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FeedMe94
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My det casings are 6mm x 50mm. Today i detonated 0.8 PETN with 60mg SADS. The second test failed and a friend told me about critical diameter of PETN
which is 9mm. If thats true how did the first detonator went off ?
https://ibb.co/gJ18FnS
https://ibb.co/4ShDxLr
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Laboratory of Liptakov
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Whats the question? Critical diameter (minimal diameter of a rod that can sustain detonation propagation): 0.9 mm for PETN at 1 g/cm3, smaller for
higher densities (other value: 1.5 mm)
https://en.wikipedia.org/wiki/Pentaerythritol_tetranitrate
Development of primarily - secondary substances CHP (2015) Lithex (2022) Brightelite (2023) Nitrocelite (2024)
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FeedMe94
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Sorry but my English are not good. Critical diameter is the lowest diameter of the detonator case that will allow PETN to explode , right ? My case is
6mm and still detonated
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MineMan
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Your friend is wrong. Industrial detonators use PETN in 6mm!!! PETN works in detcord which is 2mm. You need more or a better primary.
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FeedMe94
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Quote: Originally posted by MineMan  |
Your friend is wrong. Industrial detonators use PETN in 6mm!!! PETN works in detcord which is 2mm. You need more or a better primary.
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I thought SADS was a good primary. At the moment i can only have TATP and SADS
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Rocinante
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just use more, at least 170 mg
be warned, tho... SA.DS does degrade if not well sealed and isolated (10 days+)
SA.DS will degrade from direct contact with PETN, esp. not recrystalzed... the remains of sulfuric acid will convert the surface of SA.DS....
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Laboratory of Liptakov
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SA.DS is best primary between classic materials. But is weak. Has 3460 m/s at best density. Is it not some great. Lead azide has 5200m/s. And
commerce filling is 300 mg. Therefore your det. device are no-reliable with 0,06 SA.DS. Thats clear... ...LL
Development of primarily - secondary substances CHP (2015) Lithex (2022) Brightelite (2023) Nitrocelite (2024)
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XeonTheMGPony
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| Quote: Originally posted by Laboratory of Liptakov | | SA.DS is best primary between classic materials. But is weak. Has 3460 m/s at best density. Is it not some great. Lead azide has 5200m/s. And
commerce filling is 300 mg. Therefore your det. device are no-reliable with 0,06 SA.DS. Thats clear......LL |
Commercial is an 80% Lead Azide and 20% Lead Styphnate
In a re-enforcing cap pressed it can be as low 100mg.
But for some one new with out much practical experience best never go below 300mg of primary till you develop some basic tooling.
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Laboratory of Liptakov
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My word, same opinion. On amateur field with amateur cavity is better always use 300 mg for any primary compound.
Development of primarily - secondary substances CHP (2015) Lithex (2022) Brightelite (2023) Nitrocelite (2024)
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MineMan
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Did you follow the correct procedure for SADS?! Preparation effects power. Mix 20 percent PP in. Should only need 50-100mg. Make sure you have 100mg
of loose PETN on top of your pressed PETN. SADS will do fine. Is your product white as snow? Because mine DDTs in under a mg.
Make sure you read the section in Primary Explosives.... synthesis temp is VERY important.
Also. Why not just make CHP or TACP with glycine??
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FeedMe94
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Is not pure white but detonates unconfined even at 1mg. Cannot make CHP or TACP cause i don't have AP
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Herr Haber
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300 mg ?!
When ETN / PETN is initiated by as low as 20mg that seems like massive overkill.
Ok, 20mg is not practical because it's to small and or / might mix with your secondary if not correctly pressed.
But 300 ?
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twelti
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Regarding pressing of either primary or secondary, is it not possible to press it slightly wet, and then include some desiccant inside the (sealed on
both ends) det cavity? Seal, crimp, or whatever, and let the energetics dry internally?
Second: Does anyone know if there are incompatibility with epoxy glues and SADS or ETN/PETN? Seems like I read some story about someone who left out
some epoxy with peroxide ini it and his dog stepped on it. Yikes!
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XeonTheMGPony
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| Quote: Originally posted by Herr Haber | 300 mg ?!
When ETN / PETN is initiated by as low as 20mg that seems like massive overkill.
Ok, 20mg is not practical because it's to small and or / might mix with your secondary if not correctly pressed.
But 300 ? |
For some one just starting it is better to go massive over kill to ensure full initiation, Vs some one ending up with a live fissled cap sitting on
top of a main charge!
As they gain practical experience they can start going smaller as they learn the art n science of dets.
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Laboratory of Liptakov
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Xeon says wise words. For beginners is better bigger cap-charges with lower density. And step by step, with bigger experiences and quality cavity and
tools is possible go to on on smaller det. cap with high density.
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Herr Haber
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You are both of course absolutely right 
Thank you for reminding me that this can happen.
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FeedMe94
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You are both absolutely right , like Herr said. As always !!
Science madness is the best school i could ever attend
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C6(NO2)5CH2CH(CH3)N(NO2)2
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| Quote: Originally posted by twelti | | Second: Does anyone know if there are incompatibility with epoxy glues and SADS or ETN/PETN? Seems like I read some story about someone who left out
some epoxy with peroxide ini it and his dog stepped on it. Yikes! |
I've read that story too. It wasn't completely clear whether the epoxy reacted and made the compound more sensitive, or if it was just a mechanical
effect of holding it together in a brittle block. peroxides are pretty sensitive already. As far as nitrates and acetylides are concerned, that's a
really good question-that I don't know the answer to.
https://www.thevespiary.org/rhodium/Rhodium/www.roguesci.org...
Incidentally, Does anyone know if that archive is a complete copy of the roguesci forum, or are there other threads that did not get incorporated into
the mirror?
Put that in your pipe and smoke it!
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twelti
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tubes
So, I think I understand the reasoning for metal tubes. Protection of the inside, and possibly confinement for some materials. Aside from the
confinement issue, I'm guessing that commercial dets must use sturdy metal tubes since they never know what handling there may be in the field -
transportation, construction sites, etc. BUT for me, I only need to make it from my basement to the back yard (or in the near future to a bucket on
sawdust IN my garage - a la Liptakov). In an extremely controlled environment like that, is there any advantage to metal tube? Does the confinement
around the sides, together with minimal confinement on the business end add to the initiating power?
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Laboratory of Liptakov
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With the exception of shrapnel, the solid cavity contributes positively to all necessary parameters for the detonator. Reliability, durability, easy
filling and so on........LL
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Herr Haber
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@Twelti: Factors affecting the efficiency of detonators.
Get that pdf from the library. It was truly an eye opener for me. This should help you answer some of your questions.
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twelti
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| Quote: Originally posted by Herr Haber | @Twelti: Factors affecting the efficiency of detonators.
Get that pdf from the library. It was truly an eye opener for me. This should help you answer some of your questions. |
Very useful, thanks. i wonder if it can answer the question: is a smaller metal tube det more or less safe as a larger less confined det of same
initiating power? I'm sure that depends on many other factors.
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Herr Haber
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I'd say that with a smaller tube you'll make a more efficient detonator that what you'd do in a larger tube with less confinement and lesser density.
If it's less dense it's VOD will be lesser and will probably be "safer" to handle if things go wrong.
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MineMan
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Industry detonators are thin Al tubes. With a steel sleeve surrounding the primary. Ideally. Very thin tubes are wanted as we want energy going into
the explosive not accelerating the case/tube. But for DDT strong tubes are usually needed. However I have had success in a carbon fiber arrow tube.
But the ddt formula for that is complex.
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FeedMe94
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I made a small detonator with 300mg recrystalized ETN slightly press inside a plastic 2ml tube. The rest was filled with al foil and ignited by visco
fuse. It sounded like it detonated but im not sure if it went full order.
  
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