Sciencemadness Discussion Board

Stupid Questions

VSEPR_VOID - 11-4-2018 at 19:56

Even after checking the SM library, (specifically The Chemistry of Powders and Explosives) I have a few questions regarding primers, RDX, and PETN that I imagine will be answered in a single response, from a much more knowledgeable amateur than myself. I appreciate the information.

What primers are traditionally used to detonate (is that the correct terminology?) RDX?

Is there a complete list of primers, what they are used for commercially/militarily, and their properties?

How do blasting caps incorporating PETN function?

greenlight - 11-4-2018 at 20:32

1. The typical primer/blasting cap if thats what you mean is an RDX base charge with lead azide primary on top. Lead styphnate is usually mixed with the lead azide to increase flame sensitivity.

There is a large amount of research going on to replace the lead azide due to contamination of training grounds and the overall toxicity of heavy metal salts to humans.

2. I guess you would be looking for this. Its my go to book for info on any primaries: https://books.google.com.au/books/about/Primary_Explosives.h...

3. I use PETN in my caps because it can be made without having to vac distill 99% nitric and it works just as well. I have pressed caps with RDX too and have noticed no difference in initiatory performance.

markx - 11-4-2018 at 22:35

In theory any secondary can be initiated by any primary that delivers enough "momentum" to handle the task and is chemically compatible with the system (does not cause detrimental reactions with other components).

On a side note I must say that nitramines tend to be inherently more passive towards intitation compared to nitric esters. Also they tend to have larger critical diameter compared to esters. These properties are also dependant on crystal size: coarser material will be more difficult to initiate. But nitramines are chemically more stable. So there will be pros and cons to consider...

XeonTheMGPony - 12-4-2018 at 04:12

last fucking try to upload shit 30 minutes of bullshit!

Attachment: Critical diameter of fulminated mercury and Pb Azide Naval report.pdf (3.7MB)
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Attachment: Efficiency of detonators.pdf (759kB)
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Attachment: Detonator develoupment and design.pdf (1.7MB)
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Attachment: explosives-and-detonators.pdf (4.9MB)
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This has taken fing 1.5H wtf!

Attachment: Initial_priming_substances_for_high_expl.pdf (1.5MB)
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[Edited on 12-4-2018 by XeonTheMGPony]

Attachment: Initiation and propigation in primaries.pdf (2.6MB)
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[Edited on 12-4-2018 by XeonTheMGPony]

Attachment: Si-CaSO4 delay eliment analysis.pdf (6.3MB)
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Attachment: Calcioum sulfate silicon time delay.pdf (410kB)
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Attachment: 2015 Tichapondwa Si-CaSO4.pdf (521kB)
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VSEPR_VOID - 12-4-2018 at 10:37

So if PETN can be used in caps gor RDX why would the millitary bother with lead salts?

How does one safely make PETN detonate rather than burn? I have only seen videos of the later.

XeonTheMGPony - 12-4-2018 at 12:10

Spark gap detonates use PETN directly, but they modify the crystal structure for the first stage.

Other wise it is a sequence LS, LA, RDX or PETN or a mix of both

(LS = Lead styphlanate, LA= Lead Azide)

VSEPR_VOID - 12-4-2018 at 13:07

Great information! How is the crystal structure modified and what voltage/amperage is used?

yobbo II - 12-4-2018 at 14:02


https://www.sciencemadness.org/whisper/viewthread.php?tid=23...

https://www.sciencemadness.org/whisper/files.php?pid=400976&...



VSEPR_VOID - 12-4-2018 at 17:22

Thank you, They are good threads