Sciencemadness Discussion Board

Homemade det cord

a nitrogen rich explosive - 1-5-2016 at 09:17

I have tried to make homemade det cord with thin, flexible plastic pipes and ETN. They aren't anywhere near practical enough. Therefore, would nitrocellulose string saturated with MEKP work as a det cord? It is possible that it would be too sensitive, but gelignite is very stable. Would this work?

XeonTheMGPony - 1-5-2016 at 09:25

No, be way too unsafe in handling.

If you plasticized the ETN with a high volatility solvent to allow good density of loading then allow to dry, will do a much better job.

greenlight - 1-5-2016 at 10:28

I agree, way too unsafe to handle than detcord should be.

I think using ETN or PETN with a larger percentage of binder and plasticizer like 20% would work better.
This could be rolled to a high density and pressed into clear plastic tubing in theory. Biggest problem would be keeping the cord flexible without forming cracks or gaps in the explosive filling.
Seems like commercial detcord uses pressed powder PETN without the binder or plasticizer according to quick google search and appears to have an outer casing of nylon-looking material... Either they do add something to stop cracks and cavities forming in the explosive or it is made and loaded in a special way.

OneEyedPyro - 1-5-2016 at 10:38

I think a plastic with a low melting point would be the easiest option, for example ETN/NG/NC.
It could be melted and drawn into the tubing with a vacuum.

PHILOU Zrealone - 1-5-2016 at 11:51

In principle by virtue of the colligative laws...
ETN-PETN mix should have a lower mp than ETN alone.

OneEyedPyro - 1-5-2016 at 12:05

Quote: Originally posted by PHILOU Zrealone  
In principle by virtue of the colligative laws...
ETN-PETN mix should have a lower mp than ETN alone.


Doesn't the addition of NG complicate that relationship though?
If NG/ETN has a lower melting point than NG/PETN would a PETN/ETN/NG mixture have an even lower melting point?


[Edited on 1-5-2016 by OneEyedPyro]

a nitrogen rich explosive - 1-5-2016 at 12:43

Drawing it in with a vacuum. I hadn't thought of that.

Detcord

MineMan - 1-5-2016 at 13:45

All,

Let me share a story with you. I was involved in loading a blast where we would tape 2x8" emulsion sticks to 200 grain detcord about every 2.5', and then loaded this into a horizontal borehole for a blast. The 200 grain detcored is warped in nylon, and then wrapped in a clear thick plastic for added durability and weather proofness. The blast went off, but some detonators did not, the result was several pieces of detcord cut and buried under rocks that were angular, and over a ton in weight. We were able to recover the unexploded detcord safely.

The point of this is that the commercial detcord did NOT detonate even being pinched between falling rocks that weigh more than a motorcycle. But I can get ETN to detonate my putting a small amount on a hammer, and letting another hammer fall onto it (with no force from my wrist) from eight inches, and it goes. Which seems to be more shock sensitive than other experiments I remember...

Please don't expect ETN detcord to be that durable and that safe...even if you do find a great way to load it into cord. Anyways, my best thought so far is the nylon sheath from paracord... or of course get a license....

a nitrogen rich explosive - 1-5-2016 at 13:46

By get a license, what do you mean? I have an EPP license for explosives precursors and poisons. Nylon sheath from paracord is a good idea.

MineMan - 1-5-2016 at 14:01

What I meant is that commercial detcord is amazing in durability, low sensitivity, and the price point is not bad. It just does not make much sense in my opinion to make it.. although experimentation can provide some fun and learning.

I recall 200 grain detcord being sold for about $1 per foot, and that was a specialty item, I imagine that the standard 17 or 25 grain would be very affordable.

PHILOU Zrealone - 2-5-2016 at 12:15

Quote: Originally posted by OneEyedPyro  
Quote: Originally posted by PHILOU Zrealone  
In principle by virtue of the colligative laws...
ETN-PETN mix should have a lower mp than ETN alone.


Doesn't the addition of NG complicate that relationship though?
If NG/ETN has a lower melting point than NG/PETN would a PETN/ETN/NG mixture have an even lower melting point?


[Edited on 1-5-2016 by OneEyedPyro]

Yes tripple compound eutectic

James Ikanov - 20-5-2016 at 14:44

I have a question somewhat more in line with the initial post of this thread.

Assuming I could make a few thin sheets of nitrocellulose soaked with MEKP, then seal it all up in some variety of epoxy or some other method of holding the MEKP in, would it make viable "sheet" charges? I'm not sure how thick they'd have to be or how stiff they'd come out, but it seems like an interesting premise, to me at least. The idea of explosive duct tape (a wide strip, a layer or two of sheeting, and another layer of scotch tape or something) gives me a good chuckle.

I'm concerned it would have to be rather thick to pack any meaningful wallop, or worse, have a lot of power but be so dangerous to handle that flexing it might cause it to go off.

XeonTheMGPony - 20-5-2016 at 17:35

Quote: Originally posted by James Ikanov  
I have a question somewhat more in line with the initial post of this thread.

Assuming I could make a few thin sheets of nitrocellulose soaked with MEKP, then seal it all up in some variety of epoxy or some other method of holding the MEKP in, would it make viable "sheet" charges? I'm not sure how thick they'd have to be or how stiff they'd come out, but it seems like an interesting premise, to me at least. The idea of explosive duct tape (a wide strip, a layer or two of sheeting, and another layer of scotch tape or something) gives me a good chuckle.

I'm concerned it would have to be rather thick to pack any meaningful wallop, or worse, have a lot of power but be so dangerous to handle that flexing it might cause it to go off.


You missed the part of it poisoning you! MEKP and TATP are cute novelties but for a functional reliable system are worthless.