Thermite - split from magnesium welding thread

roofman · Jan 22, 2012

KemppiFrog said:
Mag was used for VW gearboxes a while back. Friend managed to use his as an earth while welding the structure of his auto-cross racer. Had the presance of mind to chuck sand over it in time. (Turbo Volvo powered, class winner)
KF

Mag dust and iron filings make Thermite. Favoured material in incendiary bombs. Will burn through almost anything.

is that the process they use for welding railway lines?

tigler · Jan 22, 2012

Certainly is ! Would love a go at that !

roofman · Jan 22, 2012

tigler said:
Certainly is ! Would love a go at that !

me too...once the chemical process starts it seems to be totally un-controllable untill it finnishes though

tigler · Jan 22, 2012

Yup, will melt through anything ! Another fun toy would be a thermic lance !

hotrodder · Jan 22, 2012

Thermite is most commonly aluminium powder and iron oxide although there's various flavours. I'm pretty sure they showed us that one in school although it might have been some other redox reaction. Either way the teacher was a bit of a nutter and it didn't take much encouragement for him to overdo it a bit- instead of pouring the two ingredients into the little reaction beaker he buried the beaker under a pile of the stuff, stuck a bit of mag ribbon it for a fuse and lit it. Shortly afterwoods we had to evacuate the building due to the smoke. I think the biggest miracle was that he kept his job :laughing:

Thermite video recipe... http://sim71.hubpages.com/hub/The-Thermite-Reaction A thermic lance is almost as easy to make as thermite, here's one made out of spaghetti and kitchen foil... http://www.youtube.com/watch?v=mKZtb6dTWSY

Robotstar5 · Jan 22, 2012

roofman said:
is that the process they use for welding railway lines?

A friend of mine was involved with rail welding. A form is put round the prepared ends of the rail and a pot with the thermite mounted above it, the thermite is lit and the molten contents pour into the form welding the rail ends together. Any excess is collected in a catchpot below, if they are near a bridge over water (stream, river, etc.) the catchpot is thrown in to create an impressive bang apparently, although as most work is carried out in the wee small hours the sleeping locals don't seem to find it so funny :laughing:

brightspark · Jan 22, 2012

Robotstar5 said:
A friend of mine was involved with rail welding. A form is put round the prepared ends of the rail and a pot with the thermite mounted above it, the thermite is lit and the molten contents pour into the form welding the rail ends together. Any excess is collected in a catchpot below, if they are near a bridge over water (stream, river, etc.) the catchpot is thrown in to create an impressive bang apparently, although as most work is carried out in the wee small hours the sleeping locals don't seem to find it so funny

well they shouldnt live near a railway then :rolleyes:

i live in a railway house right on the rail crossing . u get used to it

TechnicAl · Jan 23, 2012

I once did some hardfacing using thermite. Got the powder added some chromium carbide and built a dam around the plate. Got it hot and then started the resction using Mg ribbon.

It was awful, we expected it to be self levelling...it wasnt. The plate distorted in every direction and the weld surface resembled the moon

Oh well you have to try these things

The powder used to come from MUREX METALS but I havent heard of them for years

rtbcomp · Jan 23, 2012

I think they burnt down.

Shox Dr · Jan 23, 2012

TechnicAl said:
I once did some hardfacing using thermite. Got the powder added some chromium carbide and built a dam around the plate. Got it hot and then started the resction using Mg ribbon.

It was awful, we expected it to be self levelling...it wasnt. The plate distorted in every direction and the weld surface resembled the moon

Oh well you have to try these things

The powder used to come from MUREX METALS but I havent heard of them for years

Every idea is the best, until Hindsight pokes her noise in :laughing:

KemppiFrog · Jan 26, 2012

A teacher at an international school near my late residence used to mix up thermite 'bombs' for his science lessons. Then dug them up from the depths they had melted down to, to show them the results. Doubt this is OK in the current PC culture.
KF

Pete. · Jan 26, 2012

I watched some rail welding with thermite - was hoping for something spectacular but it was a total anti-climax. Much more impressive when they do it on Brainiac

pedrobedro · Jan 27, 2012

We had a furnace shut down mid melt at a foundry I worked in years ago and we used a thermic lance to cut the solidified metal (skull) out. You needed an oxy-propane torch to light it and had all on seeing what was happening but it cut through everything in front of it. It was so long ago I don't remember much about it but it was like a conduit with iron filings in it and an oxygen feed. It was noisy and dirty, a bit like Dante's vision of hell I would imagine.

sean-1 · Jan 27, 2012

We used to make our own thermal lances when i used to work in a foundry. Realy simple 1 1/2 stell tube packed with welding rods and wire wool and and oxygen bottle connected to the top, once lit we used to chop up old fork lift and excavator counterbance weights so we could fit them in the melting pots.

Robotstar5 · Jan 27, 2012

pedrobedro said:
We had a furnace shut down mid melt at a foundry I worked in years ago and we used a thermic lance to cut the solidified metal (skull) out.

We used to "drop the bottom" of our furnace each day, the fused sand lining would normally break and fall. If it didn't, a casting or two dropped in the top usually did the trick, if that failed the thermic lance was used :laughing:

TechnicAl · Jan 27, 2012

sean-1 said:
We used to make our own thermal lances when i used to work in a foundry. Realy simple 1 1/2 stell tube packed with welding rods and wire wool and and oxygen bottle connected to the top, once lit we used to chop up old fork lift and excavator counterbance weights so we could fit them in the melting pots.

Thats basically how we used to make them. Did you know that you need a license to make them and you have to keep very details records of who you have sold them to.
We used to make them about 10 feet long, 4mm wires inside and threaded one end for the Oxygen to connect to. Get them going with oxy propane.

Just as a "trial" we burned through a 28" thick wall made of blocks and cement, in absolutely no time at all.

chunkolini · Jan 27, 2012

The chattering classes use spaghetti.
http://www.youtube.com/watch?v=mKZtb6dTWSY
I have been tempted to have a go at making one of these for years, but cant think of any reason to, and dont fancy blowing myself up.

Punx0r · Jan 27, 2012

Add ice to the thermite reaction

http://www.youtube.com/watch?v=IuPjlYxUWc8

KemppiFrog · Jan 27, 2012

Bit puzzled by the vid. Pretty weak wristed if it took so long to cut a hole in a garden chair. The torch alone could have done that. Obviously they were having fun (and what on?) If you really want some fun, try flour bombs or filling a dustbin with gas and igniting it. Tutorial to follow, if anybody is interested.....
KF

Certainally not a 'How To' for crims planning a bank job :laughing:

rtbcomp · Jan 27, 2012

KemppiFrog said:
........
Certainally not a 'How To' for crims planning a bank job

Just as well, someone has just been given 2-1/2 years for downloading plans about making bombs "out of curiosity".

Thermite - split from magnesium welding thread

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