that the reaction 2 Al + Cr2O3 produces an adiabatic reaction temperature of 2789 K (w/o phase change), and 2327 K with phase change. Admittedly it leaves out carbon, but I doubt that this would make such a HUGE difference. The 'with phase change' is probably more applicable in most cases.
The hottest thermites, with phase change, that I could find in that very exhaustive list are 2 Be + PbO2 (4123 K), 2 Hf + Pb3O4 (4410 K), 2 La + 3HgO (>4473 K), 2 La + WO3 (4367 K), 10 Nd + 3 I2O5 (<7580 K !!!!), 10 Y + 3 I2O5 (>4573 K)... Unfortunately these metals aren't exactly common ones.
In terms of energy (-Q, in cal) per gram of Al - based thermites, Al/MnO2 is at the top of the list (1159 cal/g), followed by Al/MoO3 (1124), Al/V2O5 (1092), Al/CuO (974) and Al/Fe2O3 (945).
So... Al/CuO and Al/Fe2O3 rank pretty high in terms of energy released, but are surpassed by some harder to get thermite mixtures.

PS I do have that file as a pdf (1.4 MB), so email if you want it.

[Bert]

chemoleo-

There was a US manufacturer who actualy used to use CuO/Al mixes for flashpowder in aerial salutes. As you noted, you can get a LOT in a small case, compared to even KClO4 flash. They stopped after they had an accident with fatalities. Apparently, this mix is particularly sensitive to ignition from static discharges. Be careful- If it's low humidity, in particular. Use disipative grounding, anti-static spray, etc.

[Dave Angel]

Ah I'm glad the topic of thermites came back up, I'd forgotten I intended to make some.

Having a look at ceramic suppliers, it seems manganese dioxide, (which I read in another thread makes thermite that spits less), is actually LESS expensive than black iron oxide! Red iron oxide remains the cheapest but only by about £1 per 5kg.

[Bert]

Aluminum/Manganese dioxide (ALMAD) will function as a rocket propellant... The exhaust is Manganese gas, which afterburns in the air. These will fry your eyes to watch- Very bright flare and a black smoke tail. It takes thermolite or similar to reliably ignite these engines, however.

[Dave Angel]

Thanks Bert, thats useful to know. I might try it out for that very purpose then. Maybe it could be cast with CaSO4 and drilled to make propellant cylinders but I'm just guessing here. With the oxides not being all that expensive I may buy a few and experiment sometime.

Speaking of bright flares, it probably seems obvious to members who already have them, but welding goggles are very useful when it comes to observing such things, and they aren't all that expensive.

[chemoleo]

DaveAngel- on the note of 'spitting' thermites, I found that only Fe3O4 produced this effect (plus a comparably slow reaction). However, this oxide was not a fine powder but often small 0.5 mm grains, despite it being a commercial pottery product. Conversely, Fe2O3 burns without spitting (powder grade Fe2O3, and 200 mesh Al), while MnO2 behaves pretty much the same way - i.e. it burns a little faster than Fe2O3, but no spitting again.
Conversely, I found that grain sized Al or even large Al filings/scrapings (up to 5 mm in length) produced lots of spitting with the very same Fe2O3. Hence I have come to the belief that spitting is more a function of the particle size, rather than the particular oxide used....

PS Pls check your email.

[scarletmanuka]

That rocket proppelant sounds very interesting Bert. Do you know if it is an end burner or core burner. Do you think it would be handy in small say 1 or 2 gram grains. I have played around a lot with MnO2 and Al, and it does burn reasonably fast.

[Bert]

Press it in a core burning engine similar to the dimensions used for black powder- ISp is similar, it will erode the nozzle more than BP though. It will also usualy set the rocket stick on fire, so be careful where you shoot these. One problem with these, the fuel constituents are very different densities, so only mix what you're about to load or the fuel may settle and separate.

[Blackhawk]

That sounds really interesting, I would make it but for the moment BP is easier and cheaper. But for the record would the MnO2 from dry cells be of sufficient quality to use?

EDIT: (woo, finally reached 100)

[Dave Angel]

Well chemoleo I guess you've proved that experimenting is the only way to find out if something you read or theorise about is nonsense or not!

IIRC, MnO2 from batteries contains a fair bit of carbon powder. I tried to remove this once a while back by heating and blowing air over it but the mixing wasn't very good and the powder just ends up going everywhere.

I should think that it's possible though, heating in a closed crucible type affair with a stream of air fed in and a pinhole to allow the gases to escape, hopefully without too much MnO2 escaping.

[Bert]

I've never tried extracting it from batteries, I allways got mine from ceramics suppliers. It's a very cheap chemical.

[Mumble]

If you react the battery powder with HCl to make soluble MnCl2 and solid carbon, you can easily filter the carbon out. Convert the MnCl2 to the sulfate or hydroxide and heat to decompose back to MnO2. This may be more trouble than it's worth. As Bert already mentioned, it is not an expensive or rare chemical.

[nbk2000]

The exploding copper thermite mix would be very useful of powerline sabotage.

Make a simple pipe mortar (placing the mortar under the wires), measure the lifting charge so that the can of your thermite is lifted just above the lines, with the fuse cut to explode it either in the wires or just above, so that the cloud of copper dust causes the electricity to arc between the lines or to the tower.

Since the arc distance of the high tension lines is just a little less that the length of the insulators, if you produce a cloud of highly conductive copper vapor of sufficient size to cross that distance...lights out!

And, since it's the main lines bringing the power in from the dams, you'd black out whole sections of a city, rather than just one part of the block.

With no visible damage like collapsed towers, broken insulators, etc., it's entirely possible that'd it initially be written off as natural causes (lightning, whatever). This assumes you take the expended mortar tube with you. ;)

[vulture]

DO NOT USE MnO2 from batteries for thermite! MnO2 from batteries is severely contaminated with KOH, needless to say this would be very dangerous with Al or Mg!

[T_Pyro]

KOH? In a dry cell? I think you're talking about alkaline batteries. The common dry cell contains only MnO2, Zn, NH4Cl, graphite, and traces of Mn2O3.

[vulture]

Yes, I was talking about alkaline cells. NH4Cl with metal powders is no good either. Dry cells are pretty rare over here.

[Third_Rail]

NBK, after experimenting with the amounts needed for a good size cloud of copper particles, about 200g should do it for high tension powerlines, that is, if they're all built the same and not just the kind I was basing my research on. Getting a charge of CuO/Al thermite to initiate at exactly the right height is quite a pain in the ass, though; you have to have the charge so it first goes above the lines and goes off about 2m above them, which is not an easy task at all since wind and weather conditions can quickly piss your plans away.

[Blackhawk]

Wouldn't it be easier to have the charge tied to a lot of helium balloons? You could take a tank of helium and a pack of balloons in the back of a car and simply have them tied to a long string tethered so the charge remains at exactly the right height.

[NightStalker]

Or attach a wire to two ballons that are on opposite sides of the powerline, and let them go to float up into the powerlines.

But where's the fun in that when you can blow something up instead? :p

[Blackhawk]

Well if you used the balloons and the charge you still get the fun of blowing something up, and there would be little evidance afterwards, but it would be a hell of a lot more reliable than attempting to get a mortar round to blow at exactly the right height (within 1 foot or so).

[apathyboy]

Or you could just use a non conductive string like monofilimant for fishing, attatch a weight, and lob it over the powerline. Tie on your charge, light a good bit of fuse, hoist the charge up to the line, peg down your extra string with a U nail or tent peg, and run away giggling.

Actually, if you used a rock to pin down the extra string and retrieved the weight on the end of the line before lighting the charge, the only traces left behind would be (potentially) case fragments and a severly melted bit of fishing line, not a lot of evidence to go on.

If the idea of tossing any kind of cord over a high tension wire sounds ridiculous, well, it's 3 in the morning, and just about everything seems reasonable to me right now.

[kingspaz]

apathyby, you're right. IT IS RIDICULOUS!

non conductive doesn't mean it won't conduct, it just means it conducts with difficulty ;)
from a quick search it seems most powerlines are over 100kv = anything will earth them.

[nbk2000]

Having recently gone through several hundred PDFs and PPTs downloaded from a .mil site (with many hundreds more to go...), and picking through to find the gems, I've gotten an interesting concept from one of them.

Reactive material fragments and bullets.

These are normally inert materials that, when subjected to impact shock and compression, react in a violent manner that is destructive to the impacted target.

For instance, a .50 cal bullet that is composed almost entirely out of a compressed core of reactive materials enclosed in a copper FMJ. You can whack it with a hammer, or run it over with a tank, or saw it open, and it'll do nothing.

But, shoot it into a drum of diesel fuel or a SCUD missle, and BOOM! This is because of adibatic compression and impact shock heating the materials to their reactive temperature.

Now, what does this sound like? Sounds a lot like CuO/Al thermite, don't it? When subjected to shock, it reactives explosively, with great heat. Otherwise, it's pretty inert stuff.

Now, how to form it into fragments that'll survive explosive dispersal, as is being done with AAA warheads...

Maybe compressing the mixture into sections of steel tubing, like star mix, and using a shock attenuating material like rubber sheeting interposed between the fragments and the explosive?

The Big Boys are managing it somehow, as the arena test pictures clearly show that the fragments are NOT burning on their way to the target, only exploding upon impact.

[999]

Connecting a wire between powerlines will do nothing as they are all at the same potential. Even grounding the powerline with a wire is likely to be ineffective-the large currents flowing throught the wire/conductor to ground will cause a massive localised release of heat that will probably damage the conductor, thus rendering it ineffective.
A much thicker conductor (or possibly wider) would be better. Due to the skin effect, a metal drainpipe stood up and left to fall against the powerlines is the easiest way to achieve the effect previously talked about.

Remember those adverts as a child with kites and powerlines combined? The child is electrocuted but you don't hear about powercuts due to this do you?

[Bert]

Now, how to form it into fragments that'll survive explosive dispersal, as is being done with AAA warheads...

The Big Boys are managing it somehow, as the arena test pictures clearly show that the fragments are NOT burning on their way to the target, only exploding upon impact.

Can you give a link to the pictures/video of this? Might help figure it out- And I allways like a nice explosion video.

[Rosco Bodine]

Having recently gone through several hundred PDFs and PPTs downloaded from a .mil site (with many hundreds more to go...), and picking through to find the gems, I've gotten an interesting concept from one of them.

Reactive material fragments and bullets.

These are normally inert materials that, when subjected to impact shock and compression, react in a violent manner that is destructive to the impacted target.

For instance, a .50 cal bullet that is composed almost entirely out of a compressed core of reactive materials enclosed in a copper FMJ. You can whack it with a hammer, or run it over with a tank, or saw it open, and it'll do nothing.

But, shoot it into a drum of diesel fuel or a SCUD missle, and BOOM! This is because of adibatic compression and impact shock heating the materials to their reactive temperature.

Now, what does this sound like? Sounds a lot like CuO/Al thermite, don't it? When subjected to shock, it reactives explosively, with great heat. Otherwise, it's pretty inert stuff.

Now, how to form it into fragments that'll survive explosive dispersal, as is being done with AAA warheads...

Maybe compressing the mixture into sections of steel tubing, like star mix, and using a shock attenuating material like rubber sheeting interposed between the fragments and the explosive?

The Big Boys are managing it somehow, as the arena test pictures clearly show that the fragments are NOT burning on their way to the target, only exploding upon impact.

NBK ,

What you are decribing sounds like a "pyrophoric penetrator" .
The core is sintered zirconium powder which ignites from the
heat of impact imparted to the fragments which then inflame
upon contact with the oxygen of the air . Those rounds are
an alternative to spent uranium 40 mm "tank killer" rounds
like the warthog uses to take care of armor . The concept
has been used for other calibers too .

[Boomer]

kingspaz: An insulator will NOT ground the wire! Even the 400 kV lines have to be fixed somehow, remember? Those ceramic insulators work with only a few metres lenght, so a (dry) plastic string will be safe if thrown from the ground. Newer insulators are of plastic (glassfibre/silicone rubber) anyway.

999: Connecting a wire between powerlines DOES work! For a 400.000 Volt line, the voltage between each two of the three wires is 400kV, the voltage from each wire to ground is 230kV. Guess why there are always 3, 6, 9 or 12 wires (plus earth on top)? It is 3-phase current.

You are right that a thin wire will melt and stop the short, but if it bridges the ceramic insulator the arc will keep burning until some overcurrent switch cuts the power. The ceramic insulator might even crack from the heat. :D

BTW it is much more effective to shoot at the ceramic to bring the wires down! If you want a delay, place a small charge on the insulator (near the grounded side!) to break it. But I would use a chemical delay, no electric firing - we speak of 20.000 Volts per metre electric fields up there...you can climb up and have a (harmless) arc burn from the tip of your nose. Really, I tried! :p
(After some years of high voltage engineering at university)

[nbk2000]

Finally got around to getting the picture of the arena test of a reactive fragment warhead.

No video, I'm afraid, even though I asked. Rude bastards! :p

[tmp]

Boomer, you're correct about shorting between high voltage powerlines.
During Gulf War I, the military fired Tomahawks with a special carbon-filament
dispersal warhead. Its only purpose was to lay these filaments across the
high voltage lines leading into Baghdad, trip the main breakers, and at least
temporarily cut power to the Iraqis' early warning radar grid.

It seems this thread has drifted a little. But back on topic. I don't know the
burning temperature, but Cr2O3/Mg thermite burns fiercely with a light more
intense than I ever saw with any Fe/Al mix. Just an observation. NBK, nice
picture of that reactive ammo !

[Gumby]

It seems this thread has drifted a little. But back on topic. I don't know the
burning temperature, but Cr2O3/Mg thermite burns fiercely with a light more
intense than I ever saw with any Fe/Al mix. Just an observation. NBK, nice
picture of that reactive ammo !

That depends a lot on the powder being used. If you want a violent thermite reaction look into Al/WO3. Al/Fe mixtures can be made to explode rather than burn. In theory an Al/Fe mixture will put out more energy than a Cr2O3/Mg mixture. WO3 out performs both of them, but it is even harder to start that Al/Fe2O3.

As for the copper to high voltage line idea... I wouldn't want to be the one who had to test that theory. Having used high voltage tesla coils (180kV) there is a noticeable build up of static electricity in the air near such power sources... copper thermites are extremely electrostatic sensitive. Also consider that a copper thermite will not explode as well as you think, as soon as those particle come apart from each other the reaction stops which makes it a poor explosive, also because of this it doesn't completely react all of the copper oxide into pure molten copper. Nanopowders would be the exception to this as the reaction could be complete in a matter of a few thousandths of a second.

[bluetuniclink]

Back to the exotic mixtures, I found a site that focuses on thermite and its many forms. Go to www.amazingrust.com (http://www.amazingrust.com/Experiments/how_to/Thermite_pics-videos.html#Fe3O4). Although the other mixes can be more energetic, I stick to the Iron/Aluminum kind because of the price.

[Controlled Chaos]

According to a demolitions expert by the name of Torin Wolf, there is another thermite that he refers to as "Super Thermite". First he explains that if sulfur is added to the traditional Iron Oxide/Aluminum thermite then this creates Thermate. He says Thermate is used in heavy demolition. He then goes on to describe this "Super Thermite" made from adding potassium permanganate (KMnO4) and cupric sulphide (CuSO4) to Thermate. He states this "Super Thermite" is explosive and used for mega-demolition.

Wikipedia yields the following composition for Thermate-TH3: 68.7% thermite, 29.0% barium nitrate, 2.0% sulfur and 0.3% binder.

Has anyone ever heard of the "Super Thermite" described by Torin Wolf? If so, What are the percentages or ratios of the composition? Would Thermate-TH3 possibly make a better "Super Thermite" than using a Thermate(thermite/sulfur only) mix because of the barium nitrate used? Torin doesn't speak of the barium nitrate being used in the Thermate that he describes.

Link: http://nationalwriterssyndicate.com/index.php?option=com_content&task=view&id=128&Itemid=2

[Cindor]

He then goes on to describe this "Super Thermite" made from adding potassium permanganate (KMnO4) and cupric sulphide (CuSO4) to Thermate.

Cupric Sulphide (Copper (II) Sulphide CuS) or Cupric Sulphate (Copper (II)Sulphate CuSO4 ) ???

One is a fuel and the other one is an oxidizer, there's too much difference among them.

[Controlled Chaos]

I guess thats a pretty good question Cindor. That was copied Directly from the source. So this may have been a typo or complete BS. Anyone have any other ideas about this "super thermite"?

[cracker]

The evidence that has been analyzed of the World Trade Center was said to contain traces of a Potassium Permanganate Thermite.

I, too, would be interested in hearing more about this Formula

[NoltaiR]

Ok, completely off topic question here:

I was reading through this and for the first time I actually took notice of NBKs profile image. Is that the alien from Alien Vs Predator?

[Jacks Complete]

NoltaiR, it's his passport photo.