Sciencemadness Discussion Board

Help: Can ETN/PETN 4:6 be poured safely in a vacuum vibration environment?

PLSHY - 23-9-2023 at 02:51

I am planning to cast the shaped charge using an etn/petn 4:6 ratio which may come into contact with copper and mild steel when melted, as molten etn is notoriously sensitive so I would like to know if there is any danger when casting using this ratio ? If it was dangerous, I would eliminate the vacuum shock step and adjust the ratio to 1:1. I would add one percent diphenylamine as a stabilizer. Of course, the temperature throughout the process will not exceed 80 degrees, and an intelligent temperature-controlled water bath is used to adjust it. Please judge whether there are any dangers in this process? Because the amount of pouring is large (200~350gr), I want to avoid any risks. Or do you have any recommendations for pouring charges that are more suitable for energy gathering and safer? Thank you very much for your answer!

PLSHY - 23-9-2023 at 03:05

I have tried dozens of etn pours and several etn/petn pours before, but I have never touched metal when melting, and I have never tried vacuum vibration pouring, so I am very worried.

Metacelsus - 23-9-2023 at 04:08

That sounds rather dangerous to me (especially the vibration). If you want to avoid risk you could make a machine to do it automatically, and retreat to a safe distance.

OneEyedPyro - 23-9-2023 at 09:54

Quote: Originally posted by PLSHY  
I have tried dozens of etn pours and several etn/petn pours before, but I have never touched metal when melting, and I have never tried vacuum vibration pouring, so I am very worried.

The concept of 300 grams of very powerful high explosives detonating accidentally certainly should terrify you. I'd never physically manipulate that much molten ETN unless my life depended on it.

If you insist on it, I'd do as Metacelsus said and figure out a way to maintain a safe distance. If your container or anything around it will produce fragmentation ensure it's well shielded and not a danger to yourself or others if it does detonate.
Rather than pour it you could heat it in the container you intend to detonate it in.

Let us know before you try it so we can start a 'death after detonation' thread just in case something goes wrong and we never hear back from you. :P

[Edited on 23-9-2023 by OneEyedPyro]

PLSHY - 23-9-2023 at 19:29

Quote: Originally posted by OneEyedPyro  
Quote: Originally posted by PLSHY  
I have tried dozens of etn pours and several etn/petn pours before, but I have never touched metal when melting, and I have never tried vacuum vibration pouring, so I am very worried.

The concept of 300 grams of very powerful high explosives detonating accidentally certainly should terrify you. I'd never physically manipulate that much molten ETN unless my life depended on it.

If you insist on it, I'd do as Metacelsus said and figure out a way to maintain a safe distance. If your container or anything around it will produce fragmentation ensure it's well shielded and not a danger to yourself or others if it does detonate.
Rather than pour it you could heat it in the container you intend to detonate it in.

Let us know before you try it so we can start a 'death after detonation' thread just in case something goes wrong and we never hear back from you. :P

[Edited on 23-9-2023 by OneEyedPyro]
What you said does make sense, maybe I can pour it in multiple times (10 grams at a time) or give up this plan altogether, but the joke you made at the end made me a little uncomfortable, but thank you for your answer, I may use tnt cast instead of etn or simply use egdn mixed with petn (but then I can't use partitions)

[Edited on 24-9-2023 by PLSHY]

EF2000 - 25-9-2023 at 02:34

Does your mold conduct heat well? If yes, you can skip the pouring step and associated danger. Just fill mold with your mixture in powder form, then heat it up to melt. While staying at the safe distance.
Of course, homogenicity of resulting explosive will suffer (though it can be compensated with vibration, right?). But accidental detonation of ~500 g of TNTeq is too unpleasant way to join the host of heroes in Valhalla, visit Shangri-La and be reincarnated as unstoppable goddess of explosions in some video game world.
I'd rather choose non-homogenous melt cast on that side than ideal cast and ticket to other side.

[Edited on 25-9-2023 by EF2000]

ManyInterests - 25-9-2023 at 08:21

The most molten ETN I ever put was around 1g. And I did do it in a steel blasting cap as the main charge to a detonator. I wasn't aware that molten ETN became super sensitive in mild steel. Good thing I handled it with the care it deserved. But amount of melt-cast anything is... really powerful. Like 250/300g going off is like a bundle of grenades exploding all at once. Others have mentioned life after detonation, but here there will be no life after that.

I am curious as to what you wish to do with the shaped charge? Like legitimately so. That is also quite a lot of energetic material. I made a few hundred grams of stuff myself, but I never intended to make it into a charge. Even if I set it off in the middle of nowhere it will still be extremely loud and I highly doubt that people wouldn't hear it for kilometers around.
Quote:
Does your mold conduct heat well? If yes, you can skip the pouring step and associated danger. Just fill mold with your mixture in powder form, then heat it up to melt. While staying at the safe distance.



I do concur this for safety. Melt-cast ETN is no joke. I only melt-casted my stuff within the container (and again, not more than 1 or 1.2g) When I did it, I immersed my blasting cap in a hot water bath no more than 70C for 7 minutes before VERY carefully removing it and putting it in a foam block that I made a hole in specifically for holding detonators in place.

so hypothetically, if I had a cardboard tube (sealed on end with epoxy and covered in aluminum foil to protect from water) immersed the same way, would that safely allow a few hundred grams of ETN to be melt cast at once? I'm just curious here. I did end up accidentally melt-casting a few dozen grams in hot water when I was trying to rewash my ETN. Nothing happened, but that was a scary moment.

dettoo456 - 25-9-2023 at 11:02

I’d first mix the EM with wax just as a handling precaution (it won’t affect the performance too much anyways), then maybe try to make a copy of the shaped charge liner out of something like HDPE and then cast the EM in/onto that. You’d need to find a suitable mold release to pull the ETN puck off, then you can just plunk it onto the actual metal liner face. Also though, for stability’s sake, maybe try to coat the metal (Cu or steel) with a spray coat or non-reactive lacquer to prevent the ETN from metal contact under storage conditions. I don’t know if it’d be a big issue but PETN does degrade in the presence of Fe so you could run into similar issues with Cu and steel.

PLSHY - 25-9-2023 at 20:34

Quote: Originally posted by EF2000  
Does your mold conduct heat well? If yes, you can skip the pouring step and associated danger. Just fill mold with your mixture in powder form, then heat it up to melt. While staying at the safe distance.
Of course, homogenicity of resulting explosive will suffer (though it can be compensated with vibration, right?). But accidental detonation of ~500 g of TNTeq is too unpleasant way to join the host of heroes in Valhalla, visit Shangri-La and be reincarnated as unstoppable goddess of explosions in some video game world.
I'd rather choose non-homogenous melt cast on that side than ideal cast and ticket to other side.

[Edited on 25-9-2023 by EF2000]
It's a nice method, maybe I could just put it in scalding hot water and leave so I don't have the risk of stirring it, but there's a good chance it could blow up my apartment if it starts accidentally, so I thought I'd add A part of DNT or TNT reduces the sensitivity. I found that both substances can be miscible with etn in a certain proportion and lower the melting point (40 degrees Celsius). This may reduce the performance to a certain extent, but it is still enough. This is a good Method?

PLSHY - 25-9-2023 at 20:37

Quote: Originally posted by ManyInterests  
The most molten ETN I ever put was around 1g. And I did do it in a steel blasting cap as the main charge to a detonator. I wasn't aware that molten ETN became super sensitive in mild steel. Good thing I handled it with the care it deserved. But amount of melt-cast anything is... really powerful. Like 250/300g going off is like a bundle of grenades exploding all at once. Others have mentioned life after detonation, but here there will be no life after that.

I am curious as to what you wish to do with the shaped charge? Like legitimately so. That is also quite a lot of energetic material. I made a few hundred grams of stuff myself, but I never intended to make it into a charge. Even if I set it off in the middle of nowhere it will still be extremely loud and I highly doubt that people wouldn't hear it for kilometers around.

Quote:
Does your mold conduct heat well? If yes, you can skip the pouring step and associated danger. Just fill mold with your mixture in powder form, then heat it up to melt. While staying at the safe distance.



I do concur this for safety. Melt-cast ETN is no joke. I only melt-casted my stuff within the container (and again, not more than 1 or 1.2g) When I did it, I immersed my blasting cap in a hot water bath no more than 70C for 7 minutes before VERY carefully removing it and putting it in a foam block that I made a hole in specifically for holding detonators in place.

so hypothetically, if I had a cardboard tube (sealed on end with epoxy and covered in aluminum foil to protect from water) immersed the same way, would that safely allow a few hundred grams of ETN to be melt cast at once? I'm just curious here. I did end up accidentally melt-casting a few dozen grams in hot water when I was trying to rewash my ETN. Nothing happened, but that was a scary moment.
I'm going to use it to penetrate steel columns, which is apparently legal in our country, and I need to design a low-cost, high-power perforating charge.

B541A798-58CF-4D4F-9978-A677CCF5BA13.jpeg - 1.2MB527A7B72-2484-43B9-843F-F640942120F7.jpeg - 2.5MB

Microtek - 25-9-2023 at 23:38
Quote:

blow up my apartment


Please don't work with that amount of very sensitive HE in an appartment. You will definitely be endangering the people living around you.

EF2000 - 26-9-2023 at 00:35

Really now, don't do it in apartment, in house or even in garage. It can do a lot of damage, like collapsing ceiling or rupturing gas tubes.

If I would be doing such project, I'll go to the steppe, dig a hole and heat the mold in water bath with something like portable stove (maybe there are electric ones, working from something like car battery, didn't check) or low-temperature flame (hexamine fuel tablets).

About adding TNT, pentolite was used for HEAT charges and small explosive shells (like HEFI for anti-air) with no issues. Penetration performance of old HEAT shells sounds puny today (~130 mm for 105 mm howitzer shell). But that's because they were rotating, not because pentolite is weak or something.

[Edited on 26-9-2023 by EF2000]

PLSHY - 26-9-2023 at 01:06

Of course I am not doing this in a building, but in a bungalow in the village with few people around...Thank you for your concern

Tsjerk - 26-9-2023 at 03:53

If you don't care about the absolute best performance, then why would you melt cast to begin with? Powdered PETN or ETN works just fine for shaped charges.
Quote: Originally posted by PLSHY  
but there's a good chance it could blow up my apartment if it starts accidentally


Quote: Originally posted by PLSHY  
Of course I am not doing this in a building, but in a bungalow in the village with few people around.


Right... And a bungalow is not a building and a few people are not people?

[Edited on 26-9-2023 by Tsjerk]

PLSHY - 26-9-2023 at 06:05

Quote: Originally posted by Tsjerk  
If you don't care about the absolute best performance, then why would you melt cast to begin with? Powdered PETN or ETN works just fine for shaped charges.



Quote: Originally posted by PLSHY  
but there's a good chance it could blow up my apartment if it starts accidentally


Quote: Originally posted by PLSHY  
Of course I am not doing this in a building, but in a bungalow in the village with few people around.


Right... And a bungalow is not a building and a few people are not people?

[Edited on 26-9-2023 by Tsjerk]
Only I can enter this house, and it has only one floor (about 70 square meters), so it is called a bungalow，and sparsely populated means that there are not many people living around it. This house is our old house, but I don't want anything to explode inside, so I asked the question "Can it be cast safely? Because the volume is large, I want to avoid any accidents and use pressed pbx is also a good method, but the density of the pressed grain is too low. Since the penetration depth of the homogenized target plate is directly proportional to the square of the explosion velocity, I want to increase the density as much as possible, so using tnt casting will also The effect is much better than simply suppressing it. I agree that adding a part of dnt is a compromise on sensitivity, but it does not mean that I don’t care about power at all.

[Edited on 26-9-2023 by PLSHY]

PLSHY - 26-9-2023 at 06:33

Forget about the house, I'm pretty sure I'm the only one who would be hurt if anything less than 1kg of tnt exploded inside (or the termites that live there). What I prefer is that there is no possibility of explosion, rather than reducing losses when there is a possibility of explosion, because I don’t want to be exposed to the risk of losing my life at any time. If you tell me that using melted ETN is likely to explode at any time, then I will give up this immediately plan! I am now considering adding a certain proportion of dnt or tnt to reduce the sensitivity or simply using tnt for casting. For safe casting, I added diphenylamine, used stainless steel for the casing, and tinned the copper shroud. In fact, the sensitivity of melted etn is very complicated. The sensitivity of liquid nitrate seems to be proportional to the viscosity (only for NG homologues, such as etn, egdn). I checked the relevant information and found that the drop weight sensitivity of methyl nitrate is 40 cm, ethylene glycol dinitrate increases to 20 cm, while nitroglycerin is 5 cm, melted etn is 1 cm +-0.6 cm. This is also almost directly proportional to their viscosity and inversely proportional to the difficulty of low-speed detonation. This seems to be related to the way they detonate: the bubbles in the liquid are subject to external impact, causing the bubbles to be sharply compressed, increasing a large amount of internal energy, and eventually causing the explosive to be detonated. I read in a book that the impact sensitivity of nitroglycerin with bubbles and without bubbles is about 20 times different. The viscosity of a liquid is also related to the number of bubbles contained within it.

PLSHY - 26-9-2023 at 06:46

Therefore, the high sensitivity of ETN does not come from itself, but from the bubbles trapped by its high viscosity, so the melted ETN that has been eliminated by vacuum should have a lower sensitivity. (We all know that semi-crystalline NG is the most sensitive due to the friction between the internal sensitive crystal and the liquid). Will petn and melted etn have such friction? After all, petn has a certain solubility in etn, so it is also very There may be crystallization, and petn will increase the viscosity and bubbles of melted etn, so it stands to reason that petn will increase the sensitivity of etn, but experiments tell us that petn will reduce the sensitivity of etn, which is really interesting. In addition, the impact sensitivity of NG with bubbles removed is twice as low as that of petn. This means that the sensitivity of melted etn without bubbles is likely to be more insensitive than that of unmelted etn! Has anyone had any experience or experience with this? I think I’d love to explore!

OneEyedPyro - 26-9-2023 at 10:08

Quote: Originally posted by PLSHY  
Therefore, the high sensitivity of ETN does not come from itself, but from the bubbles trapped by its high viscosity, so the melted ETN that has been eliminated by vacuum should have a lower sensitivity. (We all know that semi-crystalline NG is the most sensitive due to the friction between the internal sensitive crystal and the liquid). Will petn and melted etn have such friction? After all, petn has a certain solubility in etn, so it is also very There may be crystallization, and petn will increase the viscosity and bubbles of melted etn, so it stands to reason that petn will increase the sensitivity of etn, but experiments tell us that petn will reduce the sensitivity of etn, which is really interesting. In addition, the impact sensitivity of NG with bubbles removed is twice as low as that of petn. This means that the sensitivity of melted etn without bubbles is likely to be more insensitive than that of unmelted etn! Has anyone had any experience or experience with this? I think I’d love to explore!


It might be possible to use a solvent like acetone to create a hot saturated solution essentially making it unable to detonate while pouring then remotely pull a vacuum under vibration and heating allowing you to get back while the acetone evaporates and the ETN/PETN reaches its natural melting point.

This would obviously bring extremely flammable vapors into the equation possibly causing a fire leading to an accidental detonation. You'd at least be a safe distance away. Keeping air out of the system and eliminating all possible ignition sources nearby would be necessary.

Microtek - 26-9-2023 at 23:20
Quote:

Therefore, the high sensitivity of ETN does not come from itself, but from the bubbles trapped by its high viscosity


Correlation does not imply causation, meaning, this conclusion is a logical fallacy. It is entirely possible that the increased sensitivity of molten ETN is caused by the increased energy of the molecules (which will lower the required activation enrgy) rather than any trapped bubbles. This would make your assumption of increased safety from vacuum vibration false, which would lead to an increased risk of accident.

If your question is "is it safe to melt cast ETN" then the answer is a definite no. There are steps you can take to mitigate the consequences of accidental detonation, but with larger amounts of HE this becomes more difficult.

I don't know if any rigorous experiments with ETN/PETN sensitivity in the molten state have been done, though Roscoe seemed to have some experience with compositions along these lines.

[Edited on 27-9-2023 by Microtek]

PLSHY - 26-9-2023 at 23:53

Quote: Originally posted by Microtek  

Quote:

Therefore, the high sensitivity of ETN does not come from itself, but from the bubbles trapped by its high viscosity


Correlation does not imply causation, meaning, this conclusion is a logical fallacy. It is entirely possible that the increased sensitivity of molten ETN is caused by the increased energy of the molecules (which will lower the required activation enrgy) rather than any trapped bubbles. This would make your assumption of increased safety from vacuum vibration false, which would lead to an increased risk of accident.

If your question is "is it safe to melt cast ETN" then the answer is a definite no. There are steps you can take to mitigate the consequences of accidental detonation, but with larger amounts of HE this becomes more difficult.

I don't know if any rigorous experiments with ETN/PETN sensitivity in the molten state have been done, though Roscoe seemed to have some experience with compositions along these lines.

[Edited on 27-9-2023 by Microtek]
I am not completely sure about this conclusion, but it is very possible based on speculation. In C.H. Johnson's book "Detonation of Explosives", the detonation process of liquid nitrate explosives and the relationship between bubbles and sensitivity are explained in great detail. Of course, I may be wrong. The low activation energy caused by high temperature may also be the reason for the high sensitivity of melting etn.

PLSHY - 27-9-2023 at 00:02

However, there is another point worthy of our attention, that is, the sensitivity changes drastically from solid to liquid. The sensitivity of almost all explosive liquids will be much higher than that of solids. Even TMETN, which is famous for its insensitivity, or PETN, which is famous for its stability, are still mainstream. This is true for TNT. This is obtained through experiments. However, the small increase in internal energy brought by the slowly rising temperature cannot well explain the drastic change in sensitivity from solid to liquid. Therefore, CH Johnson proposed a special detonation method for liquid explosives. way (as shown in the figure). This is most likely a common property of all explosives with two phases. Note that it is all explosives with two phases, not just liquid or nitrate explosives.

8DE9FFBD-5909-4E92-96E1-C100E7C91028.png - 1.1MB

PLSHY - 27-9-2023 at 00:13

The sensitivity of the NG with bubbles removed is nearly 20 times lower than that of the normal tested NG! This speaks volumes! And there is a good way to remove bubbles in liquid explosives, which is to replace the bubbles with water and melt the explosives with water to obtain molten etn without bubbles.

Microtek - 27-9-2023 at 02:42

Nevertheless, making assumptions regarding sensitive high explosives in large amounts is a good way to not grow old. I urge you to err on the side of caution, and assume that molten, vacuum treated ETN is as sensitive as the non-vacuumed version. That way, you won't be killed if the assumption turns out to be wrong.

OneEyedPyro - 27-9-2023 at 03:38

Quote: Originally posted by PLSHY  
The sensitivity of the NG with bubbles removed is nearly 20 times lower than that of the normal tested NG! This speaks volumes! And there is a good way to remove bubbles in liquid explosives, which is to replace the bubbles with water and melt the explosives with water to obtain molten etn without bubbles.


Regardless of air pockets the ETN will be in a more shock sensitive state as temperatures go up. At room temperature it's already considered to have near primary levels of sensitivity.

PLSHY - 27-9-2023 at 05:09

I would experiment with small ones (like 5 grams) before larger experiments, and take any explosives seriously!

Microtek - 27-9-2023 at 08:10

It would be better if you did sensitivity tests on molten ETN in even smaller amounts (less than 1 g). So melt such a small amount and hit it in a measurable manner and compare to solid ETN and PETN. Then do the vacuum treated molten ETN to see if there is any significant difference. Remember to do at LEAST five repetitions.

PLSHY - 28-9-2023 at 03:36

I found that all current etn-related accidents are caused by temperature, not mechanical impact. This means that if no heat source is used during the pouring process, most accidents can be avoided! Finally, I decided to test the impact sensitivity of melted etn and its safety under vacuum. If the melted etn with bubbles removed can achieve a lower impact sensitivity than PVA-LA, I will use 1:1 etn/petn in water The shaped charge warhead is cast below, divided into 200 grams and 100 grams. I believe this will achieve good results. It is expected to launch this warhead in December, and relevant information will be posted on the shaped charge thread at that time.

MineMan - 3-10-2023 at 00:40

This is dumb.

MineMan - 3-10-2023 at 00:41

Accident in the making. Accept
Things
As they are

PLSHY - 5-10-2023 at 10:28

Quote: Originally posted by MineMan  
This is dumb.
Oh my god, isn't that enough? Is it also foolish to add proof of theory to reality testing? If you want to refute me, you should use theory to prove why my theory is wrong, or give a few examples of accidental melting etn caused by mechanical impact! Instead of just saying "You're so stupid" and walking away, it makes me so angry! I suspect you didn't watch the entire discussion and just saw the outcome: "I'm going to use a lot of melt etn"

[Edited on 5-10-2023 by PLSHY]

Microtek - 5-10-2023 at 22:34

In engineering courses on risk assessment and management you learn that the burden of proof must be the other way round. You want to do an activity such as melt casting a large amount of sensitive HE. We can identify several possible outcomes, at least one of which is catastrophic (the accidental detonation of the HE). If we assume that this outcome is likely, we can conduct the process with adequate precautions (remote operation, large safety distance and so on), and if the assumption turns out to be wrong, we will only have wasted the effort that went into our precautionary measures.
Conversely, if we assume that the catastrophic outcome is UNlikely, and therefore conduct the procedure without safety measures, then if the assumption turns out to be wrong we will lose life or limb.
So, it is a question of what you risk losing. You must understand that extrapolating from observations made in a different context means that you assume that the same mechanism apply in this context. And also that the absence of reports about mechanically induced accidents while melt casting ETN may be explained precisely by people dying when they try it.

UndermineBriarEverglade - 27-9-2024 at 06:34

PLSHY, did you ever carry out this experiment? It seems like a bad idea to pour molten ETN, or to vibrate it. Its sensitivity is dramatically higher when melted. For instance Lease et al. 2018 found that molten ETN could be detonated by 2.5kg dropped from 1cm, an impact of 0.25J. That was close to the low end of what their apparatus could test.

But I have also been thinking of melting ETN in a vacuum to extract bubbles.

PLSHY - 30-10-2024 at 08:57

Thanks to the forum for reminding me, I didn't do this experiment in the end. A friend of mine did this experiment, he soaked it in hot water and then ran away quickly. In the end, there was no accident, but the experiment failed and the melted etn leaked out. After that, we did not conduct related experiments again, but turned to looking for more convenient, cheap and safe mixed explosives. Looking back, this was indeed dangerous and irresponsible behavior. If anyone has ever been angered by me, I sincerely apologize to you.

PLSHY - 30-10-2024 at 09:05

We tried some other explosives, such as tmptn and dipehn. But they all failed, and we never found an excellent casting explosive like etn. tmptn turns into a sticky paste after nitration (and is difficult to solidify). Dipehn produces holes when casting. We also tried many ways to improve their shortcomings, but ultimately failed. The process of testing them is very interesting, if anyone wants to hear it, I can send it out

PLSHY - 30-10-2024 at 09:06

We tried some other explosives, such as tmptn and dipehn. But they all failed, and we never found an excellent casting explosive like etn. tmptn turns into a sticky paste after nitration (and is difficult to solidify). Dipehn produces holes when casting. We also tried many ways to improve their shortcomings, but ultimately failed. The process of testing them is very interesting, if anyone wants to hear it, I can send it out