Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  2
Author: Subject: What’s your opinion?
wessonsmith
Hazard to Others
***




Posts: 203
Registered: 15-2-2018
Location: elsewhere
Member Is Offline


[*] posted on 15-11-2019 at 04:50


Quote: Originally posted by Microtek  

Quote:

I am looking for maximum energy and explosive speed. By adding aluminum to this explosive compound, I want to see the explosion rate would increase or not


From this, it seems that he is looking for something that isn't necessarily thermobaric or plastic. It also seems that he is looking for high explosion energy and high "explosion rate" (which I would interpret as VOD).


If that is the case, then ETN/PETN is all you need. Adding anything extra will sacrifice the VOD or maximum detonation pressure.

Thermobaric compositions sacrifice VOD and maximum detonation pressure for a vacuum and SUSTAINED detonation pressure.
View user's profile View All Posts By User
wessonsmith
Hazard to Others
***




Posts: 203
Registered: 15-2-2018
Location: elsewhere
Member Is Offline


[*] posted on 15-11-2019 at 05:03


Quote: Originally posted by MineMan  

I appreciate your very detailed explanation. But combined effect explosives have both a thermobaric effect and a high gurney velocity. Only possible with an active binder.... In fact... the gurney energy can be higher then without the metal powder... that’s impressive!


I agree. PETN1933 had reached out to me in a PM to discuss thermobaric compositions, that's why I was talking about them. To be clear, using an active binder is desirable if the goal is to maximize the VOD/detonation pressure. If the goal is to maximize the thermobaric effect, vacuum/sustained blast wave, then excess fuel is a must. Using an active binder in a thermobaric composition would negate the maximum thermobaric effect by reducing the fuel density of the composition.
View user's profile View All Posts By User
Rocinante
Hazard to Others
***




Posts: 121
Registered: 13-11-2017
Member Is Offline

Mood: No Mood

[*] posted on 15-11-2019 at 08:25


If you are looking for maximum detonation pressure and velocity, just melt cast ETN. Mixing it with anything is a receipe for bubbles, once the molten mass cools, significantly reducing pressure/velocity. Also, those mixes would require pressing in molten state, which is a no-no. Melt cast only 10 g at time.

If you are looking for a combined effects explosive, i.e. a melt cast with 15 % of Al that burn almost all the Al in just 7 expansions, use 15 % Al and some 30 % PETN + 55 % ETN, don't press and make sure that your explosives are pure (double recrystalization). Don't press it in molten state, don't agitate it. Sure, you'll reach lower VoD but being safe is more important. 1.5 density is OK, the pressure at that density is still high enough to crack those Al particles to burn rapidly at the sub-milisecond scale.

If you are looking at a thermobaric, just melt cast your ETN and surround it with a thin film of 30 % of Al, i.e. 60 g ETN and 30 g Al (smaller TBX charges don't rly work well due to rapid cooling of the cloud). Sure, some lower performance than a direct melt cast but much safer.

Melt cast the stuff in sillicone rubber, use a big bucket of hot water and be in different room after you pour in the water, just to be safe. Also, you should melt cast the combined effecrs explosive in 5 - 10 g batches - just to stop it from serious DDT if anything goes bad.

If you are looking for a cheap FAE bang, make a foil housing 80×80 cm wide and 50 cm high, use a plate and pour in 45 ml of Et2O, let it evaporate and detonate it via en electrical 3 g+ ETN blasting cap placed at the outside of the foil (total ETN mass, like 1 g in blasting cap and 2 g of ETN in booster).


[Edited on 15-11-2019 by Rocinante]
View user's profile View All Posts By User
MineMan
International Hazard
*****




Posts: 1012
Registered: 29-3-2015
Member Is Offline

Mood: No Mood

[*] posted on 15-11-2019 at 08:35


Quote: Originally posted by Rocinante  
If you are looking for maximum detonation pressure and velocity, just melt cast ETN. Mixing it with anything is a receipe for bubbles, once the molten mass cools, significantly reducing pressure/velocity. Also, those mixes would require pressing in molten state, which is a no-no. Melt cast only 10 g at time.

If you are looking for a combined effects explosive, i.e. a melt cast with 15 % of Al that burn almost all the Al in just 7 expansions, use 15 % Al and some 30 % PETN + 55 % ETN, don't press and make sure that your explosives are pure (double recrystalization). Don't press it in molten state, don't agitate it. Sure, you'll reach lower VoD but being safe is more important. 1.5 density is OK, the pressure at that density is still high enough to crack those Al particles to burn rapidly at the sub-milisecond scale.

If you are looking at a thermobaric, just melt cast your ETN and surround it with a thin flame of 30 % of Al, i.e. 60 g ETN and 30 g Al (smaller TBX charges don't rly work well due to rapid cooling of the cloud). Sure, some lower performance than a direct melt cast but much safer.

Melt cast the stuff in sillicone rubber, use a big bucket of hot water and be in different room after you pour in the water, just to be safe. Also, you should melt cast the combined effecrs explosive in 5 - 10 g batches - just to stop it from serious DDT if anything goes bad.

[Edited on 15-11-2019 by Rocinante]


Someone did their reading:D

He is correct, the aluminum can react by 7 expansions. :o

You sacrifice some VOD for higher gurney velocity.

I do have a question, is it safe to melt cast ETN with Al powder? Especially with how sensitive ETN is when molten?! That would make me very nervous.... but I scare easily. Still....
View user's profile View All Posts By User
Rocinante
Hazard to Others
***




Posts: 121
Registered: 13-11-2017
Member Is Offline

Mood: No Mood

[*] posted on 15-11-2019 at 08:44


Leftover acidity due to bad recrystalization or long storage (decomposition) can lead to a reaction with the aluminium, causing fire and possible DDT. It is pretty unlikely, though. Also, you should be in different room and casting 10 g should do no serious harm even an a case of full DDT. Just fill in the water (some 10l) and get back an hour later.

Yes, high Pdet explosive can crack those aluminium particles hard. Deformed, exposed Al will burn quickly. Have you read about this new coating https://www.nature.com/articles/s41598-018-26390-9 ?

[Edited on 15-11-2019 by Rocinante]

[Edited on 15-11-2019 by Rocinante]
View user's profile View All Posts By User
wessonsmith
Hazard to Others
***




Posts: 203
Registered: 15-2-2018
Location: elsewhere
Member Is Offline


[*] posted on 15-11-2019 at 12:18


Quote: Originally posted by MineMan  


I do have a question, is it safe to melt cast ETN with Al powder? Especially with how sensitive ETN is when molten?! That would make me very nervous.... but I scare easily. Still....


That's the real question right there. It is why I use HTPB and blend my ETN first, then add the metal powder after the ETN is thoroughly coated. Mixing ETN when it's melted with AL powder is just way too scary for me. One positive thing about risking mixing melted ETN and AL is that if you are making 100g or more and it does detonate, you sure as hell won't know it:)
View user's profile View All Posts By User
MineMan
International Hazard
*****




Posts: 1012
Registered: 29-3-2015
Member Is Offline

Mood: No Mood

[*] posted on 15-11-2019 at 23:50


Quote: Originally posted by Rocinante  
Leftover acidity due to bad recrystalization or long storage (decomposition) can lead to a reaction with the aluminium, causing fire and possible DDT. It is pretty unlikely, though. Also, you should be in different room and casting 10 g should do no serious harm even an a case of full DDT. Just fill in the water (some 10l) and get back an hour later.

Yes, high Pdet explosive can crack those aluminium particles hard. Deformed, exposed Al will burn quickly. Have you read about this new coating https://www.nature.com/articles/s41598-018-26390-9 ?

[Edited on 15-11-2019 by Rocinante]

[Edited on 15-11-2019 by Rocinante]


Great find!!!

Since everyone is in a spoon feeding mode... is this something we can do in the home lab?
View user's profile View All Posts By User
Petn1933
Hazard to Others
***




Posts: 106
Registered: 16-9-2019
Member Is Offline


[*] posted on 16-11-2019 at 01:13


I thank everyone who participated in the discussion. Good information has been exchanged on this subject which is certainly interesting to everyone.
Thank you :)
View user's profile View All Posts By User
MineMan
International Hazard
*****




Posts: 1012
Registered: 29-3-2015
Member Is Offline

Mood: No Mood

[*] posted on 16-11-2019 at 10:56


Quote: Originally posted by Rocinante  
Leftover acidity due to bad recrystalization or long storage (decomposition) can lead to a reaction with the aluminium, causing fire and possible DDT. It is pretty unlikely, though. Also, you should be in different room and casting 10 g should do no serious harm even an a case of full DDT. Just fill in the water (some 10l) and get back an hour later.

Yes, high Pdet explosive can crack those aluminium particles hard. Deformed, exposed Al will burn quickly. Have you read about this new coating https://www.nature.com/articles/s41598-018-26390-9 ?

[Edited on 15-11-2019 by Rocinante]

[Edited on 15-11-2019 by Rocinante]


Rocinante, they claim the Al increases TNT VOD to 9000m/s yet they are not bold enough to test this claim... I am suspicious. Anyone here want to give it a try?
View user's profile View All Posts By User
wessonsmith
Hazard to Others
***




Posts: 203
Registered: 15-2-2018
Location: elsewhere
Member Is Offline


[*] posted on 17-11-2019 at 06:38


Quote: Originally posted by MineMan  
Quote: Originally posted by Rocinante  
Leftover acidity due to bad recrystalization or long storage (decomposition) can lead to a reaction with the aluminium, causing fire and possible DDT. It is pretty unlikely, though. Also, you should be in different room and casting 10 g should do no serious harm even an a case of full DDT. Just fill in the water (some 10l) and get back an hour later.

Yes, high Pdet explosive can crack those aluminium particles hard. Deformed, exposed Al will burn quickly. Have you read about this new coating https://www.nature.com/articles/s41598-018-26390-9 ?

[Edited on 15-11-2019 by Rocinante]

[Edited on 15-11-2019 by Rocinante]


Rocinante, they claim the Al increases TNT VOD to 9000m/s yet they are not bold enough to test this claim... I am suspicious. Anyone here want to give it a try?


$280 plus shipping for 100g of 80nm Al powder, that's expensive.
View user's profile View All Posts By User
MineMan
International Hazard
*****




Posts: 1012
Registered: 29-3-2015
Member Is Offline

Mood: No Mood

[*] posted on 17-11-2019 at 15:13


Hmm. It can be obtained much cheaper from China... but, this could be done with 2 micron flake.

It seems the biggest issue is having a consistent AIH concentration.... paging Rosco!!!
View user's profile View All Posts By User
C6(NO2)5CH2CH(CH3)N(NO2)2
Harmless
*




Posts: 43
Registered: 4-4-2018
Member Is Offline

Mood: No Mood

[*] posted on 19-11-2019 at 16:58


Quote: Originally posted by Rocinante  
If you are looking for a cheap FAE bang, make a foil housing 80×80 cm wide and 50 cm high, use a plate and pour in 45 ml of Et2O, let it evaporate and detonate it via en electrical 3 g+ ETN blasting cap placed at the outside of the foil (total ETN mass, like 1 g in blasting cap and 2 g of ETN in booster).


[Edited on 15-11-2019 by Rocinante]


Have you tried this? I'm surprised 3gm of etn would initiate a gas cloud.

Regarding the nanoaluminum, dornier 335 A had a way to grind micron and submicron particles. Passivating those with iodate would be cool.




Put that in your pipe and smoke it!
View user's profile View All Posts By User
Rocinante
Hazard to Others
***




Posts: 121
Registered: 13-11-2017
Member Is Offline

Mood: No Mood

[*] posted on 20-11-2019 at 06:15


I would like to, in the future. So far I've had succes with only an e-match and 20 l of air with 2.8 g ml of diethyl ether (large water bottle). Loud. No way 3 g of ETN won't initiate a propper Et2O/air mixture.
View user's profile View All Posts By User
chemist1243
Hazard to Others
***




Posts: 170
Registered: 7-8-2019
Member Is Offline


[*] posted on 21-11-2019 at 12:35


hmmmmm. im not very sure about adding aluminum. i've heard ETN is a bit sensitive to metals, but, if you insist on adding any metal powders, id recommend you plasticize the mixture first. use something like paraffin and vasaline.
View user's profile View All Posts By User
LardmanAttack
Harmless
*




Posts: 37
Registered: 7-8-2019
Member Is Offline


[*] posted on 27-11-2019 at 21:02


I mean, you could just use NG or EGDN to dissolve the nitrocellulose, but I agree with everyone else that the NC won't do much.
View user's profile View All Posts By User
LardmanAttack
Harmless
*




Posts: 37
Registered: 7-8-2019
Member Is Offline


[*] posted on 27-11-2019 at 21:05


I wouldn't recommend binding with vaseline, in my experience it tends to completely desensitize ETN and other explosives to the point where you can't even set them off with a blasting cap easily. I would try to use liquid rubber or silicone.

[Edited on 28-11-2019 by LardmanAttack]
View user's profile View All Posts By User
 Pages:  1  2

  Go To Top