Sciencemadness Discussion Board

Detonation of erythritol tetranitrate (ETN) with heated aluminum

 Pages:  1  

Melgar - 13-3-2010 at 01:41

I'm not sure if this is normal, but ETN seems to have a special reaction with aluminum, in that it detonates when in contact with it and heated to boiling. I tried heating tiny pieces of ETN on various materials steel, aluminum, and glass) and the stuff actually detonated when in contact with aluminum, though not the other two. So far this has been a very reliable way to detonate it, although the timing would not be nearly as accurate as with a blasting cap. ETN can even be detonated by wrapping it in aluminum foil and putting a chunk of black powder underneath it to provide the heat. This would also explain why reports have indicated ETN can be detonated with flash powder, since flash powder tends to have a lot of aluminum in it. Of course, flash powder isn't all that stable, but I'm willing to bet thermite would detonate it, especially if a little extra aluminum was used. Anyone have any experience with this?

User - 13-3-2010 at 02:25

Quite interesting.
Did you notice any different behaviour between rapid heating e.g. with BP, or by slow heating on a burner or hotplate?

Melgar - 13-3-2010 at 04:20

Ah right. Yes, when heating ETN with aluminum, there was a rapid bubbling and a change in color (to orange) immediately preceding the detonation. I'm quite certain this orange color was from nitrogen oxides, although I did not repeat the experiment due to the extremely loud noise generated by said detonation coupled with the fact that I have neighbors. It was a very small amount though, perhaps the size of the head of a pin. It turned the aluminum foil it was being heated on to a large number of tiny flakes, so I couldn't examine the surface of the aluminum.

When heated on non-aluminum materials, ETN first melted, then boiled, then went "poof", shooting a noiseless jet of flame up as it combusted all at once.

My current working theory is that there is a highly exothermic reaction between ETN and aluminum at high temperatures, which releases enough energy quickly enough to create detonation conditions.

hissingnoise - 13-3-2010 at 04:55

Quote:
It was a very small amount though, perhaps the size of the head of a pin.

Surely that small quantity going off wouldn't disturb neighbours if you have any kind of walls between you.
But since you've discovered this interesting principle, the next logical step would be to devise a detonator which uses Al flakes dispersed in ETN without recourse to a primary.
A small quantity of BP could be pressed onto the mixture to ensure ignition.


User - 13-3-2010 at 05:36

That indeed is what i thought.
Would you mind performing some test with Al powder.
I have some erythritol somewhere what better to do with it than eat it, oh wait.. I could also toss it in a nitrating bath.

This would indeed, if made reliable be better than working with primary's.

chief - 13-3-2010 at 06:06

Why not discharge a capacitor through an Al-wire (which is in contact with the stuff) ...
==> That way no timing-problem any more ... (if it works)

If done right and functioning the capacitor could be throwaway, near the charge,
==> so no thick wires etc. necesary

The discharge-contact could be made via eg. a reed-relais (50 ct. a piece) ... remotely controlled by some thin wire and a 9V-Battery ...

Only: Would it be safe to have the Al over long periods in the ETN ? Maybe it would have to get a thin layer of paint or paraffine to prevent any cold reactions ...

The_Davster - 13-3-2010 at 07:40

Quote: Originally posted by hissingnoise  
the next logical step would be to devise a detonator which uses Al flakes dispersed in ETN without recourse to a primary.




The next step is to make sure the detonation does not occur between ETN and Al when stored for a while....

Perhaps also dissolve some ETN in acetone and leave in contact with Al, and separately, copper.

Perhaps repeat the experiment on Mg, see if the electropositivity of the metal has an effect.

Are you sure your ETN is acid free? Synthesis method?

gregxy - 13-3-2010 at 10:16

Maybe it is just that Al is a better conductor of heat
so the ETN heats more rapidly (or the foil is thinner etc).

Was the heating done under controlled conditions?

Melgar - 13-3-2010 at 10:28

Process for making ETN:

mix half and half fuming nitric acid and H2SO4 in a beaker in an ice bath
add erythritol bit by bit (slowly) while stirring until the liquid starts to thicken
add a little bit more nitric acid (like 10% of original volume) and see if the temperature goes up indicating incomplete nitration
if not (it didn't) let it sit for a half hour or so, then dump whole beaker into about 5X its volume of water
neutralize with ammonia, carefully, in ice bath
when pH is basic, filter crystals out of solution (crystals smelled strongly of ammonia)
rinse with distilled water, then let dry

I made two batches, one which was crystallized from ethanol, and one that wasn't. Both had the same reaction with aluminum. The uncrystallized ones are very pale yellow chunks and the the crystallized ones are white crystals.

The piece I detonated was maybe a little bigger than a pinhead, but it was as loud as a gunshot... not sure i want that noise to be coming from my house on a regular basis.

However, I have detonated ETN three times by wrapping in aluminum foil and heating it with some sort of fire. (One with black powder, one with alcohol flame, and another I just threw in some coals from a campfire, carefully of course!) I also detonated it once by just putting a bit on top of some foil and heating it over a flame.

My thought for reliable detonation was to put a little bit of aluminum-rich thermite on top, then detonate it by igniting the thermite. Another thought was to bend aluminum wire in a U-shape, then notch the base so that part gets the hottest when you run current through it. Then pack ETN powder around it. Theoretically, it would also be possible to melt ETN and pour it around the wire, but I don't plan on trying that any time soon unless I have a death wish. Still, I could heat a tiny bit of ETN in a water bath and see if that heat is enough to detonate it, which it almost certainly isn't. Maybe use a higher-BP solvent bath and try that, just to see what my factor of safety is.

Rosco Bodine - 13-3-2010 at 12:39

The materials compatability for such a mixture is a huge unknown, but it seems possible that something like a crackling microstar (dragons eggs) type of mixture
is a definite possibility here.....resulting in an increased output from what is a fulminating mixture undergoing a rapid DDT in small quantities unconfined.

hissingnoise - 13-3-2010 at 13:18



Quote:
The next step is to make sure the detonation does not occur between ETN and Al when stored for a while....

If prolonged contact with the common metals could cause detonation of ETN wouldn't we have known about it long ago?


-=HeX=- - 13-3-2010 at 13:21

I have cast ETN a fair bit. I have found I can add spherical Al to the Molten ETN, without reaction. It is a rather fun mix :)

I have had such a mix, in a small charge, for well over a year now. It was 50:50 ETN:Al, the idea was to try make 'thermobaric mix'.

However, with Al flake... ETN can make the DDT, Perhaps the Al particles cause local heating at the points, have a reaction with the ETN causing heat, then DDT?

I know a fuse through ETN, loose, in Al foil can go DDT. Not reliable though.

I much prefer the Azo Clathrate, Nitrotetrazoles, or DPNA primaries :)

My DPNA dets PETN... With ~3mg... There is 2mg Lead Styphinate used to 'Fire' it.

quicksilver - 13-3-2010 at 15:00

I have read whatever I could find on ETN, which were not only the original patents but some background studies from the USBoM & European material printed close to the time of the patents, encluding studies of ETN from DuPont and Nobel (who apparently struggled for the patent rights). Some of the material were comparisons of the various nitrated solid alcohols & their stability. I have never heard of a acid-free nitrated polyol or for that matter nitric ester in general having a sensitivity to a metal [in that there would be a formation of higher sensitivities].
Did you employ a stabilizer when recrystallizing your ETN? Did you check with more than one means, the ph of the product to satisfy yourself that the material is truly acid free? There are similarities between MHN and ETN in that they demand a ph neutral synthesis to stay stable. They both are quite stable when neutral and can be exposed to many environmental variables but heat is not one of them.

In the course of reading a particular comparison of impact & heat sensitivity, both nitrated polyols are similar to NG. This can be raised dramatically with a sample that is not acid free (USBoM 1913). A "rolling boil" can vary in temp due to container but comes close to the level of heat necessary for detonation. TTBoMK ETN has no sensitivity to aluminum. However if your sample is not acid free you could be playing with fire especially if you have not employed a stabilizer. ETN was not employed commercially due to the raw material (at the time) being much too expensive to be practical for profit. MHN was used to a limited degree but the demands for a powdered nitric ester was outweighed by the production cost of #1 Gehr dynamite.

From a standpoint of concern for safety, I suggest that you check the ph in a manner that satisfies you totally that the product is neutral. The power of ETN is very close to NG - as is it's demands for an acid-free condition. I have not heard of a common energetic material except Hg Fulminate that has a sensitivity to Al. However an acidic batch of most nitric esters eventually become "hyper sensitive" to most stimuli (heat, friction, impact, static discharge). Generally solid alcohols benefit from re-crystallization in that there is an opportunity to remove acid levels from within the particulate. Employing a stabilizer is generally a standard (Naoum -- US Railway Commission) in that they can deal with extra Nx should that be necessary (product may be neutral upon synthesis but contaminated in storage, etc.) Nitric esters were frequently re-washed due to the havoc acidic conditions can render.
Stabilizers do not HAVE to be diphenyalamine. You may use Urea, Betain ( a vitamin B), or the physical presence of an antacid (not truly a stabilizer but serves).
Be safe. If you notice higher levels of sensitivity than in the past - check until you are satisfied! However, if you are not very familiar with nitrated solids, ETN (or MHN in particular) note that they are VERY sensitive & should be treated with the same caution one would NG, Flash, or any material that demands elimination of ignition stimuli.



[Edited on 13-3-2010 by quicksilver]

Melgar - 13-3-2010 at 18:18

Another thought is that ETN is an oxidizer of sorts, in that when it decomposes, oxygen is one of the decomposition products. Now, if enough heat was generated from the reaction of this oxygen with aluminum, isn't it feasible that the reaction rate could increase fast enough to cause detonation? This would be especially true for ETN that was already near its decomposition temperature, as much of it would be.

Now, for both batches of ETN, the crystals were made basic with ammonia, then allowed to evaporate, then rinsed, then allowed to evaporate for a really long time (like a week). Now, I doubt there would be a significant amount of acid remaining because of the excess of ammonia, and any extra ammonia would have evaporated a long time ago, plus it tested neutral with test strips, so I really don't think acid is what's doing it, unless it's formed in-situ from the decomposition of the ETN.

I don't suppose anyone has a small amount of ETN to verify this reaction with? It would be at most an easier way to detonate ETN and at least a huge warning to anyone who plans to use the stuff.

quicksilver - 13-3-2010 at 21:09

While the molecule does carry oxygen ETN is not an oxidizer; it's actions when heated would most likely yield nitrogen first prior to anything. It's good to hear that you washed the yield with a basic material and did a test. However, there are exposure phenomenon such as placement in a container wherein an acid existed, etc, etc. I am only re-iterating this for surety's sake and the description of what may have been "a reaction". Principally because the last damn thing I want is for anyone to get hurt. One thing that would certainly help is a re-crystallization. ETN is interesting in that acetone is actually a bit too strong a solvent and ethanol or methanol is generally used (or a mix ). The re-crystallization opens the material to antacids and is a solid way to make sure a bit isn't creeping around in there & is the most opportune time to test for acidity.

Decomposition in nitric esters is accompanied by the release of Nx and the smell generally alerts one to that issue. Smokeless powder has been known to decompose to the point of seeing the "brown fumes" when a container is opened. Nitric esters have some similarities in that respect. Getting in the habit of using a stabilizer is always a good move. And the best opportunity to use it is during a re-crystallization. One of the difficulties when reading written descriptions is that the reader does not see the phenomenon. The material IS seriously sensitive & packs a punch: that's a fact! Likelihood is that as long as you check on it periodically & respect it like you would NG everything will be fine.

The_Davster - 14-3-2010 at 00:50

Quote: Originally posted by Melgar  

I made two batches, one which was crystallized from ethanol, and one that wasn't. Both had the same reaction with aluminum. The uncrystallized ones are very pale yellow chunks and the the crystallized ones are white crystals.


This is what I was wanting to know. While in solution during recrystalization did you do any neutralization?

As quicksilver says, base rinsing while solid can leave small traces of acid trapped within the crystal.
I am trying to eliminate the possibility of acid traces having a reaction with the metal. This would release nitrous gasses greatly accelerating decomposition.

When you said it turned orange, was it just a small layer at the bottom where it was in contact with Al, or was the pile completely orange?

Melgar - 14-3-2010 at 08:47

Quote: Originally posted by The_Davster  
This is what I was wanting to know. While in solution during recrystalization did you do any neutralization?

As quicksilver says, base rinsing while solid can leave small traces of acid trapped within the crystal.
I am trying to eliminate the possibility of acid traces having a reaction with the metal. This would release nitrous gasses greatly accelerating decomposition.

When you said it turned orange, was it just a small layer at the bottom where it was in contact with Al, or was the pile completely orange?

I checked the pH of the dissolved ETN, and it was neutral. When I put it over the flame, it first melted to a clear liquid, then the orange color started to appear from the bottom once it started to boil. But the amount was very small and the detonation followed this phase almost immediately, so I wasn't able to observe it that closely. However, I can state for certain that I didn't see the orange color when I did the same thing on steel and glass. Although, thinking about it, the steel was really dark and the glass didn't provide any contrast, so I'll have to try that again with closer observation.

quicksilver - 14-3-2010 at 10:05

What you're seeing is decomposition....This is pretty common nitric ester phenomenon. Imagine what happens with a so-called "run-a-way"......What do you see? Those red-brown fumes, right? So when you expose the material to decomposition stimuli like heat, you get a change in color. The decomposition continues....to a point; & then the material breaks down. And when it breaks down, you have an energetic reaction.
.....Sounds like all is cool & and well. The original phrasing of the 2nd post made it seem like the stuff was "going orange on you" for no apparent reason. - Thus the concern. Think of color changes that occur as a rattle from a snake; unless there is voluntary input on your part (heat, etc).

chief - 14-3-2010 at 11:17

Anyhow there was a thread on roguesci where they detonated stuff with exploding wires,
==> i.a. capacitor-discharges through thin wires ...

A larger Capacitor will have at 1 kV an amout of energy expressable in terms of "grams of TNT", and the release is just as quick as the circuit permits ...
==> So it's no big deal to create a shockwave around a thin wire ...

Has anyone tried that ? Probably much safer than handling primary-explosives ...

[Edited on 14-3-2010 by chief]

hissingnoise - 14-3-2010 at 11:28

Nitromannite is close to being a primary as it can detonate from the heat of the flame of a match.
It's a good candidate for this kind of experimentation. . .



Microtek - 14-3-2010 at 13:55

If this turns out to be a real and reliable way to induce detonation, I think you just missed out on a possible business opportunity. I can certainly think of quite a large number of uses for such a phenomenon.

User - 14-3-2010 at 19:12


Quote:

Anyhow there was a thread on roguesci where they detonated stuff with exploding wires,
==> i.a. capacitor-discharges through thin wires ...

A larger Capacitor will have at 1 kV an amout of energy expressable in terms of "grams of TNT", and the release is just as quick as the circuit permits ...
==> So it's no big deal to create a shockwave around a thin wire ...

Has anyone tried that ? Probably much safer than handling primary-explosives ...


I assume you are familiar with the term "EBW" and its complications for assembling a decent system, not saying it is impossible.
Or do you mean incorporating such a system into the Al+ETN idea, e.g. pumping a lot of power into a Al wire so that it super heats(burning or evaporating) very sudden thus detonating the ETN?


The last case I described would seem plausible.
It would be a very controllable method.


[Edited on 15-3-2010 by User]

Microtek - 15-3-2010 at 01:15

I tried a setup like that a few years ago. It wasn't a true EBW, but a piece of cardboard with a strip of Al foil glued on. The foil covered both sides, crossing a single edge. I then cut out triangular sections of the foil where it crossed the edge so only a ca. 1 mm bridge connected the two sides. Leads were then connected to the sides and two capacitors from disposable cameras were discharged through the setup.
The narrow bridge of Al foil exploded with a very sharp crack, so I tested an identical setup in a 3 mm ID brass tube with loosely packed MHN.
This produced an explosion that ruptured the brass tube, but didn't produce a large number of fragments.
So I just concluded that either it was a low order detonation or a deflagration.
Either way, with sufficient tweaking it could definately be employed in a detonating train, but the question is how much reliability you would sacrifice for a little safety.

chief - 15-3-2010 at 10:48

Of course I talk about detonating the Al-wire ...; not sure what you mean with EBW, probably "exploding bridge wire" ?

The circuit has to be quick enough, that means: Thick enough wires to conduct the energy to the point, resistivity only in the detonating wire, high enough voltage ...
==> Double the voltage at the same capacitance gives 4 times the energy, double the speed and 8 times the peak-wattage ... (linear assumptions ...), so much more meaningful to use 5 kV than 500 V ... ;

I would first try thin copper-wires: Standard-quality obtainable; can be very thin: The discharge will go through the plasma as well ...

Maybe another way is possible: Discharge through a thin layer of insulating explosive ... ; maybe with some graphite-content ...
==> Could be much quicker superheated ... (shocked ...)
==> A good insulator will need anything between 5 and 50 kV per mm, so use 5 kV at 0.1 mm ; the plasma will have pressure and extremely high temperatures, beyond that of any combustion ...

[Edited on 15-3-2010 by chief]

[Edited on 15-3-2010 by chief]

PHILOU Zrealone - 16-3-2010 at 06:31

To my feeling there are two factors that might explain the ease of D2DT of ETN in contact with heated Al foil.

Aluminium and Iron belongs to a class of metals that react weird upon exposure to concentrated HNO3...they get passivated...Aluminium displays a stonger passivation hability than Iron because it forms a protective unsoluble oxyd layer so HNO3 doesn't need to be as concentrated to lead to passivation.
The passivity is weird in that it can be deactivated for Iron by a simple contact with a metallic copper piece. The passivity of Aluminium is dependant on the nature of other dissolved components like ammonium cation, chloride anion...

1°)So it can be that during your neutralisation process with ammonia you make some NH4NO3 and that this allows the Al to be unpassived and unprotected by an oxyd layer and therefore very much more reactive (strong reducer).
Upon contact with NH4NO3, Al foil is rapidly chewed through and this oxydation process evolves heat!

I find strange that you use strong ammonia base to affect neutralisation while mild neutralisation by carbonate/bicarbonate is the favoured way to conserve the polyesterification level; strong base inducing the reverse reaction to the esterfification (nitratation); thus the hydrolysis.

2°)It can be that during the heating some ETN decomposes leading to HNO3, HNO2, NOx and carboxylic acid moeties (from the oxydation of the alcoholic functions)...then HNO2 and carboxylic acids corrodes the Al leading to unpassivation and naked unprotected Al. Aluminium salts are very prone to hydrolyse and so their pH in water is very acidic! I suppose that during the unpassivation process locally you have high acidity spots.

Melgar - 16-3-2010 at 15:24

I used ammonia to neutralize for several reasons. First, it's not really that strong of a base, at least compared to more typical bases like NaOH. Second, if you put in too much, it doesn't matter since it will just evaporate when you dry it. Third, after neutralization, drying the water gives ammonium sulfate and ammonium nitrate, both of which I can use. Fourth, the first time I did this I used baking soda and miscalculated how high up the foam would go a couple times and had it erupt all over my workbench. Fifth, I read about industrial nitration where it's neutralized with ammonia. And sixth, I have a one-gallon jug of 28% ammonia. :D

I did a set of slightly more controlled experiments and learned two things. First, aluminum does indeed produce a more powerful reaction than glass and other metals, though other materials can produce various strengths of detonation if the ETN is heated fast enough. And of course, the other thing I learned was that the detonation strength is also strongly dependent on how fast it's heated.

When heated on glass, ETN will gradually decompose into smoke. When heated on steel, ETN will actually undergo a sort of very weak detonation, where it all disappears at once but doesn't make much noise or create much force. Aluminum will give a strong detonation when heated on foil, but when heated on a section of an aluminum bar, it slowly decomposes at first, but then does the same thing as steel.

Nichrome wire wrapped in aluminum foil can also do a pretty good job of detonating ETN, as long as it gets hot quick.

I don't think there's any NH4NO3 in my ETN in significant amounts. At least not the recrystalized batch anyway. The recrystallized stuff does seem like it doesn't detonate quite as well, but now I'm starting to think that's because I use less of it because it's composed of flat, fluffy crystals. The stuff that wasn't recrystallized is in good-sized chunks, which make it easy to use more. And I don't have a scale that can measure the size weights of the ETN I'm willing to set off. So far it's all been really tiny amounts that wouldn't register on the scale.

per.y.ohlin - 16-3-2010 at 15:45

Detonation refers to a supersonic explosion. If the ETN goes "poof", it is called a deflagration. If the ETN goes "bang", and makes your ears ring, it is most likely a detonation.

hissingnoise - 17-3-2010 at 06:49

Black powder, when confined, will go 'bang' and make your ears ring but black powder doesn't detonate. . .





Melgar - 17-3-2010 at 07:45

Quote: Originally posted by hissingnoise  
Black powder, when confined, will go 'bang' and make your ears ring but black powder doesn't detonate. . .

True, but he was referring specifically to ETN.

I only called it "detonation" to distinguish from "burning", which is the same thing as deflagration, and didn't accurately describe what it was doing. ETN definitely detonates when heated quickly on aluminum foil in quantities larger than a match head though. I'm thinking of mixing some Al powder with melted ETN and running a piece of nichrome wire through it to see if it makes a feasible detonator. In any case, I wouldn't melt ETN with anything other than a water bath, since its melting point is about 80C. Or maybe it would be safer to coat the nichrome wire in glue, then dip it in Al powder, since this would limit the interaction between the ETN and Al more.

hissingnoise - 17-3-2010 at 07:50

Yes, but sometimes what sounds like a detonation may just be a 'fast burn'.
The crack of a rifle, for instance. . .
ETN melts at ~61*C but if you're adding Al flakes you need to do the melting remotely, just in case!





[Edited on 17-3-2010 by hissingnoise]

per.y.ohlin - 17-3-2010 at 12:29

I know bang does not always mean detonation, but with a small quantity of unconfined ETN I cannot image a bang being deflagration.

User - 17-3-2010 at 12:41

In this case i agree with you, MHN and ETN do not have explosive deflagration, at least unconfined.
They might be sensitive but are definitely not primary's.
Its easy to test because deflag. will do next to no damage compared to a detonation.
BP+ETN is very unlikely to det.

Rosco Bodine - 17-3-2010 at 13:03

Look for metal shattering and cutting brisance being demostrated by energetic materials which are known to be capable of that, or else don't be too sure about what is the nature of the bang you may hear is a "detonation". And there are
different orders of detonation possible also. Speculation about what only a
witness plate or other good experimental results may show is no more than mere speculation, until you have the evidence provided by test materials which are
revealing what speculation cannot tell for sure.

Melgar - 17-3-2010 at 16:01

Well, the one time I detonated ETN on foil, it was loud enough to make my ears ring and it turned the aluminum foil I was heating it on into tiny bits of glitter. Again, I'm a bit apprehensive about trying more experiments since even a very small amount of this stuff will make a noise loud enough for my neighbors to hear.

Rosco Bodine - 17-3-2010 at 16:34

How "loud" is an explosion is not really a definitive measure of performance.
There are some compositions that are really loud and you would expect to find
that there was a high order detonation, but there actually wasn't when the
evidence is examined. Really, honestly it does require definitive tests to
determine for certain what the energetic material has done in the way of "work"
on the target, and everything else is guessing. Also the smaller quantity being tested, the less likely it becomes that an actual high order detonation occurred because there is a "critical mass" requirement which varies according to the conditions and the particular energetic material being tested. If you have neighbor worries, then you don't have a safe environment to be conducting any tests necessary to get good data.

PHILOU Zrealone - 18-3-2010 at 03:46

Quote: Originally posted by per.y.ohlin  
I know bang does not always mean detonation, but with a small quantity of unconfined ETN I cannot image a bang being deflagration.


A "bang" is simply the noise from a shockwave going faster than the speed of sound...thus slighly faster than 350m/s (1250 km/h) will make a bang!

As stated Rosco, if you are unconfined and in very tiny amount...the chance for a detonation to occure from D2DT is very low because each explosive compound displays specifically what is called a critical diameter of detonation (lowest diameter of a charge at what a detonation (proven by a witness plate) occurs) below this diameter only deflagration occurs. This diameter is defined under confinement...if unconfined it goes up significantly and so does all linked parameters...inclusive the critical mass!

Dc = critical diameter of detonation
Vc = Dc*Dc*Dc = critical volume of detonation
Mc = Vc/d = critical mass of detonation

Important note:Don't confuse the critical diameter of detonation (Cdod) with the critical diameter of the steel sleeve test (Cdosst)...the later being an evaluation of the confinement needed to perform deflagration or detonation of an explosive under direct heating of an iron steel container from flames.
There is an inverse proportionality rule between the later and the former!

Cdod = K(constant)*1/Cdosst

So NH4NO3 has a high Cdod (a few inches) but the lowest Cdosst (1mm) and Nitroglycerin has a low Cdod ( in the order of mm) and the maximum Cdosst (24 mm).

[Edited on 18-3-2010 by PHILOU Zrealone]

quicksilver - 18-3-2010 at 12:05

Quote: Originally posted by hissingnoise  

The crack of a rifle, for instance. . .


There is a very interesting issue in hand loading that many people call a "detonation". This takes place where a substantially LOWER level of smokeless powder is charged in the cartridge and the result is a catastrophic head case separation & occasionally extreme damage.

There are some complex questions this gives rise to.

Now whether this IS a true detonation or not is something that has not been published in common reloading material; but what takes place is obvious. The volume in the cartridge increases so that the primer's effect on the NC/NG is such that the case cannot contain the power of the explosion. we know that there is a "weak spot" (the seated bullet) purposely designed to use the energy as a work format.
If the that material simply burned - developed gasses, etc, why would the case web not be able to contain the thrust of these gases? The result is not only an insepent case separation but in some instances, a blown receiver or other material damage that occasionally seen as a "shattered" firearm, & at other times a "peel" of the surrounding material. {This is very important as it illustrates the strength of the explosion.} At other times (to make this more complex) the case is separated and the bullet travels through the barrel. That result looks similar to "tired brass" but yet it had occurred with new material and an extreme undercharge.

Remington briefly studied this phenomenon in the mid-1960's when it made more of it's brass available and it was studied again in the early 1990's by independent researchers in the .40S&W when a great deal of Glock pistols had some troubles.

The two issues were vastly separate in that Glock chose not to fully support the cartridge in their chambers but one issue was clear, that pressure spikes -HIGHER than could be dealt with by the brass & steel were occurring with LESS energetic material than would be appropriate to yield such a result.
Two questions came to light. 1.) does this situation of a vastly low powder charge create a DDT? Or 2.) Is the term "propellant" a misnomer, in that a managed explosion was not allowed to mount to full detonation through either lack of available oxygen (volume) or can a detonation be halted in a manageable way to provide force via gases & a primer that is not truly a "detonator design". Does an enormously strong casing exists in a modern firearm but within that casing a "plug" or escape valve exists to accomplish work by interrupting or slowing a chemical decomposition?
I thought the whole issue fascinating & the fact that much material is "trade secret" (out of prying eyes) by *Remington & *Winchester's new short magnums whetted my appetite for more information.
Many of the data gathering mechanisms have been complicated by primary energetic material like silver acetylide which yields no gas when it explodes. It simply breaks down.

The noise is obvious but appearance made by the molecule's degeneration at speed. It fact it would air in it's degeneration front and this "may" be the reason it has sound, yet it does not form gases


* In many of the reloading material of the newer "short magnums" there are strong warnings about loading too low.
What's more for generations there has been very direct warnings directly dealing with this subject in loading magnum pistols too low

[Edited on 18-3-2010 by quicksilver]

Gamester - 18-3-2010 at 22:33

Quote: Originally posted by Melgar  
Anyone have any experience with this?


Yes, I have. The ETN detonates. Surprisingly small amounts detonate. I was very surprised. I started with a pin head size wrapped tightly in a small piece of foil about 3 mm square. I placed it on a stove burner, turned it on and waited. A minute later there was a sharp crack, surprisingly loud. The foil disappeared. The burner was coated with a very thin film of silver where the foil had been. It looked like aluminum had been sputtered on electrically. I noticed a slight stinging feeling in my thumb. A foil splinter less than the diameter of a hair was sticking in my thumb. I pulled it out with tweezers. It was in two thirds of its 3 mm length. I was wearing safety googles by no other protection because the amount was only 5 mg or so. I tried this again with a piece the size of a split pea. I stood behind the refrig. The bang rang my ears. It put a dent in the burner element and bent the entire element downward enough so that a pot no longer sits on it without wobbling. For the next few weeks, wherever I looked in the kitchen I would see just barely visible dots of aluminum which had been reduced into a dust, floated in the air and then settled. The pieces were much, much finer than you would see in the finest atomized aluminum dust. They were both detonations. I guarantee you that. The power was to extreme, the destruction of the foil too complete.

Melgar - 19-3-2010 at 04:53

Excellent, someone can confirm my findings. I guess now we just need to figure out how to use these properties to make a relatively safe detonator.

quicksilver - 19-3-2010 at 07:13

Melgar :

Professional "exploding Bridge-wire" detonators utilize blast box designs that are quite expensive. One has an inverter and it used with an automobile or truck another is self contained; but they are not small - nor are they cheap. They range from about $1200 + through 2-3k.
The object is to not only push a great deal of current through the device but to recognize the fact that often a LONG distance of wire will act as a resistor. Especially if it's thin. If it's heavy gauge it will cost quite a bit. Therefore the Nonel concept.

If you didn't want to go that route you could use co-axial cable for a capacitor burst but the cable will certainly have a life. It will need to be inspected often and the ends will be lost. Today, industry uses relay boxes of scrambled signal that's encoding process keeps someone from "dialing the wrong number" on a cell phone. This cuts both the wire issue down to reasonable cost and security maintains itself. but just shooting a bank of photo-flash capacitors down a wire is not going to work well UNLESS you have at the bridge-wire terminus an actual resistance wire such as Nichrome, which is a resistance point as opposed to the rest of the lead. Do NOT be dissuaded to use steel wool or some super thin piece of wire, etc. They will corrode, break, & may not actually focus the point of highest energy where you need it.

If you want to see some god ones check out a search for "Blasting, industrial, Nonel, safety ignition". I don't want to make a link as this is a simple discussion and the company's have concerns of their own, etc.*

You actually could get the effect if you had a automobile inverter with a circuit-breaker @ about 700 watts and make a lead less than 200yds with whatever wire for the lead and leg wires. but that bridge wire needs to be the real thing.



* see a company named Ideal.
One of the reasons why these blast boxes are so expensive is that they put out BOTH current & voltage. They are pretty much lethal @ 1500-2500V & .250ma. And they often use a Ghz frequency that is both encrypted and has a fairly decent transmitter (they can exceed 5 watts).

[Edited on 19-3-2010 by quicksilver]

chief - 20-3-2010 at 03:30

For a quick blow the peak-Wattage has to be maximized.

That means all the circuit has to be low-resistivity:
==> e.g. 1 Ohm of overall wire-res. will at 1 kV permit a current of 1 kA, giving a mximum of 1 MW, that cannot be exceeded
==> 1 Ohm at 5 kV will permit 5 kA, thereby the limit would be 25 MW ...
==> 0.1 Ohm at 5 kV would permit even 50 kA and thereby 250 MW (though in reality probably limited by inductivity, both of the capacitor and the wires; also violent magnetic fields would lead to dangerous effects) ...
==> But in contrast the photo-capacitor-bank with maybe 500 V would at 1 Ohm only permit 500 A, thereby only 250 kW peak, quite lame in contrast to the higher Voltages

The higher the potential peak-Wattage, the quicker the discharge ...

So the optimum voltage is probably several kV, and the capacitor may even be not too big: Standard caps, which are rated for maybe 500 V, will at least one time each withstand a multitude of that ...


... to be continued ... : Blumelein-Circuit etc.

Melgar - 20-3-2010 at 18:21

No, no, no. I'm not talking about an exploding bridge charge. I'm talking about using 5VDC to heat a nichrome wire coated in aluminum and detonating ETN. I know this can be done because I did it myself with a very small amount of ETN. If I did it myself with like 5mg, perhaps with a larger amount, it could be a primer for a more powerful charge. It would certainly seem to be safer than a lot what's currently available.

chief - 20-3-2010 at 23:20

... continuation from above:

Expensive parts are not necessary, except one DC-charger ...
==> As said above: Each standard-500V-rated capacitor will withstand several kV before breaking ... ; this though does not count for electrolyticals (which are useless for the purpose, since they withstand only maybe 30-50 % over-voltage) ...
==> So one really high-voltage cap will be charged to maybe 5 kV, and then the circuit will be closed, blowing the 500-V-specimen ...

The circuit I initially would construct for the experiment would look like this:
(+ 10 kV) )------(cap1)-------(wire)-------(cap2)------( (- 10 kV)

What happens then is: The 500-V-caps will have been charged to maybe 2 kV, maybe even 4, and in the moment of failure the one that blows first
==> shorts thereby out, permitting half of the energy stored in the other cap. to quickly flow through the wire, thereby detonating it ... if the wire is thin enough for the charges ...

Those 10 kV, mentioned in the circuitry, may come from some standard TV-anode or whatever, and be transferred to the location via coaxial cable ...

Also I would add another cap:

deton.png - 16kB

Cap 3 would have bigger capacity, be close to the location and ensure quick discharge, since the energy would flow through the comparatively small circuit thereby formed, however long the coaxial cable would be ...

]

[Edited on 21-3-2010 by chief]

FrankRizzo - 21-3-2010 at 08:02

Guys, he's *not* talking about EBW detonators. There are already threads on that subject; for the layperson to construct the firing circuits is not a trivial task. Please get back on topic.

Melgar - You might try doing a few experiments where you mix varying percentages of blackhead aluminum with a small quantity of ETN. Holiday light strings provide a cheap source of heating elements. Some brands of plastic straws also fit snugly over the glass envelope of the bulb from a holiday light string, making easy disposable assemblies for testing.

User - 21-3-2010 at 08:42

Quote:



No, no, no. I'm not talking about an exploding bridge charge. I'm talking about using 5VDC to heat a nichrome wire coated in aluminum and detonating ETN. I know this can be done because I did it myself with a very small amount of ETN. If I did it myself with like 5mg, perhaps with a larger amount, it could be a primer for a more powerful charge. It would certainly seem to be safer than a lot what's currently available.


Sorry to interrupt but this guy is right, I don't understand how this can be unclear...
There is plenty of stuff about EBW's and similar systems lets not waste this thread on that kinda stuff.
The whole deal is that if he's right we do not need a complex and expensive unit.

gregxy - 21-3-2010 at 10:29

There are two applications.

If timing is not critical use the nichrome wire
or Xmas tree bulb as the heat source. The most simple reliable power source
is just a battery. Something like 4 "D" cells in series should work fine, no need
for any electronics. To be safe connect two normally open push button switches
in series with the battery. That way you need to push both of them to set it off

If timing is critical (on the milisecond scale as in for a FAE setup) then something
like an EBW is needed. A disposable camera contains a 120uf cap which is
charged to 300V by the circuit in the camera. 0.5*120e-6*300^2 = 5 joules of
energy stored in the little cap. This is equivalent to dropping a 1kg weight about
18 inches. If you could deliver all of this energy to the detonator it would easily
set off ETN. I recommend mixing the ETN with enough Al powder to make
it slightly conductive. Then get some cheap speaker wire and strip just a tiny bit
off the end this will create a gap of about 0.128". Somehow imbed the end of the
wire pair into the ETN/AL. This way the current must pass through the ETN
and hopefully most of the heating will occur there. Using the disposable camera
for power see how long you can make the speaker wires and still have it work
reliabily.

Here is a website on how to use disposable cameras:
http://www.jeffhove.com/robots/coilgun.html



[Edited on 21-3-2010 by gregxy]

chief - 21-3-2010 at 11:15

Anyhow: If it really works with Al for mysterious reasons ...
==> ... then those reasons may probably be found in the electronic structure of Al, which likes only 3fold bonding: So whence an Al-atom once is activated for 1 electron it just "dumps" 2 others, or so to say "requires" immediate 3-fold bonding ...,
==> whhich sort of inversely mirrors nitrogen ... ; maybe in ETN the N-alignments are specially sensitive to that ...

[Edited on 21-3-2010 by chief]

chief - 21-3-2010 at 14:50

As I understand from above the effect occurs with foil, but not with thicker Aluminum:
==> That means (probably) that an exothermic runaway needs to be possible, which would be hindered by the good thermal conductivity of thicker aluminum ...


Melgar - 21-3-2010 at 18:15

Quote: Originally posted by chief  
As I understand from above the effect occurs with foil, but not with thicker Aluminum:
==> That means (probably) that an exothermic runaway needs to be possible, which would be hindered by the good thermal conductivity of thicker aluminum ...


Yes, that could be the case, coupled with the fact that there would be more loss of ETN from thermal decomposition when heated more slowly. I think I'll need to try some more experiments next time I get a chance, maybe by burying each test detonator under a foot or so of dirt. That'd probably minimize the loud noises, plus it's about time to dig up the garden and get it ready for planting anyway. :)

hissingnoise - 22-3-2010 at 04:12

Tillage by IED, Melgar?
Ideally though, such testing should be done well away from built-up areas. . .


[Edited on 22-3-2010 by hissingnoise]

Melgar - 22-3-2010 at 07:09

Just detonated about half a gram of ETN underground. I started with a piece of 0.5 inch OD polyethylene tubing, then used a flame to melt and seal one end. I put the ETN inside, then heated it in a water bath until it melted. Then I took two pieces of nickel/titanium wire and ran about a half inch of 35 gauge nichrome wire between them. Applying 5VDC caused the wire to glow yellow. Then I immersed the nichrome wire in some powdered aluminum and hooked up the voltage again. This had the effect of melting aluminum onto the nichrome wire. Then I melted the ETN again and carefully immersed the nichrome wire and the other two wires into it. Once the ETN solidified, I melted wax and used that to seal the top of the tube. Then I got some speaker wire and hooked it up to the two NiTi wires, then ran it about 20 feet away. The first time, there was a bad connection so I wired everything up again. The second time, I touched the wires to a 9V battery, and I heard a deep "boom" and the dirt above where I buried the ETN lifted up about half an inch and fell back down. I dug it up and found the half of the polyethylene tube that didn't have ETN in it. All around it were these tiny white specks too. At first I thought they were undetonated ETN pieces, but on closer examination they appeared to be polyethylene.

The way I detonated it was probably not the most efficient, and I don't think the detonation used all the ETN, but it did certainly appear to detonate. I think maybe the aluminum fused to the nichrome wire and made it more conductive. This seems like it'd result in a weaker detonation. I think next time I'll try mixing Al powder with the ETN directly, then using plain, uncoated nichrome wire to provide the heat.

chief - 22-3-2010 at 13:18

Are you sure the Al melted onto the Ni/Cr=wire ? Usually the oxide-layer prevents this ...; on the other hand there exist an reistivity-alloy made from Ni and Al ...

The oxide layer of Al however is no big deal for HCl, so maybe if chlorine would get into the mixture ...
==> What about mixing ETN wih Al-Powder and a Chlorate ? (dangerous dangerous ...)

Melgar - 23-3-2010 at 06:10

Quote: Originally posted by chief  
Are you sure the Al melted onto the Ni/Cr=wire ? Usually the oxide-layer prevents this ...; on the other hand there exist an reistivity-alloy made from Ni and Al ...

The oxide layer of Al however is no big deal for HCl, so maybe if chlorine would get into the mixture ...
==> What about mixing ETN wih Al-Powder and a Chlorate ? (dangerous dangerous ...)

Yeah, the surface of the wire was all thick and lumpy, and the same color as the Al powder, although in retrospect there probably wasn't an electrical connection between them. Mixing ETN with an oxidizer does sound pretty dangerous, although I haven't used chlorates to know how reactive they are. What I do have is potassium permanganate, and I know I sure wouldn't want to mix that with melted ETN. I was thinking of trying to use a Al/KMnO4 based flash powder to set off the ETN, but I suspect that wouldn't be very stable and I'm not interested in learning it the hard way. Besides, setting off ETN with flash powder has already been done many times. I guess the next step is seeing if an Al-ETN mixture will detonate from the heat of a nichrome wire. The reaction between Al and ETN doesn't start until ETN is boiling, so as long as a water bath is used to melt ETN, doing this doesn't seem to have a significant detonation risk.

ETN Detonation, Everyone should take a look at this.

Forumdude - 18-3-2013 at 20:14

So I sucsessfully nitrated and recrystalized ETN and I order these nice little EBW type things, they are a thin piece of metal soldered to two pieces of copper wire and then sealed with a piece of tubing

The nice tubing is from a 9volt battery, I took it apart and cleaned out one of the tubes from the inside of it.

I first loosley packed the clear tubing with ETN then inside the tube it was packed with a flashpowder then a packed layer of ETN that was packed using a arbour press to around 1500psi.

I then crimped the EBW or the heating element inside the tube.

The heating element was then powered by many disposable camera capacitors and a circuit board from one.

You can buy the heating elememts at http://martinezspecialtiesinc.com/

They ar dirt cheap

rsz_1photo_2.jpg - 70kBrsz_11photo.jpg - 73kBrsz_photo_1.jpg - 78kB

dangerous amateur - 19-3-2013 at 04:20

If it works like an EBW, whats the flash for?

I do not think this design will be reliable. I played around with ETN a lot and tested many ETN-only caps, but there where never 100% reliable, what is extremely annoying.

I've given up. Better protect yourself properly and use double salts etc.

Ral123 - 19-3-2013 at 05:41

Video or it didn't happen :P Isn't the case from 1.5v AAA battery?

Forumdude - 19-3-2013 at 08:20

Hahaha I will post a video tonight , I set 6 of them off and all but one worked. The flash? And the casing is from inside a 9volt there is many little AAA size battery's , I suppose a AAA would also work fine. Those EBW would probably work with primary's also just on a lower voltage , they glow red when they are put on a lower voltage.

[Edited on 19-3-2013 by Forumdude]

dangerous amateur - 19-3-2013 at 08:38

This is NOT an EBW.

Quote:

I set 6 of them off and all but one worked


Yeah, they made nice bangs. But proper DDT?
I doubt it.


Forumdude - 19-3-2013 at 10:10

Yeah a nice bang. Have you achieved Def to det on any of your ETN only caps? It's not a EBW , there is a little Element that gets instantly red hot.

[Edited on 19-3-2013 by Forumdude]

Bot0nist - 19-3-2013 at 19:55

lets see some controled tests agianst witness plates. It seems your flirting with the ETN "NPED" idea. Search, it has been done to death. IIRC, thermal shock, and not direct ignition is the best way. else, to much material deflagrates. Good luck, and be safe.

Try a small tube with pressed or casted ETN, of minimal diameter, with a piece of good BP fuse completely covered in a few layers Al foil imbedded in it. Ensure that no flame or spark can directly contact the ETN. just the rapid heating from the foil.
(Holmes?, lol)

Ral123 - 19-3-2013 at 22:18

I didn't know that ETN goes high order from thermal shock. I though it deflagrates and we can only hope for it to ddt.

Bot0nist - 20-3-2013 at 06:08

It is well known and recorded that small quantities of ETN will readily undergo detonation when confined in Al foil and strongly heated. Read the thread, "ETN: Almost killed myself" for an example of a few mgs detonating in a glass test tube, to devastating effect, from rapid thermal shock.

Ral123 - 20-3-2013 at 08:10

And how efficient this detonation is and how reliable/predictable? Primarys are reliable to initiate high order certain secondaries. Many gun powders are NG/NC and would also explode, but not detonate under such heating.

Bot0nist - 20-3-2013 at 10:28

I never claimed that it is more reliable or "better" than using the time tested standard of a primary explosive induced "train" for initiation of insensitive secondary and tertiary explosives. Only that ETN readily undergoes full detonation when small amount, confined in foil, is rapidly heated. I, myself, am not a fan of "NPEDs," but they have been researched and tested to death, both in the industrial, military, and hobbiest settings. A few well worded searches should garner more information than you would ever need on the subject.

Forumdude - 20-3-2013 at 16:28

Quote: Originally posted by Bot0nist  
lets see some controled tests agianst witness plates. It seems your flirting with the ETN "NPED" idea. Search, it has been done to death. IIRC, thermal shock, and not direct ignition is the best way. else, to much material deflagrates. Good luck, and be safe.

Try a small tube with pressed or casted ETN, of minimal diameter, with a piece of good BP fuse completely covered in a few layers Al foil imbedded in it. Ensure that no flame or spark can directly contact the ETN. just the rapid heating from the foil.
(Holmes?, lol)


Holmes? What?

Bot0nist - 20-3-2013 at 19:00

Nevermind. There once was a character in a mostly fiction tale around these parts, who was near obsessed with ETN thermal shock caps, NPEDs, etc, among other, ummm, eccentric intrests and quirks. It was just a wierd joke on my part, to see this come up agian.
see my sig.
No shots at you, at all intended. Im just a bit odd.

Kalium - 20-3-2013 at 19:08

Quote: Originally posted by Bot0nist  
Nevermind. There once was a character in a mostly fiction tale around these parts, who was near obsessed with ETN thermal shock caps, NPEDs, etc, among other, ummm, eccentric intrests and quirks. It was just a wierd joke on my part, to see this come up agian.
see my sig.
No shots at you, at all intended. Im just a bit odd.

Oh, he's still around. Just not actively posting.

dangerous amateur - 21-3-2013 at 01:22

If someone likes to develop such things for fun, why not?

I think it is doable, my caps, or rather little pipe b!mbs worked fine. I compared them with double salt/etn caps on steel plates and also with small ammonal charges and they worked fine.

However, I did not do enough tests to be 100% sure.

If you do an laborious experiment with energetic material and it is ruined because the cap did not work not properly (but maybe properly enough to f!ck up your work) you will see that homemade NEPDs are not worth the effort.

Invest the same effort in proper DS or LA caps and you'll be pleased.

[Edited on 21-3-2013 by dangerous amateur]

Hennig Brand - 3-6-2013 at 04:55

The small metal tubes from the 9 volt battery are actually AAAA (quadruple A) batteries, not AAA (triple A) batteries. This size is not nearly as common as the AA and AAA types, being used for certain laser pointers and a couple of other applications. A bank of them welded together is commonly found in 9V batteries though as we have seen.

From reading on these forums the last few years a little primary explosive pressed on top would seem to be much more reliable than the no primary options with ETN.

[Edited on 3-6-2013 by Hennig Brand]

Antiswat - 3-6-2013 at 06:34

i think if you want it to be more reliable you should use a slowflash or star composition or... rocket fuel as in rocket candy, using slow burning mixtures will shockheat the etn and thus making a small delay from you flick the button till it will go off
you can also try with copper oxide as it generates extreme amounts of heat in small amounts (sensitize it somehow?) as i experienced CuO + MgAl or GD Al (1-3µm) isnt really sensitive liuke everybody claims it is
you could make a 1:1 KMnO4 CuO oxidizer and mix with MgAl perhaps? that would work very well im sure
problem with flash initiation is that you just want it to have a container that can hold in the pressure until its supposed to go off all at once as flashpowder is alot less brisant than most primary HE's

Varmint - 12-6-2013 at 03:44

Assuming that cell casing is from a dry cell 9V, the case is zinc, and there is no way I'd use zinc in any initiator.

DAS

ETN detonation without a primer

Krakermanworks - 16-1-2014 at 01:51

Hi I've heard etn can be detonated with just al foil, and rcandy (60:40 kno3:sugar) has anyone had success with this or other similar methods of detonating etn, I don't want to use primers as the only primary's I can synthesis are hmtd/tatp wich I'd rather not use.

[Edited on 16-1-2014 by Krakermanworks]

Fuse - 16-1-2014 at 02:27

Yes, in past I used the procedure in the picture

ETN CAP resized.JPG - 50kB

underground - 16-1-2014 at 02:49

What is that green one think like string ? visco fuse ?

markx - 16-1-2014 at 03:00

It may work, but I have found it excruciatingly unreliable.....I have not tried the exact method on the picture but similar setups:
100-200mg ETN rolled up in Al foil, surrounded by a pyrotechnic mass (meal powder bound by rubber cement)
100-200mg ETN with flash charge on top in direct contact/separated by foil
100-200mg ETN hermetically sealed in capacitor casing (Al cup) surrounded by pyrotechnic mass

Results were around 2-4 times out of 10.....mostly deflagration or partial detonation. I did not try the direct addition of Al powder though, it might hold the key to a more reliable initiation.

Fuse - 16-1-2014 at 03:14

Sorry for incomplete informations..

Green string is 2mm visco fuse and foil is aluminum foil for cooking.
Aluminium powder increase ETN sensibility (i think not in chemical therms but helps heat transmission).
ETN must to be packed airtight.

A common problem that involves only deflagration can be:
1) ETN not well packed
2) visco fuse during burning make a hole in the ETN containing foil
3) visco fuse burning can't generate a lot of heat

You can put inside more pieces of visco fuse than the illustrated in picture, this increase the heat generated helping detonation success

underground - 16-1-2014 at 06:00

Some mgr of HMTD sounds better than all of that...

Fuse - 16-1-2014 at 06:57

HMTD is an organic peroxide, avoid to use them.
Also, it is extremely sensitive to friction.

Zyklon-A - 16-1-2014 at 07:26

The Al also burns, because ETN has a + oxygen balance at detonation.

underground - 16-1-2014 at 08:01

It is said that AL decrease the performance of ETN

Antiswat - 17-1-2014 at 03:24

true, underground.. it doesnt take part in the detonation but rather in the gas cloud after the detonation
however, a person i know to have initiated ETN with simply standard visco fuse tried adding red phosphorus, he says it shortens the DDT alot, unconfined.. perhaps this could be useful if a source of phosphorus was found?

otherwise, other thread about ETN i described overkill of ETN using rocket candy mashed into thin plastic tubes (straws?)

if you overkill it you will find it reliable

not to mention blackpowder and other slowburning compositions should work aswell

EBW also, and PVC hose filled with rocket candy, hole cut in side and 0.5g ETN packed in al foil inserted in hole then taped has proven to work 100 / 100 times (supposing author actually tried this 100 times)

perhaps flying fish fuse or similar? (a fuse containing slowburning star composition)
anyhow 3 sparklers with 0.6g ETN wrapped around it in al foil should give you some result

Krakermanworks - 20-1-2014 at 14:50

I think the setup would work better if the visco attached to rocket fuel because I've seen that get very hot easily melting wood in a short space of time, thanks will come up with a reliable etn detonater shortly nd reply back in a couple of days. Thanks

Turner - 20-1-2014 at 19:12

Try silicon powder and KNO3. Search in YT for 10 finger club video, it has a diagram of a NPED that was almost to the point of being reliable but barely just not there. It is something that ought to be studied and researched.

I made NPED's that worked 4/5 times.

BTW, I believe MHN would be a better explosive for heatshock detonating than ETN.

Krakermanworks - 21-1-2014 at 10:25

Thanks, I can't find OTC silicone powder though :(


image.jpg - 29kB

Antiswat - 21-1-2014 at 11:21

if the visco would be attached to the rocket fuel and the aluminium foil containing ETN would be wrapped around you would either need a long piece of rocket candy (danger of it breaking apart) or a shittonne of luck or hatred for reliability

the fuse would run near the ETN/Al foil and make it blow apart in 0.01g amounts effectively destroying the charge and blowing the fuse apart / away

also.. silicone i dont recall being available OTC, its used for pyrotechnics, unless if you live in EU then i dont know where you can get it; simply try pyro sites, the setup looks more tricky and i just dont feel reliability in fuse to KNO3/Silicon..
i tried KNO3/silicon just because why not packed in al foil and i was using wrong ratios, although it didnt seem very heat sensitive so you need something like a sparkler or star composition at the tip of the fuse to get decently reliable ignition, not to mention to keep in mind that you dont want the fuse to get TOO wet as this will also have a go at the reliability

Krakermanworks - 12-6-2014 at 01:08

I simply used kno3/sugar ball milled for an hour or so and used the diagram above, I can't say reliable but worked 3 out of 4 times and the time it didn't work I didn't compress the kno3/sugar to the packed etn

Motherload - 27-6-2014 at 23:14

I have a few mini rocket motors. I can stuff a mini Al foil capsule containing ETN in them. Is that enough heat ?

ETN NPED Challenge

Hey Buddy - 17-11-2022 at 13:14

Okay. That's it. I'm dragging out this thread. Going to study ETNs fascinating thermal idiosyncrasies in effort hammer down ETN DDT.

First step, working out foil phenomenon since it's an experience that pretty much every ETN user goes through.

First questions to understand are:

1) To what degree is foil ddt phenomenon permitted because of material interaction?
1a) Is foil ddt replicated on other metal foil surfaces that are non-Al?
1b) Is foil ddt replicated on non-foil Al surfaces, such as heated bar stock?
1c) Can foil ddt be replicated on any other thin foil-like surface other than metal? ie. ceramic/glass/plastics/kapton/metalloids/oxides

2) What are the circumstance under which ETN reliably DOES NOT ddt, where it seems to nearly always deflagrate and never detonate?

That's what to attack first: "where is the ETN ddt, where is it not."
Will be conducting some tests. Will post results.

ManyInterests - 17-11-2022 at 15:28

Thanks for finding this thread Hey Buddy.

Since ETN is my (currently) my preferred booster energetic and all my attempts at melt-casting ETN were so far done in plastic pen bodies (which I learned aren't good enough), I will be doing melt-casting ETN in steel tubes and brass shell casings. I want to know if using an aluminum tube for melt-casting ETN poses danger of detonation? I melt cast by putting the case in water heated to the melting point of ETN, which is around 65C.

I asked this question previously. I just want reconfirmation.

Hey Buddy - 17-11-2022 at 15:38

Quote: Originally posted by ManyInterests  
Thanks for finding this thread Hey Buddy.

Since ETN is my (currently) my preferred booster energetic and all my attempts at melt-casting ETN were so far done in plastic pen bodies (which I learned aren't good enough), I will be doing melt-casting ETN in steel tubes and brass shell casings. I want to know if using an aluminum tube for melt-casting ETN poses danger of detonation? I melt cast by putting the case in water heated to the melting point of ETN, which is around 65C.

I asked this question previously. I just want reconfirmation.


If no one else has an answer, I can just test this for you. Will be in lab tonight, have Al 8mm casings and ETN and Al powder. I can melt a 50:50 Al/ETN mix and straight ETN both in aluminum 8mm casings?

edit: how do you melt the case in water? in end-closed aluminum cases directly submerged into water or casings inside a test tube in water?

[Edited on 17-11-2022 by Hey Buddy]

ManyInterests - 17-11-2022 at 15:45

Take good care... and please take precaution in case something goes wrong. ETN is pretty powerful stuff.

Hey Buddy - 17-11-2022 at 15:51

Quote: Originally posted by ManyInterests  
Take good care... and please take precaution in case something goes wrong. ETN is pretty powerful stuff.


I wear body armor and helmet, faceshield. ear protection, kevlar gloves, use heavy pavers as blast shield etc.

See above edited question on how you are melting so I can replicate?

EDIT: I see your response below. Im just responding here to avoid new post. --I dont think I have closed end casings in Al. I do have SS closed end casings, I can do a 50:50 aluminum/etn in SS body in water. Aluminum casing will have higher emissivity than SS but it will simulate it well with intermixed Al. I will take temp up higher than ETN mp, maybe about 85 C or so, that way it will be well past the mp and simulate a more extreme environment than you intend to use.

--Yes. ETN is an angry ex wife in melt phase. The first time I made ETN, I was more naive then, and used to hammer test and then Al foil burn test, HOLDING THE FOIL from the fingers. After my introduction to ETN, that test procedure got changed quick. I didn't know about SM then. ETN in melt phase under a 2.5 kg drop hammer, goes from 14 cm impact height down to 1 cm. Possibly even a little under 1. It's among the most sensitive explosives in melt phase. Some people are comfortable with pouring/handling it with their human hands, but personally, I would recommend not moving the explosive in melt phase and letting it melt and cool in place, as a general safety. You can lessen cooling time by reducing the mass of water. Its sensitivity is reverted back to normal sensitivity as soon as it's all the way back in solid phase.

If it needs to be poured, I recommend making a pouring crucible that gives a little standoff with a wooden stick, (no metal). That way if you make a mistake, there is a small bit of standoff to avoid the primary blast injury. Wooden splinters are so low mass they aren't generally that bad. I used to do a lot of explosive breaching in a previous life, and breachers using detcord commonly get wooden door fragments in the skin in face/neck and wrists from controlled detonations, some douglas fir doors really splinter and depending on standoff, it kind of looks like you tried to hug a porcupine. 2ndary blast injury fragments, hearing, etc are no joke either but they are much less devastating long term than a primary blast injury which will roast beef your anything, assuming you survive an accidental detonation in a lab.

Attachment: ETN MELT CAST SENSITIVITY CHAVEZ.pdf (295kB)
This file has been downloaded 31 times

[Edited on 18-11-2022 by Hey Buddy]

ManyInterests - 17-11-2022 at 16:46

I heat the water in a beaker on my heating mantle until it hits 65C and then I use a small three prong clamp to keep part of the case up while I submerge the lower part (where the ETN is) in the water. It takes around 5 or 6 minutes for everything to fully melt. The plastic pen body I used took around 6:30 to 7:00 minutes to melt, a metal case will probably take 5 minutes or so due to the superior thermal conductivity of the metal.

After they melt, I gently remove the case and set it aside for to cool down to room temp. I wait around 25 minutes or so. Give it 30 minutes if you're using metal since I don't know how long it'll take to fully cool back down and solidify. But once you remove it and set it aside it should already be safe from detonation since it is already cooling down the moment you remove it. But take precaution anyway. ETN is much more sensitive when melted.

B(a)P - 17-11-2022 at 17:40

Quote: Originally posted by ManyInterests  
I heat the water in a beaker on my heating mantle until it hits 65C and then I use a small three prong clamp to keep part of the case up while I submerge the lower part (where the ETN is) in the water. It takes around 5 or 6 minutes for everything to fully melt. The plastic pen body I used took around 6:30 to 7:00 minutes to melt, a metal case will probably take 5 minutes or so due to the superior thermal conductivity of the metal.

After they melt, I gently remove the case and set it aside for to cool down to room temp. I wait around 25 minutes or so. Give it 30 minutes if you're using metal since I don't know how long it'll take to fully cool back down and solidify. But once you remove it and set it aside it should already be safe from detonation since it is already cooling down the moment you remove it. But take precaution anyway. ETN is much more sensitive when melted.


How do you seal the output end (the end with the ETN) from water? I use a similar process and have never had an issue. I seal the output end of my brass or copper tubes with compressed aluminium foil, so while it is not an aluminium tube the molten ETN is in contact with aluminium.

B(a)P - 17-11-2022 at 17:49

Quote: Originally posted by Hey Buddy  
Okay. That's it. I'm dragging out this thread. Going to study ETNs fascinating thermal idiosyncrasies in effort hammer down ETN DDT.

First step, working out foil phenomenon since it's an experience that pretty much every ETN user goes through.

First questions to understand are:

1) To what degree is foil ddt phenomenon permitted because of material interaction?
1a) Is foil ddt replicated on other metal foil surfaces that are non-Al?
1b) Is foil ddt replicated on non-foil Al surfaces, such as heated bar stock?
1c) Can foil ddt be replicated on any other thin foil-like surface other than metal? ie. ceramic/glass/plastics/kapton/metalloids/oxides

2) What are the circumstance under which ETN reliably DOES NOT ddt, where it seems to nearly always deflagrate and never detonate?

That's what to attack first: "where is the ETN ddt, where is it not."
Will be conducting some tests. Will post results.


I look forward to the results. I had read this thread previously and have also tried with ETN on aluminium foil and had it detonate, though not until it is way above its melting point. I suspect there is nothing special about aluminium other than its commonality as a foil and good heat transfer properties. I expect copper or silver foil would act the same.

Bert - 17-11-2022 at 18:41

Quote: Originally posted by B(a)P  
I look forward to the results. I had read this thread previously and have also tried with ETN on aluminium foil and had it detonate, though not until it is way above its melting point. I suspect there is nothing special about aluminium other than its commonality as a foil and good heat transfer properties. I expect copper or silver foil would act the same.


After observing explosions resulting from placing small quantities of such things as nitroglycerin or 70% NG ammonia gelignite on a STEEL sheet metal surface, then placing a low output propane burner underneath? I tend to agree that a slow cook off without direct flame contact may cause such things to detonate that otherwise would just burn harmlessly if touched by the flame (or otherwise do very little).

The experiences of unlucky (and feet partially missing) soldiers who used a few grams of C4 pinched off a bar of demo explosive & ignited as a field expedient ration heater, then foolishly tried to "stomp out" whatever burning residue was left after their meal was sufficiently warm are instructive as well.

Supply a good bit of activation energy environmentally, don't be surprised when the pussycat turns into a hungry tiger.

[Edited on 11-18-2022 by Bert]

MineMan - 17-11-2022 at 22:56

I have even see. AN mixtures DDT. The trick is finding the right size and ratio of AL powder. Try this, ETN 60 parts, Al 3 micron 20 parts, potassium perchlorate 20 parts and hexamine 5 parts. Have a loose powder of 2 grams fully sealed in a metal tube. That might do it :)

Herr Haber - 18-11-2022 at 13:01

Quote: Originally posted by ManyInterests  
I want to know if using an aluminum tube for melt-casting ETN poses danger of detonation? I melt cast by putting the case in water heated to the melting point of ETN, which is around 65C.

I asked this question previously. I just want reconfirmation.


It is perfectly safe

https://www.sciencemadness.org/whisper/viewthread.php?tid=14...

Edit: Use boiling water. Not 65... It takes time to fully melt and the water temperatures drops. Press the ETN to increase its heat conductivity and melt speed. If your water container is small and your cast big add boiling water until it overflows. If looking down the tube you see a sinkhole and not a flat surface you didnt use enough hot water. There's no need to remove the tubes from the water while anything is hot or molten. Just come back later when the water is cold.

[Edited on 18-11-2022 by Herr Haber]

Herr Haber - 18-11-2022 at 13:31

Quote: Originally posted by Bert  


The experiences of unlucky (and feet partially missing) soldiers who used a few grams of C4 pinched off a bar of demo explosive & ignited as a field expedient ration heater, then foolishly tried to "stomp out" whatever burning residue was left after their meal was sufficiently warm are instructive as well.

[Edited on 11-18-2022 by Bert]


Never heard about that but heard that the soldiers quicky noticed breathing the fumes of burning C4 was not good for health.

ManyInterests - 18-11-2022 at 13:36

Quote: Originally posted by Hey Buddy  
Quote: Originally posted by ManyInterests  
Thanks for finding this thread Hey Buddy.

Since ETN is my (currently) my preferred booster energetic and all my attempts at melt-casting ETN were so far done in plastic pen bodies (which I learned aren't good enough), I will be doing melt-casting ETN in steel tubes and brass shell casings. I want to know if using an aluminum tube for melt-casting ETN poses danger of detonation? I melt cast by putting the case in water heated to the melting point of ETN, which is around 65C.

I asked this question previously. I just want reconfirmation.


If no one else has an answer, I can just test this for you. Will be in lab tonight, have Al 8mm casings and ETN and Al powder. I can melt a 50:50 Al/ETN mix and straight ETN both in aluminum 8mm casings?

edit: how do you melt the case in water? in end-closed aluminum cases directly submerged into water or casings inside a test tube in water?

[Edited on 17-11-2022 by Hey Buddy]



What I did was use a bic round stick pen body to fill in the ETN (1 gram) and then gently press it to compact all the powder and then place it in the hot water until it is all melted. I usually keep it in for 7 minutes. The fact that the pen body is transparent, you can monitor the melting quite closely and know when it is done. After that I gently remove it and I put it in a foam yoga block with holes drilled in it to let it rest until the ETN has fully cooled and solidified.

I haven't used a non-closed end tube yet. Though I did buy some stainless steel drinking draws and I did crimp and bend the other end. The tiny bit of exposed opening was then sealed with liquid electrical tape.

I will probably use those last, as I do have some very lengthy and voluminous cartridge cases with closed ends (the spent primer is blocking it) and I do have some 8x50mm stainless steel tubes that are already sealed on the other end. I can use those to make 0.5g ETN + 0.4g NHN caps, I got some 8x100ml steel tubes ordered and should be here within a month, that is as long as I need it to make a powerful detonator that should reliably detonate fully.

 Pages:  1