Talk:Thermite

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[edit] Making Thermite

I fail to see why "How to make thermite" is relevant to this article. It seems to be encouraging individuals to make some for themselves. Without a strong disclaimer, how can this be permitted?

[edit] Stating the temperature of a thermite reaction is scientifically incorrect

Technically a reaction releases energy, which in turn can be used to change the state of the reactants. To say that a reaction has a certain "temperature" is misleading: the actual temperature depends on the ambient temperature, rate of heat loss, etc. Nonetheless, it is nice to put in some numbers for average conditions so Mr.Layperson gets a feel for how powerful this reaction is without doing any math.

~Not only is this temperature statement misleading, but the way it is used within the article is on the matter of igniting thermite with a magnesium strip by way of the flash burn point. The problem here is it is listing the temperature at 2500K (4000F) and the flash burn point of magnesium is 8000 degree Fahrenheit.~

[edit] dictionary.com claims that it is thermit (without final e)

I spell checked the article of aluminium and the word thermite was non existing. To find out whether it was correctly spelled I looked it up at http://www.dictionary.com . This is the info dictionary.com gives:

"Thermit

A trademark used for a welding and incendiary mixture of fine aluminum powder with a metallic oxide, usually iron, that when ignited yields an intense heat."

So nothing about thermit as a name for certain chemical reactions, just that a brand name of such an chemical mixture is "thermit", without final e. Is dictionary.com wrong or Wikipedia? Or is the brand name "thermit" and the name of the chemical reactions "thermite"? If you'd find out that dictionary.com is wrong please leave a note saying so on this talk page. Tx in advance for looking this up. --Paulus/laudaka (add me to your YIM/AIM/ICQ/M$N M contact list if you like!) Laudaka's talk page 21:30, 12 May 2004 (UTC)

Merriam-Webster Online lists a substance called 'thermite' and a trademark called 'Thermit'. Issue resolved? --Smack 21:07, 20 Aug 2004 (UTC)


[edit] Thermite/Thermit discussion

"Or is the brand name "thermit" and the name of the chemical reactions "thermite""

Yes, the brand name is 'thermit' and the reaction is a 'thermite' reaction. --Anon.


[edit] Other Thermites

Is this a forum sorta thing? i am not sure... someone correct me please... well my question is could one make a thermit mix from aluminium and some other oxide...like howabout copper oxychloride?

Yes, a thermite reaction is simply a reaction involving a reactive metal and the oxide of a less reactive metal. Basically you can use any reactive metal, and any less reactive metal compound containing oxygen. Aluminum and rust are simply the most used, since they are more readily available.
And as I understand it, they release quite a bit of energy. I hear that copper/aluminum thermites are used in armor-piercing missiles though, so perhaps they have a greater ionization energy (is that the right phrase?). --Maru (talk) Contribs 23:15, 26 October 2005 (UTC)
Yes, cupric oxide/aluminum thermites typically attain a temperature that is above the boiling point of copper, which results in a gaseous product and an explosion. For this reason, such thermites with low boiling point metals involved are used less. Other mixes that will explode include ones that use zinc as the reducing agent or lead oxide (Pb3O4 or PbO) as the oxidizer. These mixtures also have high enthalpies of reaction.
Ionization energy isn't really relevant to this though, since Ionization energy is just the energy required to pull an electron off of an atom (or ionizing it) and there is no ionization in this reaction, it just produces an extreme amount of heat during the reaction. Helgers7 06:35, 17 March 2007 (UTC)

[edit] Thermite Process (Ames Process)

So is the thermite process just the function of using thermite? Or, as I think, something different (but involving aluminium...)? This is not clear from the article, but the redirect from Thermite process is indicative that it might be.

[edit] Making Thermite

Should there be a section included on making thermite? I've performed small reactions myself, and they've always been very exciting to do. If the correct measures are taken, it's a very safe procedure because the material won't explode under normal conditions and it is nearly impossible to accidently ignite it. Further more, powdered iron oxide and aluminum are easily and legally obtained from online retailers like ebay. --Daveswagon 00:36, 17 Jun 2005 (UTC)

The article already mentions the weight percentages for mixing thermite from powders, but that information could be moved to a ==Production== section or something like that. As far as making the raw ingredients yourself (with household items), I tried and failed, but it may be possible. I would tend to leave out any instructions about getting rust from nails/rulers/etc unless someone has first hand experience and it does in fact work. --SCEhardt 04:11, 17 Jun 2005 (UTC)
I'd just like to point out thermite does indeed have quite a few dangers. True, there is basically no chance at all of it igniting unintentionally, but when it does ignite it is a powerful energetic material that can easily harm the unwary. A few particular points:
  1. Explosions are in fact possible. The two main ways these can occur are due to pockets of moisture in either the ingredients, the crucible or anything the melt spills onto; or contamination of the ingredients with relatively volatile metals (e.g. zinc or zinc oxides). In the first case you get a steam explosion, in the second case the thermite reaction reduces the metal oxide but the metal is produced as a gas rather than a liquid. Either way, you get gobs of molten iron being thrown violently out. To avoid this, you need to be sure your ingredients are scrupulously dry, and at least moderately pure (a problem if you are making it from scrap metal). If it is going to spill onto the ground, make sure the ground is also very dry.
  2. Even with some care taken to avoid volatiles, it is not uncommon for "spattering" to occur, small amounts of molten iron being thrown by traces of volatile contaminants. (In foundry and welding operations, much more severe, but still nonexplosive, spatter is also caused by overheated apparatus collapsing or dropping weights into the melt.) Consequently all flammable materials should be removed for a radius of several metres, and spectators should watch either from a safe distance or through a lucite screen.
  3. Speaking of spectators, the high temperatures involved can produce quite a bit of UV light. To avoid retinal damage observers should either be placed so that they cannot directly view the core of the reaction, or else should wear welding goggles. Other useful accoutrements for the demonstrator are elbow length heavy leather gloves, and a heavy leather apron which goes down below your boot tops. If the apron doesn't cover your boot tops then leggings are a good idea too. (The last thing you want is some molten iron getting into your boots.)
  4. Never do this demonstration above anything you would not risk igniting. I saw a demonstration years ago where the melt ran into a crucible embedded in a sand filled terra cotta flower pot sitting on an asbestos sheet on top of a lab bench. This may have seemed like adequate precautions but it was not. Due to some miscalculation the crucible overflowed, the iron somehow found its way through a crack in the baked sand to direct contact with the pot, from thermal shock the pot cracked, and collapsed, overturning the crucible, and there was enough iron present to run right off the asbestos sheet and set fire to the bench. Oops.
  5. No-one should ever attempt a dangerous demonstration without a plan for what to do if it goes wrong. In this case, that means fire-fighting and first aid. However, unless you have access to Class D fire extinguisher, the only safe fire-fighting material is very dry sand, applied with a longhandled shovel. Obviously it will not extinguish the thermite but it will stop fire spreading into surrounding material until the thermite burns itself out. If you do get a thermite fire going and don't have any sand available, do not attempt to fight it. Just get everyone to safety and when the fire brigade arrives, make sure they know there's burning metal involved. --Securiger 09:08, 17 Jun 2005 (UTC)
This information should be added to Wikibooks: Thermite synthesis. --Yannick Gingras 06:52, August 28, 2005 (UTC)
Yeah, I was aware of the risk from moisture. I've heard that thermite can supposedly dissociate the hydrogen from water and ignite it- not an ideal scenario. As for making the materials from household items, I'd say that's an exercice in futility. Getting a fine, dry, pure powder from rusty nails/steel wool or filed pop cans is unlikely. I learned that the hard way. --Daveswagon 00:51, 19 Jun 2005 (UTC)
Oh trust me it works. Made it in 8th grade off the Anarchists cookbook. Tore up the sidewalk like hell. Used a DC trainset transformer, salt water, etc - Anon
It does burn very hot; when I made some, the dirt where it had been ignited remained burning for a few seconds after the thermite had gone out. The dirt had been turned to charcoal by the heat. As to making it with household materials, one source of fine aluminum powder is silver spray paint. The aluminum powder can be washed from the paint with acetone or paint thinner. As the above user mentioned, iron oxide can be prepared electrolytically (and then dried in an oven). As to thermite separating hydrogen from water, the aluminum does this. It's actually a kind of incomplete thermite reaction. The equation is: 2Al + 6H20 => 2Al(OH)3 + 3H2 -- Anon
Yeah, i made some according to the information avalable in the anarchists cookbook. the ratio is (i think) 8FeO:3Al. Could be wrong. It burnt like a bitch, i tryed it out in my garden and it went through brick. Quite spectacular. —The preceding unsigned comment was added by 82.3.78.35 (talk • contribs) .
I think it would be extremely unwise to post how to make thermite on here, being as how the ingrediants are relatively simple to obtain and the reaction is quite dangerous when performed by someone who isn't trained to handle it. I've seen thermite rip the oxygen out of dry ice (CO2) to continue burning, so it's not at all easy to "put out". In any case, the last thing that needs to happen is a bunch of kids being badly injured or worse becuase of instructions they found on here. Helgers7 06:36, 17 March 2007 (UTC)
Added a disclaimer section, saying that the info is for informational purposes only, and that nobody on Wikipedia will take the blame if you make it and injure/kill/destroy yourself/someone else/something you weren't supposed to. —The preceding unsigned comment was added by Jufam44 (talk • contribs) 03:26, 26 March 2007 (UTC).

--Kyanite 23:13, 6 July 2006 (UTC)--Kyanite 23:13, 6 July 2006 (UTC)

[edit] Aluminium and Rust?

The ingredients I have noticed is aluminium and rust, a reactive metal and a metal oxide. But how would you keep the aluminium staying just that and not oxidizing itself because aluminium is so reactive and oxidizes. So wouldnt the reaction really be aluminium oxide and iron oxide? --Anon.

No, aluminium oxide and iron oxide would not react at all. As already mentioned in the article, a key point is that aluminium forms a passivation layer, so even though it is highly reactive it remains inert until melted. --Securiger 07:56, 4 October 2005 (UTC)
Atmospheric oxidation is sometimes a disadvantage of using very fine aluminum powders in thermites, but this oxidation only occurs at high temperatures after the thermite has been ignited and then only in areas where the thermite can contact air. Also, rust is not the best ingredient for thermite because it contains a mixture of iron oxides and hydroxides (Fe2O3, FeO(OH), Fe(OH)3, etc).

The reason aluminum is used in the reaction has less to do with passivation and a lot more to do with the activity series of metals. Thermite is a single replacement reaction! In the Activity Series, alumium is near the top, bested only by Mg, Sr, Ba, Li, Na, and K. Thus, only metals that are less reactive than aluminum (lower down on the series) will have their oxide "stolen" by aluminum allowing a thermite reaction. Aluminum "wants" the oxygen from the other metal. The higher up in the activity series the other metal is (chromium, titanium, iron) the less violently the aluminum will nab the oxygen! So, Copper, being very near the bottom of the activity series, will react very exothermically with the aluminum. Iron Oxide is used because its cheap, and yields a useful product (molten iron). So to awnser the question, the aluminum cannot already be reacted, otherwise it has no reason to "steal" the oxygen from the other reactant! —Kyanite 23:13, 6 July 2006 (UTC)

[edit] Cleanup tag

I just added the clanup tag because it looks to me like it could be better worded.

I just changed it from Iron(II) oxide to Iron(III) oxide. Now I'm trying to document this and having trouble. Can someone find a reliable source for whther it shouldbe ferric or ferrous? (Sorry if I changed soemthing that was correct). RJFJR 14:29, 24 December 2005 (UTC)

I suppose ferric oxide could be used in a thermite reaction, but ferric oxide (rust) is much more commonly used. Iron (II, III) oxide (Fe3O4, magnetite) can also be used. A source is at http://chemed.chem.purdue.edu/demos/moviesheets/5.3.html, this seems fairly reliable and backs up ferric oxide.

Melt through concrete? is that possible?--XAdHominemx 21:37, 1 January 2006 (UTC)

I think this is an appropriate section for this discussion.--XAdHominemx 02:09, 2 January 2006 (UTC)
Yes, it's quite possible for concrete to melt, as was discovered during the investigation of the Chernobyl accident. Alphax τεχ 06:15, 21 January 2006 (UTC)
I thought the top was blown off by a H2 gas steam explosion... Besides, the temperatures reached during the Chernobly accident were much higher than those reached by the thermite reaction. --XAdHominemx 07:49, 22 January 2006 (UTC)
Hrm, apparantly the Elephant's foot was molten fuel, not concrete. I'll have to check up on this. Alphax τεχ 02:02, 3 March 2006 (UTC)

[edit] with sulfur it cuts throug steel faster

"with sulfur it cuts throug steel faster." I removed this senetence from the article because it was placed innappropriately in the history section, needed correct spelling and punctuation, and is unsourced. I would encourage the writer to source it and correct the spelling because if it is true, it would be nice to include. Sifaka 21:57, 31 March 2006 (UTC)


- I checked it. It is true.

[edit] Propelent

As a compleat novice, I would like to ask the brain boxs out there, is it possible to make a usable propelent out of thermit? And if it is possible, what sort of casing could contain the energy and direct the power?

Doubt it. Propellants and explosives are supposed to kick out a lot of kinetic energy, which thermite doesnae do. --maru (talk) contribs 05:51, 8 April 2006 (UTC)

Thermite cannot be used as a propellant, even though it releases an enormous amount of energy (by mass, it is one of the most exothermic reactions known). This is because none of the products of the reaction are gaseous, and propellants must release gas in order to push objects forward. Likewise Thermite is not an explosive, since the production of gases is necessary to violently burst a container.

It occurs to me that you might be able to use thermite to heat/boil water (or some other liquid), producing a gas (water vapor or whatever) which could then be used as a propellant. I'm sure it wouldn't be anywhere near as efficient as some other mixtures containing aluminum, but... --MyrddinEmrys 08:08, 15 August 2006 (UTC)
At high enough temperatures and pressures, thermite would fission or fusion and produce sufficient energy to propel an object, even without gas released :) --Froth 22:45, 22 August 2006 (UTC)

Actually, I believe I recall the show Mythbusters referring to it as a rocket fuel.

[edit] potassium chlorate and peanut butter

citation is definately required on this one - while potassium chlorate is a strong oxidiser (http://en.wikipedia.org/wiki/Potassium_chlorate) I'm not sure that ypu'd be doing much more than burning peanut oil here - not really a reaction in the same category as the thermite reaction—The preceding unsigned comment was added by Peterxyz (talk • contribs).

Regarding peanut butter, I think the idea was to use it to ignite the thermite, but I don't know whether it actually works. Also, we don't need to list every possible way to ignite thermite, just the common ones. -SCEhardT 22:27, 17 June 2006 (UTC)

I routinely use the peanut-butter method to ignite thrmite. Chlorates are such powerful oxidizers that they will react violently with any easily-reduced substance. I invented the method when wondering how to ignite a kilogram of the stuff, after having failed with magnesium. I simply went to Safeway and examined the caloric contets, per gram, of various foodstuffs, assuming that a higher calorie concentration cooresponded to a greater amount of chemical potential energy available. Since the human body oxidizes substances just like chlorates will (though much more slowly and in a more controlled manner), this made sense. Jif Creamy Peanut Butter contained the most fats and sugars and so on, so I bought it, rolled a teaspoon in KClO3, and kneaded it like a roll of bread. It worked perfectly. The substance might well be a high-order explosive if triggered by a suitable detonator. That isn't an experiment I amn going to attempt. But overall I recognize that my own experience does not constitute a verifiable source, so I will hold off on describing the peanut-butter method until I get a book published ;-).

[edit] Propane

"Conventional thermite reactions require very high temperatures for initiation. These cannot be reached with conventional black-powder fuses, nitrocellulose rods, detonators, or other common igniting substances. Even when the thermite is hot enough to glow bright red, it will not ignite as it must be at or near white-hot to initiate the reaction. It is possible to start the reaction using a propane torch if done right, but this should never be attempted for safety reasons." A common detonator such as a blasting cap burns hotter than propane. Dudtz 6/20/06 7:45 PM EST

Blasting caps are designed for setting off a detonation in explosive materials, however. The powder nature of Thermite would cause the material to spray everywhere rather than achieve the desired effect. From what I understand, the fuses in thermite grenades activates a magnesium igniter. A blasting cap is itself an exposive device meant to initiate detonation within military-stable explosives such as C4, which require both heat and pressure to activate. - Steelcobra 04July06, 0615 EST
Supposedly cupric oxide/aluminum thermite can be set off by a blasting cap or a gunshot; I have seen videos of both. However, this type of thermite often proceeds with reactants and products in the gaseous phase, as opposed to liquid with conventional (iron oxide) thermite. --24.16.148.75 19:48, 12 July 2006 (UTC)


C4 does not conduct electricity. As a secondary explosive, it is set off by a blasting cap. The blasting cap is often ignited with an electrical ignitor. From the article on C4, "The only reliable method for detonation is via a detonator or blasting cap." --24.16.148.75 19:48, 12 July 2006 (UTC)

[edit] disabling artillery

Informative but inappropriate, don't you think? --Froth

[edit] Corrected the mixup with iron oxides

Having used both variants, (and done the chemistry and math), I fixed the mixup in the article regarding the iron oxides. Stoichiometric thermite made from Fe3O4 is very mild compared to the one made from Fe2O3. The latter burns so hot, the white-hot iron seems almost blue. If anyone has tried thermite from FeO (which might not even burn), that would be an interesting addition to the article. Also, rust is not actually Fe2O3, but a mixture of different oxides, hydroxides and carbonates of iron. The point here is that thermite made directly from rust would yield a significant volume of gases, possibly also hydrogen, all of which - at the very minimum - could result in lower quality welding joint or cast. 130.230.101.184 10:05, 30 November 2006 (UTC)

[edit] Clean Up Jan. 2007

This article needs a great deal of cleanup and copy editing to improve its tone, remove redundant content, and remove or move trivia that dosen't contribute to the article as a whole. Please help if you can!Iepeulas 07:18, 21 January 2007 (UTC)

[edit] Difficult to set off?

If anyone else watches Mythbusters, didn't they paint a small blimp with thermite and light it? It seemed to me that the reaction too place a lot easier than this article makes it sound. —The preceding unsigned comment was added by 66.231.106.113 (talk) 07:41, 27 January 2007 (UTC).

This article is not inapropriate in any manner. Thermite making is a very complicated process any can be done in several ways. I myself have made thermite.

I'm not the best student, but I'm pretty sure I saw my college chemistry teacher take a ball of rust, wrap it in aluminum foil, and hit it with a hammer, thus initiating a thermite reaction. As far as mythbusters goes, they used both actual thermite and a dope containing unmixed thermite ingredients, so it rather depends which instance you mean. 66.41.66.213 07:28, 4 March 2007 (UTC)

[edit] Enthalpy?

The symbol for the enthalpy of a reaction is used several times in this article, yet there is no mention that that is what it is and it is simply thrown into the middle of sentences. In addition to that there seems to be a formula missing for the reaction of thermite. Helgers7 06:45, 17 March 2007 (UTC)

I am interested in the mention that the reaction in the presence of aluminum may cause the release of Hydrogen as it was mentioned that Hydrogen was released when the reaction took place under water. As with the commonly known reaction of aluminum foil and certain toilet bowl cleaners, I am interested in learning about reactions which could produce vast amounts of Hydrogen and yet be a safe and ecological means of producing it for use as an alternate energy fuel.

When I was in Junior High back in the early 60's my science instructor had made a form of 'touch-powder' which when dried upon a paper towel would react and explode when the paper towel was touched or slightly moved. I am not sure what was in it, but several of us in attempting to make it experimented in using aluminum and iodine crystals and found that if the aluminum was course enough like from aluminum being cut with a hacksaw and not a powder, that the aluminum 'sawdust' and the iodine crystals reacted when a drop or 2 of water was put on them producing a plume of purple smoke and a very intense heat from the reaction.

What has piqued my curiosity about these metal reactions is a website that I have come across http://www.cleanwatts.com where they claim to have come upon just such a reaction.

I have also hear mention that Hydrogen balloons were used in the Civil War and that the hydrogen was produced on site from some sort of portable hydrogen generator of sorts. Do we have the technology to make us independent of oil?? I for one would sure like to know.

Carcom 21:10, 17 March 2007 (UTC)

One must be careful not confuse energy generation with energy delivery. Hydrogen is easily and abundantly made by electrolysis and various chemical reactions. The big question is, where does the energy to make them come from? For electrolysis, energy from the usual places (coal, natural gas, hydroelectricity, nuclear and photovoltaics). Hydrogen is not a source, only a delivery mechanism. For an aluminum-iodine scheme, where would the energy come from? I suppose one could mine aluminum ore, reduce it (or recycle beer and pop cans), dig up or extract iodine from seawater and combine it. But it should be intuitively suspicious that the energy to obtain the materials could possibly exceed the reaction's output. —EncMstr 23:20, 18 March 2007 (UTC)
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