52 replies to this topic

[Nitrate lightning]

Hi guys

Has anyone had any success with copper oxide + aluminium thermite? And what weight percentages do you use?

Thanks.

[paul]

A stoichimetric mix works well, but thermite has hardly NO use in pyrotechnics.

It does not give off any gases (not really). It produces a few nice sparks and a cloud of copper if you use al finer than 50? but....

Let?s wait for the others to answer :)

[Nitrate lightning]

Ok I saw a video of it on Stuarts website. Looks fantastic! Sadly his site has server problems at the moment.

[KingVinny]

Using the formula:
3CuO + 2Al ----> Al2O3 + 3Cu
The ratio of CuO to Al (by wieght) is 4.4 : 1
Different to the ratio on Stuart's site but produces a more impressive reaction. Takes a fair bit of heat to start it off however. Magnesium ribbon is the best thing to use. Failing that you can use CuO + Zn thermite (1:1) on top of the CuO + Al, with a 7:3 chlorate sugar mix on top of that as you can then set it off with a fuse.

[Nitrate lightning]

Ok thank you very much I will test it this afternoon if my Al powder arrives.

[Nitrate lightning]

I tried 4.4 copper 1 Aluminium today. It burnt very slowly and left residue! My Al is very fine and pure and same with my copper oxide. How fast does it normally burn? What procedure do you use to make it?

Sorry for asking so many dumb questions its just that I have loads of copper oxide and I dont want it to go to waste.

[KingVinny]

I use bronzing aluminium and copper oxide from a pottery supply company and once lit using CuO + Zn thermite and a chlorate sugar mix it burns extremely quickly. When loosely confined it creates a big flash with large sparks and a brown copper vapour cloud. When confined in something like a film canistor it tends to explode upwards and looks similar to a star mine going off. Residue that gets left will be copper metal and aluminium oxide.

How did you ignite it? To get it to burn fast it has to get very hot very quickly all over. If I put it in a film canistor I fill it 1/2 - 2/3 full with the thermite then make a hollow in it and pour some CuO + Zn thermite in until it is completely covered. Then put a 1/2 cm layer of chlorate sugar mix on top of that, put a lid on and stick a fuse in through a hole in the lid. Creates a very nice affect.

If you give me your email address and if you have an up to date version of quick time player I'll send you a couple of video clips of my thermite going off. It is fairly bad quality though as it was filmed on my phone but you get the idea.

[Nitrate lightning]

Ok my email address is in my profile.

I am amazed by this stuff! Check out this video one matchbox full! Not bad! LINK
(not my video!)

Tommorow I will have a go again and ill use a small french banger to let it off instead of Mg ribbon which is a waste of time. according to this link I found -sparks can let it off?

LINK

I may also try S and Al to let it off.

Edited by Nitrate lightning, 05 October 2004 - 08:07 PM.

[KingVinny]

I would say the best thing to set it off is a hot burning composition. I don't think a banger would work but you may always prove me wrong, as in the link you gave people were using HMTD to ingite it. The video at the top of the list was very impressive but then it was set off with a high explosive. My thermite does create a similar brown vapour cloud and sparks however.

Message me with your email address, as using the link to it on your profile, I can't see a way to send video clips.

[Demented Ferret]

Hey, Just like to tell you that any good BP will set off a decent Iron Oxide thermite composition. While I haven't tested Copper Oxide thermite with BP, I'm quite certain that a burning Iron Oxide thermite will create enough energy to activate a Copper Oxide thermite.

[Creepin_pyro]

any good BP will set off a decent Iron Oxide thermite composition.

Are you sure about that? I thought you needed a very high temperature to light Thermite, hence the Mg ribbon.

[paul]

That answer is certainly not right. It depends on the particle size. For thermite mixtures you normally use a coarse aluninium! And if you do so it is NOT possible to ignite it with black powder.

Fine copper oxide and german dark Al ignites easily with a fuse (no first fire needed).

With 50? Al particle size it is possible but not given that it will ignite from a fuse. A bp first fire will "fix" this problem.

And finally CuO2 + coarse Al. This mix NEEDS a first fire mix. Al/S 1/1 will set it off. Other compositions like Kno3/mg work fine, too.

But Al/S 1/1 is the best mixture to ignite thermite... 4g of Al/S burt through a 0.5mm thick metal sheet..... The mix itself ignites easily. If it does not, mix in a few % bp.
Al/S itself is a very very powerfull "thermite" mixture itself, but works only with Al < 70? for me.

I tested all the Al types as stated above in stoichiometric compositions with CuO and CuO2, so I hope this helps.

Edited by paul, 08 October 2004 - 01:18 PM.

[RegimentalPyro]

Handy Tip!

You can use a sparkler to ignite most thermites. They certainly burn hot enough so no "first fire" is required.

[Nitrate lightning]

Exellent Ill buy some today

[Demented Ferret]

My BP sucks real hard but manages to set off even random-ratioed Thermite (within reason, not 99:1 or anything ). I'm 10000% certain and would be willing to FILM evidence of it if you don't believe me. The 'Thermite is invincible and needs extreme activation energy' is just a myth, trust me from one man to another on this.

Edited by Demented Ferret, 09 October 2004 - 10:20 PM.