Thermite Help!

[Atra]

I know this must have been asked a million times but thats why I'm in the water cooler. Ok I've tried everything. Fe2O3 made by electrolysis, vinegar-bleach even Fe3O4 made from super fine steel wool. I know its not my aluminum because that makes amazing flash powder 20g's of which left a good sized hole in a boogie board placed in a pool. But thats not the point the mixture is of the right ratios and is heated with a butane torch and mangesium place on it then lit it gets to the point where its white hot and melts but still doesn't ignite. What am I doing wrong?

[Jacks Complete]

Well, yes, this is odd. I assume you are mixing it about 50/50 and throughly?

If your aluminium is ok, and your rust really is rust, and both are air-float, then it should work. It's about as simply as anything. It doesn't go off without extreme temperature, it doesn't degrade over time, it's waterproof, shock inert, etc.

Just light the magnesium ribbon and drop it on, don't heat the whole mix, btw.

[Sausagemit]

If you have any KMnO4 and glycerin lying around you could try a 10/4/3 ratio of iron oxide (Fe203), KMnO4, and Al respectively. Do not mix the KMnO4 in with the thermite though. Simply make a depression in the thermite and gently poor the KMnO4 in the depression. Then when you’re ready to ignite it, poor some glycerin on the KMnO4 and stand back. And if it still doesn't ignite I really don't know what to tell you.

Or if you want to give up on thermite, go to your local arts and crafts store and pick up some plaster of paris (CaSO4). Mix it 6/4-CaSO4/AL by weight respectively. And this mixture is castable. Simply add some water, poor it into a mold, then bake it for quite a while at 200-250 deg F. While not as hot as thermite, it is much brighter and can be ignited with a propane torch just as long as you’re careful (ie, heat from the side and never from above) and wear some welder’s goggles so as not to damage your eyeballs.

I have also heard of mixing MgSO4 in with this mix but I have not tried it yet as I have not been able to find a working ratio on the net. And you would have to bake it at a higher temp because MgSO4 is highly hygroscopic and to bake out the water it would have to bake at around 450 deg F.

[Atra]

Thank you. Actually the Potassium Permanganate was my next idea I just ordered some. I'd rather not simply give up on thermite because it seems to have become the bane of my existance as the flash powder and smoke bombs and AP all worked very well but something as simple as thermite evades my limited expertise. The only thing I can think of is that the magnesium I've been using is large pieces not strips we pile them up and it does get white hot but that could be it. I'll see if the Permanganate works. And does anyone know if the potassium nitrate sucrose reaction gets hot enough to light thermite because that does melt aluminum I learned that the hard way.

[Jack2k2]

Another idea would to be igniting the mixture with a High Amperage arc.

Usually the Magnesium should work, so it may well be that your Iron Oxide is not correct. Anyways, a High Amperage arc can be easily obtained from a Microwave oven transformer(MOT). They usually can run off 120v 15a, and output 2kv at 500-1000mA. Unfortunately since they are low voltage, the 2 outputs must be within a small distance (matter of a few millimeters) to arc across the gap. However this tiny arc will be extremely hot and bright. So if you could bring a MOT out to where you are doing the thermite and stick the outputs into the pile of thermite, it should ignite, just use long thick gauged wire going from the mots to the pile of thermite to make sure the thermite doesn't destroy the mots as well.

Also, careful with the MOT's are quite lethal. (30mA is usually enough to fibrilate a heart, 500mA can do quite a lot more.)

[Jacks Complete]

Hmm. It's incredibly unlikely that the rust is bad!

the magnesium I've been using is large pieces not strips we pile them up and it does get white hotThis is probably where the issue lies. Is your magnesium burning brightly white and under it's own power? It should be a very bright white light, blindingly intense, and self-supporting once lit. If it doesn't, your magnesium is probably aluminium!

[nbk2000]

Firework sparklers never fail to light it, if buried well into it. :)

[Atra]

No, the magnesium is plenty bright. We put a bunch of pieces on, and it gets really hard to look at, and you have to stand back. Like I said, it gets hot enough to get the mixture white hot and melt the aluminum and iron oxide into a solid thing. Although I do like Jack2k2's idea purely because it sounds cool, but I know my rust is right because what else could it be with steel wool in bleach and vinegar and aluminum works good enough for flash so should be fine for thermite. Also, the magnesium is definately not aluminum. You can't burn large pieces of aluminum very easily and they're not white hot. However, I was wondering if sausage meats idea for the aluminum and plaster of paris idea would be hot enough to light thermite.

[Alexires]

Jacks Complete - I've actually found that magnesium ribbon will only burn for 10 or so centimetres (about 4 inches) before it goes out. If you are using magnesium ribbon, I'd suggest crumbling it into flakes, then lighting that on top of the thermite, which would hopefully give a higher temperature and more reliability.

Sparklers ARE really good for lighting things. Break the powder off the sparklers and that burns pretty hot (and fast).

[Randel]

How nice it is to find an answer to stupid blur on tv. Mythbusters just did thing with thermite and set it off by using two chemicals they blurred out. One was a clear oily liquid the other you dont see. I'm guessing it was Sausagemit KMnO4 and then glycerine as the oily liquid. Anyway now that I know what it was I can go give it a try. Thx for the answer before the question.

++++++++

The permanganate needs aluminum powder added to it for it to ignite thermite. NBK

[Lewis]

Got a little question for someone who's done this before:

Seems that electrolysing a brine solution with iron electrodes is a common way of producing rust quickly for its use in thermite. My question is will this produce any really harmful fumes?

I'm also interested in a chlorate cell, so seeing as the only place I'd have to perform electrolysis would be my house, is it smart?

[Jacks Complete]

Re-reading this, it occurs to me that if the OP was using a large amount of bleach he would create Iron Chloride, rather than Iron Oxide, and I have no idea if that would work in Thermite. Get your wire wool, put in it aerated water and add a small pinch of salt to speed this corrosion.

Lewis, no, you will get hydrogen though, which is explosive at even low concentrations, and you may find that to be really harmful. Or you can fill balloons with it, tie with a string, light said string and let it go outside to float away then burn up.

[Lewis]

I've heard the reaction also produces elemental chlorine gas, which is heavier than air. Surely this isn't something I want building up in my basment!

[nbk2000]

This thread is drifting into k3wL'ness, so I'm shutting it down.