Sciencemadness Discussion Board

For those curios about cast ETN

Motherload - 3-7-2014 at 20:48

What was used to set it off ?
I am still not comfortable with the idea of heating ETN @ 60*C+.
Did you use hot water ?

goldenoranges - 5-7-2014 at 10:21

I have heard about people heating it up in hot water before, but I personally never have or will try it, unless I can find a way to do it completely safe.

NeonPulse - 5-7-2014 at 15:08

I have cast ETN a couple of times and it was done by loading the container you want to use and placing into a hot water bath at around 70℃ and leaving it to melt remotely, checking on it to ensure it all melted and replacing hot water as needed. I have only done it in 5g or less amounts though. It is not recommend to agitate this substance while melted as it is said to be very sensitive and may detonate. I haven't actually heard of this happening but I won't test my luck to find out... To detonate the cast use a cap with a little loose packed ETN and you should be all good

Turner - 5-7-2014 at 16:18

I pressed the ETN into a mold, which was a plastic cylinder and placed a detonator casing in the center. I put this in RT water, taped in place. I turned the heat on and left, came back an hour later, the water was boiling, turned the heat off and left again. Came back once it hardened, let it cool all the way, and removed it.

The action piece:




Originally I wanted to test a myth that cast ETN is very insensitive, needing 5-10g of pressed ETN to fire, but I decided to stick 8 grams of ETN plastique around the cap.




[Edited on 6-7-2014 by Turner]

[Edited on 9-7-2014 by Bert]

NeonPulse - 5-7-2014 at 17:02

The 8g booster may be a little too much and will overshadow the power of the cast. How big was the cast piece? Seems to have a yellowish tint to it, my castings were snow white. I did recrystallize it twice though.

Turner - 5-7-2014 at 17:12

That is epoxy because I accidentally broke it.

It was surprisingly small in volume for it's mass.

Dornier 335A - 5-7-2014 at 23:47

Could you measure its density? That's something many sources have very different values for. Wikipedia says 1.6 g/cm3 but a paper I linked to in another thread a while ago stated that the crystal density is 1.72 g/cm3.

hissingnoise - 6-7-2014 at 01:19

Quote:
That is epoxy because I accidentally broke it.

Stay lucky . . . ?

papaya - 6-7-2014 at 01:38

most interestingly you don't want to show what happened to the cast iron afterwards?

Turner - 6-7-2014 at 18:21

Quote: Originally posted by Dornier 335A  
Could you measure its density? That's something many sources have very different values for. Wikipedia says 1.6 g/cm3 but a paper I linked to in another thread a while ago stated that the crystal density is 1.72 g/cm3.



I did not measure the density. I too have seen different specs for ETN's VOD and crystal density. I am almost certain that ETN's VOD is right around 8000m/s at max density. I know there exists an accurate report of it's density and VOD but I am having a hard time finding it.

...Dany where you at?

Dornier 335A - 6-7-2014 at 23:07

Don't worry Turner, I attached the report below.

Attachment: Characterization and Analysis of Tetranitrate Esters.pdf (806kB)
This file has been downloaded 772 times

Turner - 7-7-2014 at 12:53

I have little doubt that a majority of the cast was very close to that number 1.72g/cc.

As for what it did to the metal; I am going to hold off a few weeks then I'll post the vid for those curious.

[Edited on 7-7-2014 by Turner]

Metacelsus - 7-7-2014 at 19:14

Tonight, I did a test of the sensitivity of cast ETN. 18g ETN was melted in a beaker in hot (70-80 C) water, and poured into the mold. The molten ETN took up more than 10 mL, but less than 15. The ETN was successfully initiated by 200 mg lead azide.

Turner - 7-7-2014 at 20:02

"poured" ETN into the mold!!??!

Maybe the molten material isn't as sensitive as it was thought to be.

That is surprising that it detonated by 200mg of LA, but valuable information none the less that my test couldn't give. Cast ETN will never work in a blasting cap though, even heavily pressed ETN has failed in a few of my detonators.

I would comfortably cast ETN again using the same method I used, although not sure if I would pour the molten ETN into a mold.

It is the best choice IMO for an amateur to achieve an explosive velocity in the ~8000m/s range.



[Edited on 8-7-2014 by Turner]

underground - 7-7-2014 at 20:49

I have achieve high density of etn by adding a little bit on NM. i may would be more than 1.70 g/cc

Metacelsus - 8-7-2014 at 06:50

I assumed molten ETN was about as sensitive as nitroglycerin, which can be safely poured. I might have been wrong, however (and am just lucky to still have my hands). How sensitive is molten ETN?

Turner - 8-7-2014 at 07:36

I figured frozen nitroglycerin is rather insensitive, compared to the "molten" state, since nitro and ETN are chemically similar, and ETN is fairly sensitive in it's "frozen" state, that it would be even more sensitive in it's molten state. This could be incorrect though.

All accidents I have seen with ETN were the result of rapid heating causing it to detonate (glass containing ETN and using flame.) or hot plate.


How did you know it detonated? (Ya I know, sound) but any witness plate? Video?


[Edited on 8-7-2014 by Turner]

VladimirLem - 8-7-2014 at 08:28

Quote: Originally posted by underground  
I have achieve high density of etn by adding a little bit on NM. i may would be more than 1.70 g/cc


so, is it (ETN) soluble into NM (like PETN to NG) or is it more like ANNM (insoluble)....it soulds like the first one that could be very interesting (ETN positive OB, NM negative OB and so on)

underground - 8-7-2014 at 08:41

Quote: Originally posted by VladimirLem  
Quote: Originally posted by underground  
I have achieve high density of etn by adding a little bit on NM. i may would be more than 1.70 g/cc


so, is it (ETN) soluble into NM (like PETN to NG) or is it more like ANNM (insoluble)....it soulds like the first one that could be very interesting (ETN positive OB, NM negative OB and so on)


Just found the corect ratio of etn/nm to be perfect OB and try to mix them into a plastic container untill all of the etn will be wet from the mn. Really powerfull, this is what i use for my boosters

Bert - 8-7-2014 at 11:41

I have personally seen 500mg of cast ETN detonated repeatedly (over 30 trials, no failures) by 35mg of Lead azo clathrate hand pressed on top and fuse ignited in a 6.5mm OD copper capsule- with no re-enforcing cap, flash igniter or other special ignition techniques used.

I would NOT choose to hand pour the molten material.

This thread is likely going to get merged into the short question/quick answer thread along with several other ETN threads. Motherload: contact me if you have a particular desire as to which, or the desire to edit OP into a guideline compliant thread.

Metacelsus - 8-7-2014 at 11:47

Quote: Originally posted by Turner  

How did you know it detonated? (Ya I know, sound) but any witness plate? Video?


Sound, of course. I also used a witness plate (1/8 inch steel, 6 inches by 6 inches), but I couldn't find it afterwards. It's the kind of plate I usually use for smaller tests, and I didn't have anything bigger.

Where did you get that manhole cover?

Texium - 8-7-2014 at 12:14

It appears that the manhole is still in the ground and that just happens to be where it is located. (You can see the rim of the manhole around the cover)
I wonder what the city will think about that when they find it like that!

Metacelsus - 8-7-2014 at 13:30

Damaging government property just gives the police one more reason to get mad and arrest you (and one more thing they can charge you with). Don't provoke them!

[Edited on 8-7-2014 by Cheddite Cheese]

goldenoranges - 12-8-2014 at 17:29

This might help, but I detonated about 5g cast ETN with about 200mg powdered ETN mixed with 100mg of fine aluminum powder. It seems that when ETN reaches its melting point and is in contact with aluminum, it detonates rather reliably. I haven't done it very many times, about 7, but they all reliably detonated. I used the powder mixture as a primary for the cast ETN, then used the cast ETN to detonate ANNMAL. I believe you could achieve the same result using electrical detonation, using nichrome wire instead of the fuse to heat the powder to the melting point, but I have not yet tested this. I would probably have to set up some capacitors to dump a bit of power into to get it to heat up quick.

Density

dangerous amateur - 15-8-2014 at 03:48

When i cast ETN, will it automatically have the optimal density and thus the best possible brisance?

Does it shrink or expand when it cools down?

I consider casting ETN into caps, just the last 200mg or so, because my tubes cannot support high loading pressures, and hand pressing only gives my about 1,3g/cm³

Dany - 15-8-2014 at 04:01

The concept of melting an explosive and let it cool to achieve high density is simple but not easy to achieve experimentally. Certainly you will get high density if you cast ETN but not necessarily the highest possible density because when you cool ETN (or any other explosive) the cooling process is faster at the edge of the charge than it's center. Because of this temperature gradient the edges will solidifies before the center part and there will be a density gradient in the final charge. Special apparatus are used in the industry to make homogenous cast charge and this by avoiding thermal gradient along the different charge layers. A phenomenon knows as piping is very known for TNT explosive when cooled in an amateur way. When a cylinder of TNT cool with thermal gradient the edge solidifies and shrinks leaving a void in the center of the charge. the final result is a solid cylinder with a hole along the charge (piping).

Dany.

dangerous amateur - 15-8-2014 at 05:33

And when I let the stuff cool down very slow?
I could put my caps in a large waterbath with 70°C, and let it cool down over an hour or so.