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Experience with copper thrermite


#1

greetings from Alaska,

anyone have experience with small scale copper thermite?

thanks,
Jim


#2

Hi Jim,

Non-ferrous thermite reactions appear to be really dangerous, well
more dangerous than ferrous reactions, and really any thermite
reaction is dangerous.

Basically a thermite reaction is an oxide, plus fuel, plus an
ignition source. The proportions of oxide to fuel will result in a
better burn, so to speak.

Funny thing about thermite reactions… everyone finds them
entertaining :wink:

I can send you links to people that experiment with these reactions
if you like. They’ve done the experiments, you can see the results
without having to put yourself at risk :wink:

Regards Charles A.


#3
Non-ferrous thermite reactions appear to be really dangerous, well
more dangerous than ferrous reactions, and really any thermite
reaction is dangerous. 

I gather that Charles has used thermite before - I haven’t. We have
an electric commuter train here (BART) that runs at 80mph in the
straights. That means the rails are seamless, like one long rail.
There’s no “clackety clackety clack”. That is done with thermite -
they put a new piece of rail in place, put a thermite pack on it and
it fuses the ends together like one piece. Then they have special
machines to profile it and smooth it.

Any thermite reaction is essentially a controlled explosion, and
they generate tremendous heat and energy. Most importantly, once
started there’s no stopping it. Tread carefully there…


#4

As a youth I always found thermite a lot of fun in that it was cheap
and easy to make (iron oxide and aluminum powder) and generated lots
of smoke and “fireworks”. A common way to use it was to place the
mix in a steel funnel with a piece of magnesium ribbon running
through the center. Light the ribbon and clear out. Sparks of molten
steel fly all around and a stream of molten steel pours from the
bottom of the funnel. That is how welding was accomplished. In the
original of the sci fi movie, “The Thing”, the creature’s flying
saucer was freed from the artic ice by use of thermite, but caught
fire and was destroyed. That started my interest.

Gerald Vaughan


#5

Hi John,

Quite correct John, I’m using it in experimental casting processes.

The thermite process was originally developed as a welding process,
however it is often only thought about for its destructive ability.

If you are to “ever” experiment with these reactions, do them with
the minimum amount of material required for the purpose. You must
research before you ever set one off, and you must have sand on hand
to quench a reaction if it ever gets out of control. I also advise
that you have a safe area for the reaction… I have a small brick
bunker built specifically for the serious reactions.

Last word of caution “Thermite will burn to dirt”, this means
whatever it’s on, it will burn through, until it gets to the ground.

Regards Charles A.


#6

Hi Charles,

Quite correct John, I'm using it in experimental casting
processes. 

Are there any pictures where you use thermite in a casting process?

Enquiring minds want to know and see…

Cheers, Hans


#7

Hi Hans,

Are there any pictures where you use thermite in a casting
process? Enquiring minds want to know and see.... 

Thus far, it’s been a matter of experimenting with the viability of
mixtures. Proof of concept more than anything.

Sourcing and testing local resources. Ratios of oxide to fuel.
Testing the equipment.

For example a good source of iron oxide is the local hardware store,
cement pigments, they work very well, and colour seems to be a
factor (what that factor actually is, is still under investigation).

Here are some minor reactions :-

Black Iron Oxide http://www.youtube.com/watch?v=otCyRfWbFGY

As expected, no problem with the reaction.

Red Iron Oxide http://www.youtube.com/watch?v=I5-VhwBQo84

The powder was a little compressed, so ignition was unable to be
maintained. A bit of agitation and the mixture completed combustion.
The compression was due to the nature of the oxide.

Yellow Iron Oxide http://www.youtube.com/watch?v=uEEPPLMecgA Same as
red.

The next step is to take the equipment to the next, and implementing
it into a gravity casting system. The important consideration is to
have enough material to have a molten flow, and a delivery system so
that casting can take place.

This process works with any metal oxide, it’s just about getting the
ratios correct, and in the case of titanium, you need to add a few
other ingredients.

Can you make alloys this way, yep, and there are a few people
attempting to make steel this way.

Regards Charles A.


#8
This process works with any metal oxide, it's just about getting
the ratios correct, and in the case of titanium, you need to add a
few other ingredients. 

So one could cast titanium with this process? I would love to know
how I could cast titanium with a gravity process using thermite. Any
pictures?

Cheers, Hans


#9

Hi Hans

I thought I’d chirp in on this one, I’ve been playing with thermite
formulations for a few years and I thought you should know that
copper thermite using cupric oxide is actually quite explosive check
you tube, albeit the raining calamity is quite beautiful.

But now that it’s mentioned, how’s the titanium preparation made?


#10

Here you go Hans,

Here’s a site that’s on the way to casting Ti.
http://tinyurl.com/yn5u5k

If you can get molten blobs, the next step is to figure out a way to
cast it.

Regards Charles A.


#11
Here's a site that's on the way to casting Ti.
http://tinyurl.com/yn5u5k If you can get molten blobs, the next
step is to figure out a way to cast it.

It will be highly unsatisfactory as a casting method for Ti. If you
look at the EDAX scans he shows on that site the Ti is so horribly
contaminated with aluminum and carbon it will have all the ductility
of glass. And that scan is not showing how much oxygen and nitrogen
that Ti has absorbed from being molten in air. There is just no way
to cast Ti in air that will yield a ductile material. It also will
not develop the oxide colors you normally want to get with Ti due to
the high oxygen content.

James Binnion
James Binnion Metal Arts


#12
Here's a site that's on the way to casting Ti.
http://tinyurl.com/yn5u5k If you can get molten blobs, the next
step is to figure out a way to cast it. 

It will be highly unsatisfactory as a casting method for Ti. If you
look at the EDAX scans he shows on that site the Ti is so horribly
contaminated with aluminum and carbon it will have all the ductility
of glass. And that scan is not showing how much oxygen and nitrogen
that Ti has absorbed from being molten in air. There is just no way
to cast Ti in air that will yield a ductile material. It also will
not develop the oxide colors you normally want to get with Ti due to
the high oxygen content.

James Binnion
James Binnion Metal Arts


#13

Hi Gaston,

But now that it's mentioned, how's the titanium preparation made? 

Always happy for people to chirp in with safety warnings, as dealing
with this medium is inherently dangerous.

Copper thermite, if not treated with respect, can provide a blast
wave, and numerous grass fires, here is a testimony :-

http://amazingrust.com/Experiments/how_to/Thermite_pics-videos.html

Video #2 of the Copper Oxide reaction outlines the potential
dangers, and #3 isn’t much better.

I have no intention of ever doing a copper thermite reaction…
ever.

The Titanium mixture, or a start without giving you the exact
formula :-

http://www.amazingrust.com/Experiments/how_to/Thermite.html#TiO2

Regards Charles A.


#14
It will be highly unsatisfactory as a casting method for Ti. 

I realize that much of this thread is a fascination with fire and
explosions, which I share to some degree. On a practical level,
think about the problems - you have an uncontrolled, intensely hot
melt, whether copper or titanium, and molten metal is just plopping
out the bottom of it without any real control over the
alloy/gas/impurity mix. I can’t imagine any way of casting that way
with vacuum or centrifuge, so you would be limited to gravity
casting, and your whole rig will have to withstand the heat and
pressure (it’s a controlled explosion) Sure, fine, why not?

I don’t remember the name, now, but I talked to some folks in Florida
who will cast anything you like in titanium or stainless steel.
Induction, inert gas, all that stuff and you get a real product.
Pretty cheap, too as I remember. The real way thermite is generally
used in industry is a welding operation. Instead of getting a huge
torch and taking 2 hours to weld train tracks together, just put a
thermite pack on it and fuse those suckers together in 2 minutes…


#15

Hi John,

It’s just mad science really, but there’s enough interest in a
possible thermite casting procedure that I’m spending the time to
explore the possibilities.

For non-ferrous metals you don’t need to melt it with a thermite
reaction, a good torch and $20 worth of refractory, you can melt
non-ferrous pretty easily, and safely.

Ferrous metals require a lot higher temperatures, and a thermite
reaction provides enough heat to do the job. If you are interested
in “playing” with iron, then this is an option.

Gravity is what I’m concentrating on, and have a setup ready for
testing. The delivery is enclosed, and the theory is that the molten
metal will flow into a cavity and fill it. The testing comes next.

I have considered vacuum, and it could work, although my aim is to
make the process available with minimal outlay.

Regards Charles A.


#16

I’ve been reading the comments about copper thermite. I’d heard of
iron based thermite. Here is a video showing the difference. Really
funny. http://tinyurl.com/26mwy5z

I started learning about it after seeing it on Mythbusters, they love
the stuff.

Rick


#17
I started learning about it after seeing it on Mythbusters, they
love the stuff. 

They must have gotten the mix wrong, or there could have been an air
pocket or some water in there.

I did mention that copper thermite is a bad idea even if you know
what you’re doing.

Regards Charles A.


#18

I sent the same video link to a buddy of mine in the military. His
response was that copper thermite has been used in military
explosives since WWII specifically in anti-tank weaponry. The German
military had an RPG called a Panzerfaust which was an anti tank
weapon. His point was with that much, the kid was lucky he did not
have it either in a contained form or packed because it could have
been deadly. Just wanted to pass the warning along. The aluminum
thermite is what Mythbusters uses which burns but does not explode.

Rick


#19

Hi Rick,

And sage advice it is too. I was thinking that these kids were
"very" lucky indeed.

A slight correction here, all thermite contains aluminium, it’s the
base of thermite.

Regards Charles A.


#20

Hi all,

Err…not to be hopelessly pedantic, but the panserfaust’s warhead
was shaped charge composed of TNT cut with RDX. (50/50 IIRC) Nothing
to do with a copper thermite.

Not to diminish the dangers of copper thermites. They’re nothing to
screw with.

Regards,
Brian.