A better detonator?

[Polverone]

Manufacturing good detonators is one of the most hazardous and difficult tasks facing amateurs. Easy to make primary explosives, like lead picrate, acetone peroxide, and HMTD, are not very powerful. One may have to use several grams of these compounds to initiate an insensitive material (assuming the amateur in question doesn't have a sensitive HE in conjunction with the primary). The organic peroxides, especially, are a great hazard because of their incredible sensitivity to heat. They are powders, and packing them to high densities requires hazardous and nerve-wracking tamping or pressing.

There are a few high explosives that readily detonate from heat. Nitroglycerine is one such explosive; The Chemistry of Powder and Explosives describes drops of it violently exploding when they fall on a hot iron plate. So how about using an electrical heat source (nichrome wire or similar) to detonate nitroglycerine that has been absorbed in some porous medium? The absorbent, resistance wire, and casing could all be put together while the device was explosive-free and harmless. The nitroglycerine is added, the casing is sealed (this is the only part you'd have to do while the detonator was dangerous), and you just wait for the NG to diffuse through the media. The absorbent could be charcoal powder, diatomaceous earth, a cylinder of filter paper, etc.

Nitroglycerine is easy to make. It's very potent -- far more powerful than primary explosives. It's stable in storage, if cleaned of acid traces. It is still a fairly sensitive explosive, granted, but this is the case with all primary explosives as well. I also worry a bit about its viscosity. It might take a long time for the liquid to diffuse without manual mixing, which I would like to avoid.

I am sure that this is not a new idea, but I didn't find any mention of it here and I think it could be the basis for powerful, stable initiators that are safer to assemble. Is it practical? Are there problems I've overlooked? One thing that bothers me is that I don't recall Nobel or any of the other early nitroglycerine experimenters using this method, which makes me think that it may be harder to detonate from heat than a casual reading of COPAE would indicate.

[DaveTheShit]

I have always used a varying but small amount acetone peroxide as a detonator. If I was using it to detonate something insensitive I used a booster (usually picric acid). I really do not trust nitroglycerin - however easy it is to make - as much as I trust even AP. In fact, I haven't even made NG, though I did get some from a friend of mine. I would think that using AP and a booster would work as well or almost as well as using NG or NG with a booster. Plus with AP, you don't get headaches - to any of you who have made NG, how bad are those headaches?

[Anthony]

DavidThePyro, NG really isn't so bad. At least it found (and still does) industrial/military use, whereas peroxides were deemed to unstable.

I can't remember who, but one member of this forum reported good results with NG soaked into cotton wool, in a .22 shell and initiated with a stun gun sparked across the end of coax cable crimped into the shell.

I'd imagine that if it was sensitive to the weak spark of a stungun, it should be sensitive to a burning filament.

I wouldn't worry about adding the NG just before use. Well made NG would make for storage stable caps - a desirable thing that peroxides cannot guarantee.

Naturally, I'd leave the NG to stand for 2-4weeks to allow any slow discolouration to show, before adding it to the caps.

[nbk2000]

Unfortunately, any liquid mixed with a solid is going to seperate out over time, because what you've described is basically a tiny stick of dynamite.

Once seperated, the NG would likely no longer function, or would do so erraticly. So these wouldn't be storable for long lengths of time, but they'd be good to whip up just before use if you had the NG dissolved in acetone for safety and evaporated it just prior to loading.

[Microtek]

I generally find that liquid explosives are too inconvenient to work with; it's difficult to eleminate airbubbles from a closed container, and the container needs to have a tighter seal ( I made some tests with NG detcord but problems such as these made me drop the idea and go for extruded polymerbonded PETN instead ).
There is also the problem of LVD with NG which would probably be quite acute when initiated in this manner.
I recommend that you try nitromannitol instead, or hexanitro inositol which there is a patent about. In this patent, HNI is initiated by an electric match or by a match composition placed where you would normally place the primary and ignited by fuse. They use 0.16 - 0.5 grams of HNI, so the caps don't need to be any larger than usual.
Inositol is another name for cyclohexanehexol and shouldn't be too hard to get ( same as mannitol I'd expect ). It is also called i-inositol or myo-inositol with the biochemical crowd.

[Mr Cool]

"Inositol is another name for cyclohexanehexol"

Sounds like mannitol's cyclic cousin. Might be available as a sweetener, although I never came accross it when I was looking for a mannitol source. The only useful ones I came accross were mannitol, erythritol and xylitol.

I still think the best method is the EBW cap (although I prefer fuse ignition over electric for some unknown reason), a suitable circuit can be put together from a few disposable cameras and you'd never need a primary again. Such a circuit, in conjunction with a bridgewire system I developed, will detonate MHN, NG, EGDN and PETN easily, even with 10% of an inert substance such as blu-tack binder. I'll draw some diagrams of the bridgewire, it's convenient to use and more sturdy than a bit of steel wool soldered between two wires. Unfortunately I can't give you photographs because the camera isn't here with me. Another good and strong bridgewire can be made from circuit proto-board, the circuit board you can buy from Maplin's etc that has lots of long, parrallel copper strips with lines of holes drilled down them, you just cut off a section two holes in length, solder a wire in each, and the copper tracks in between get vapourised, although this didn't work with the camera circuit. I suspect the discharge is too slow. It did work very well with 0.2uF @ 5kV though.

I think NG might suffer a LVD when ignited by the hot wire method, especially if the heating is too slow. A liquid nitrate ester/solid nitrate ester paste could be good though.

Edit: here's a brief description of the bridgewire. It's a rough 5 minute drawing in Paint, so please excuse the nasty artwork, but it should get the idea accross...

<a href="http://www.boomspeed.com/mrcool/EBW.jpg" target="_blank">EBW</a>

<small>[ February 05, 2003, 02:42 PM: Message edited by: Mr Cool ]</small>

[nbk2000]

Inositol is sold in some health food stores as an alternative to sugar. It's also a good cut for "peruvian marching powder". <img border="0" title="" alt="[Wink]" src="wink.gif" /> :D

If you used a nichrome wire to heat the NG, it'd have to be done fast enough that the wire reaches the needed heat to cause the high level detonation, otherwise the NG will flashboil without exploding, or will do so at very low power.

I could see an EBW having a small crystal of frozen nitro placed on the tip then being dipped in some sort of sealant. The NG would then melt, forming a tiny pocket of liquid NG on the EBW, that would act as the detonator to set off the NG, which would set off (whatever) in turn. :)

[Microtek]

Mr Cool: I have been using almost the exact same setup as an exploding foil initiator. I just position the narrow section of foil on the face of the cardboard instead of on the edge ( simply by glueing the foil onto one side of the cardboard and then cutting a wedge from each side of the strip to leave a narrow section ).
I use these for my caseless detonators because it then is possible to make very short caps ( less than 10 mm ) that will initiate plastique when placed on the surface of it rather than in a well.

[Da Boom Doctor]

I've also been trying to improve my Cap manufacture by expirementing with some new designs, and during a daydream in a physics lesson a couple of days ago I was considering if it was possible to cause the detonation of AP by passing a current through it (in the form of a capasitor bank discharge) however from previous expirmentation I understand that AP does not conduct electricity and will not detonate by an atempted capasitor discharge across it (the capasitor does not actualy discharge as AP seems to be an insulator) - I am not sure whether I am correct here, so please tell me if you have had different results. However with my understanding, I thought that discharge may be achieved by adding a conductive powder (eg graphite) to the Ap, hopefully causing detonation.
Do you think this would work?
Thanks :)

[Mr Cool]

That's what I tried first, Microtek, but I found cutting it to leave the small bridge a bit too tedious, it kept on ripping. My method requires no careful work, although I can see that the method you use would be more convenient for some applications.
I use mine for really small tests, when any sort of detonator would be impractical. They're great with MHN/blu-tack binder plastiques/PBX's. They also work well with MHN or PETN in caps, you just press the base, then push these upright on top, and seal it in place with molten wax.

[Anthony]

Just use a high enough voltage to arc between two electrodes, rather than relying on the medium between them to be conductive.

A cap bank isn't needed for AP, the discharge from stungun is sufficient.

The point of an EWB is to remove the need for sensitive and possibly dangerous primaries.

[IPN]

Does anyone now how this hexanitro inositol is prepared.
I didn´t find any patents for it.
I searched from <a href="http://ep.espacenet.com/espacenet/ep/en/e_net.htm" target="_blank">here</a> and
<a href="http://www.uspto.gov/patft/index.html" target="_blank">here</a>

Or would the preparation be similar to mannitol hexanitrate?
Using inositol instead of mannitol.

[Microtek]

I'm fairly certain you could nitrate inositol as you would mannitol, adjusting for slightly different mol-weight.

[andreas]

Fructose is quite similar to inositol.
missing one OH-group and having the other OH- group on a methelene group.
Fructose pentanitrate might be a usefull explosive if it cristalises and doesn't form more liquid kind of explosives.
And if it isn't prone to oxidation.
I might try it when I get some H2SO4 somewhere this week.
Or has somebody tried it before??

[Mr Cool]

Doesn't fructose have a C-O-C bond in the ring, and exists in equilibrium with a straight chain ketone form? This could make it behave quite differently to inositol. I'm sure its nitrate would be a powerful, sensitive explosive, but you will get more oxidation during nitration and it might have a rather unstable product, as with nitrating other sugars such as sucrose.

I found a few inositol sources, but all are very expensive. Like a few $/ounce.

[andreas]

You're right Mr Cool. I'm wasn't looking very carefull.
Today I bought a litre of H2SO4 so I will be doing a test of a few grams later tonight.
I'll post the results here.
Hope it gives a cristaline nitrate.

[IPN]

I’m not sure but I believe that nitrofructose would be syrup like explosive substance.
Because fructose (or levulose) is an isomer of dextrose with the formula C6H12O6
And according to COPAE nitroglucose is colorless viscous syrup.
Comes hard at 0 degrees celsius.

And Mr Cool I could order 1kg of inositol for about 150$!
That is way too much for 1kg!

[andreas]

Whell I tried it tonight, and it is a chewinggum like substance in warm water but is hard a room temp.
It burns quite slow but I think there is still some moisture left in it. Tomorrow I'll make a small detonator with it. And compare it to MHN

[IPN]

I just checked from COPAE:

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica"> Fructosan trinitrate is produced by the action of mixed acid at 0-15C on d-fructose, colorless, quickly effluorescing needles from alcohol, which melt at 139-140C and decompose at about 145C. </font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">