Sciencemadness Discussion Board

What sort of Al and Fe2O3 should I use for Thermite?

Quantum - 3-12-2003 at 20:02

I am planning to make a few grams of thermite and I want to know a few things before I start. I googled and searched the board before posting but I found little information about the Fe2O3 and none about the Al. I read that steel wool can be burnt in a steel tube and that produces Fe2O3 and that steel wool can be put in a bucket of water and the Fe2O3 extracted and dried from the bottom. Should the Al powder be super fine like when its used in flash powder? The only way I can make some that I know of is to use Andyboy's idea and blend it with water and then dry it out.

JDP - 3-12-2003 at 20:34

Fe2O3 can be made any way you want to, yet some are quicker than others. The Al powder dosnt really matter to much, the finer it is the easyer it is to light and the faster it will burn, less fine Al will make it harder to light and burn slower. I'm not to shure the people in this forum know Andyboy's Al method...;)

[Edited on 22-12-2003 by JDP]

Tracer - 4-12-2003 at 03:10

Ferric Oxide should prolly no be produced by that method, it's slow and crappy you see. Just get some Sulfur Dioxide and mix that into some circuit etchant (Ferric Trichloride and Hydrogen Peroxide). That will make a blue powder that you can let sit until it forms brown Oxide-Hydroxide. Heat that in a pan over the stove until it turns light red, then you are ready. You can make tons of this stuff this way, but I would recommend more research into the subject befor you go and make Ferro Thermite. Check out my post = Lota Questions (Related to Ferro Thermite) = in the general section, but they may move it here since i accidentally posted it there.

Quantum - 4-12-2003 at 04:44

Thanks for your help! Im not planning to make it just yet because I need more expereance first but I wanted to hear some advice. Andyboy's method involves putting small peices of Al foil in a blender along with water. The mesh is about 200 so it might work for thermite. Where can I find this Sulfur Dioxide and circuit etchant? I have Sulfur so perhaps I can oxide it somehow; if you know please tell me. I think heating it would work or would it just burn? The circuit etchant is more tricky. Can I buy it at Radio Shack?

Mumbles - 4-12-2003 at 14:17

Burning sulfur does in fact make SO<sub>2</sub> and some SO<sub>3</sub>.

As far as that Al powder method, it seems alright. I would think that the water on the Aluminum would form a fairly decent oxide layer. I think some other people use more inert mediums for this. Mineral oil sounds familiar. I use sorta the same method for pyro aluminum. I use that method with fairly large pieces, and filter out the remenants(about 20 mesh) and ball mill for a good week. I get a nice dark powder that works well. As I'm trying to clean the barrel of my mill out with water, I can hear fairly rapid fizzing. This gives me a fairly good idea that it is pretty fine. Perhaps my water is just pretty acidic or basic too.

As for the circut etchant, I haven't a clue where to get it. Might want to try a little more specialised store than radio shack. Radio Shack may be able to order it, but a more specialised store might have it in stock.

Tracer - 4-12-2003 at 19:12

You can get it at radio hack, but they may have to order the proper mixture.

O, and I fscked up, You want to use sodium hydroxide and pore that into the etchant. But dont get any on your skin! (Lye)

[Edited on 5-12-2003 by Tracer]

unionised - 5-12-2003 at 14:39

Just be warned that the reaction of NaOH and FeCl3 can be rather vigourous.
Mixing the solutions will give hydrated ferric oxide which you can roast to give Fe2O3

Quantum - 5-12-2003 at 18:28

Where can I get Ferric Chloride(FeCl3)? I know where to get NaOH OTC. Im defently holding back on this like my original post said. However I will make a few grams of Al powder and see how that burns. About using oil instead of water to cool the Al foil how would you get the oil out; could you use a solvent or will it evaperate?

Mumbles - 5-12-2003 at 21:40

You'd have to filter out the aluminum powder first. Then wash with a suitable solvent. Acetone should work well for removing the oil from the surface of particles. If it's too thick to filter, try adding some of the solvent to make more fluid. You could try adding water. Most of the aluminum should sink. Some will float on the oil, and between the oil and water layer. Just siphon off the oil and filter the Al out. Do it faster as the water will react with the Al. Thats just how I think it <i>could</i> be done. Thats the original discussion I took my ideas from. They have some working methods on there

cactus3178 - 9-12-2003 at 21:37

Mumbles - 10-12-2003 at 14:28

Are you positive that is Iron Chloride, and not something else?


Hermes_Trismegistus - 10-12-2003 at 23:56

Aluminum powder is available as Aluminum powder for metallic paints at an auto paint store....usually in a kit form with the associated paints and base coats but if you ask.......

I don't believe it to be oxidized badly because oxidation would reduce the sheen

Note* I've not tested this:(

unionised - 11-12-2003 at 03:57

That's what it says on the bottle.

Mumbles - 11-12-2003 at 05:32

Alright, I think I see where it might say ferric chloride but I can't tell. My monitor isn't the greatest.

Aluminum powder is also used in some fiberglass systems I believe. I've looked into this before, and buying from a pyro supplier is actually cheaper straight costwise than the suppliers I found. It wasn't an extremely hard search, but I found plenty of sources. The cheapest of what I have bookmarked is $17 a pound. This is on par with some pyrotechnic suppliers, but I doubt it's 600 mesh dark flake. I personally wouldn't use that(dark flake) on thermite anyway. I think something atomised, at a higher particle size would work just fine.

T_FLeX - 14-12-2003 at 16:44

A simple way to get a hold of iron oxide is to go to home depot and buy hydrochloric acid, sodium hydroxide, and steel wool.

Just dissolve the wool in the hydrochloric acid, but I have found it does take quit a while if you don't heat it. Once the iron completely dissolves pour in the sodium hydroxide, filter off the iron hydroxide precipitate and then burn it untill you get iron oxide.

You can make a good ammount of iron oxide with this method for relatively cheap. For zinc powder there is a guy on ebay that sells 10lb cans for around 25 bucks shipped. Good luck.

pyroscikim - 21-12-2003 at 19:31

"7.CO + 6.CH4 ==(AlCl3)==> C6H6 + C6H5-CH3 + 15/2.H2O " posted by Ramiel

This reaction looks feasible and relatively simple unless pressurising is involved which seems unnecessary.

Methane just comes off the gas tap at pretty high purity, and CO can be generated by heating a mix of excess conc sulphuric acid with oxalic acid (availiable in most hardwares), or anhydrous formic acid, or a metal-formate. With oxalic acid CO and CO2 are both formed in 1/1 ratios

(COOH)2 --> CO + CO2 + H2O

but shouldn't affect the production of benzene i believe.

The aluminium chloride can just be made from anhydrous HCl on aluminium, since this occurs at much lower temp than pure chlorine. HCl is generated by adding hydrochloric acid to concentrated sulphuric acid.

Put the AlCl3 into a ~2cm wide s/steel pipe and with some basic plumbing skills, one should be able to pass the CO and CH4 over the catalyst "bed" in the heated (to 300degC?) s/steel tube, and duct the vapours of benzene into a condenser or just a glass bottle in iced water...

the temperature of the catalyst could easily be adjusted and experimented with, and if this process works, you could get yourself a lifetime's supply of benzene if required... or just some fun with the practical work involved. The tube could also be used to contain other catalysts to make various chemicals like ethene and acetaldehyde...

seems pretty intriguing for the chemists who really want the practical process of synthesise and experimentation more than product

chemoleo - 21-12-2003 at 19:41

huh? Although it's an interesting contribution, you already posted this in the Benzene Synthesis thread....
Whats this got to do with Al and Fe2O3 for thermite?

Quantum - 21-12-2003 at 21:43

Thats err nice. I don't think Im ready to make benzene yet. Anyway thats OT.

theh0ser - 20-2-2004 at 18:27

can i get iron oxide by electrolysing water (salt solution) and running electricity through a piece of iron and a bolt and have the polarity so the bolt produces hydrogen and the piece of iron corrodes and then filter the water afterwards and dry out the stuff at the bottom? and also does putting water and Al foil in a blender give you thermite quality Al powder?

IgnorantlyIntelligent - 21-2-2004 at 10:30

I put steel wool in a bucket with water and alittle ammonium nitrate(helps rust it faster) After about a week there was nothin but orange rust on the bottom and some rusted steel wool still sittin above it. I extracted the powder at the bottom, dried it, and it was ready. It was probably coated slightly in AN which may have helped the thermite.
As for the AL, I dont think it matters. Any small flake or ball AL should work fine right? It just has to be small enough to form a kind of homogenous mixture like flash powder.
I never got around to use my iron oxide for thermite because I didn't get AL. Check paint stores.

Nevermore - 22-2-2004 at 11:02

Originally posted by theh0ser
can i get iron oxide by electrolysing water (salt solution) and running electricity through a piece of iron and a bolt and have the polarity so the bolt produces hydrogen and the piece of iron corrodes and then filter the water afterwards and dry out the stuff at the bottom?

that's definitely the best way in my opinion, i've been able to produce more than 50g of ferric oxide in 3 days by using an old iron driller point, a water jar and some salt, attached to a 12V recharger for auto batteries...
if you care to stick the iron to the + wire it will get corroded and form a very fine mesh ferric oxide at the bottom, the one i got was a thin dust, very alike the one that girl put in their faces..
i dried over an hot very hot plate till it became a nice dark red colour.
i've not been able to find AL powder yet..
still thinking about a way to produce..:mad:

theh0ser - 22-2-2004 at 11:49

the last time i tried to produce the iron oxide with electrolysing, the dried product was some iron oxide but mostly salt crystals...guess i didnt filter it good enough


axehandle - 24-2-2004 at 03:28

Why, oh why, do you insist of _making_ Fe2O3 when it can be bought at any ceramics supplier for about $1/kg ????

Mumbles - 24-2-2004 at 15:43

Simple, because you can. It is more fun to make things than to buy them. You get that nice sense of accomplishment for a job well done.

theh0ser - 26-2-2004 at 21:29

i made some thermite using aluminum from a beer can that i ground up with a file....does anyone know if this is pure enough Al or if it will work....i have a sparkler that im goin to light it with

axehandle - 27-2-2004 at 03:04

Beer cans normally have a protective plastic coating on the inside, and paint on the outside. Did you remove those? In that case I see no reason why it shouldn't work, unless the beer cans in question are made of some very exotic alloy, which I doubt. AFAIK, beer cans are made of pure aluminium, perhaps with a few % of Mg and/or Mn.


Simple, because you can. It is more fun to make things than to buy them. You get that nice sense of accomplishment for a job well done.

Point taken.