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Author: Subject: Det Cap Strategies
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[*] posted on 12-2-2023 at 09:33


well if you live in America it would be F and yes its a very large anti-static bag, it fits my whole house inside.
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[*] posted on 12-2-2023 at 10:05


This is an international science forum. Specifying units of temperature is important, and without specification it’s assumed to be Celsius by default, ‘Murica or not.



Come check out the Official Sciencemadness Wiki
They're not really active right now, but here's my YouTube channel and my blog.
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Herr Haber
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[*] posted on 12-2-2023 at 10:38


Quote: Originally posted by Herr Haber  


Doesnt seem to be any copper in those.



@Bert
Well... I was wrong ! I left the small beaker for a few days and after settling I am left with a very light blue solution.
I used "a few" dragon eggs but certainly less than a gram which would amount *at most* to 150mg given your composition. Said composition doesnt include the priming (black powder) on the eggs that seems to constitute most of the sediment (carbon).




The spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words 'act upon' meant. - Ira Remsen
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Fantasma4500
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[*] posted on 19-2-2023 at 02:26


dragon eggs have practically zero brisance, poor predictor for it being useful for initiation
i have seen dragon eggs on youtube that were pretty big in size and seemingly went off by fuse right away without smoldering first
however the smoldering part i have seen with copper sulfate and copper oxide compositions where its first superheated and then loudly and sharply explodes in open air, its possible to "charge" regular flashpowder by heating it up first as well

mixtures of our beloved sugar nitrate with primary-like binary mixes is more interesting, armstrongs mixture and sugar nitrate was found capable of detonating but the guy who played around with it didnt bother finding a working ratio of stability and detonating in open air, he rather just put a core of flashpowder sorrounded by the sugar nitrate

if you must, 10mm aluminium tube with 500mg of the sugar nitrate sealed in by 2 1mm aluminium foil discs, then a slowburning composition- such as liptakovs caramelite and a fuse leading into this with some KClO3 sugar mix to carry ignition, secured with cotton wool goes well, appears that maybe 50mg of the nitrate burns off rapidly whereafter it goes high order, the aluminium tube does not at the bottom get hot enough to ignite nitrocellulose- this means the tube doesnt get hotter than 120*C - essentially its safe to use in combustible charges without risking the charge burning up before initiation goes




~25 drops = 1mL @dH2O viscocity - STP
Truth is ever growing - but without context theres barely any such.

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[*] posted on 31-5-2023 at 08:36


Blasting cap protector

received_243381901630197.jpeg - 159kB
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[*] posted on 31-5-2023 at 14:54


Quote: Originally posted by specialactivitieSK  
Blasting cap protector


I would be interested to know more.
What does this actually do?
Is it to protect the user from an accidental detonation or the detonator from an accidental stimulus?
Without context it kind of just looks like a pipe bomb.
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[*] posted on 31-5-2023 at 23:03


protect the user from an accidental detonation
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[*] posted on 1-6-2023 at 08:18


Have you tried setting a detonator off inside it on purpose (and with proper safety measures)? A number 8 equivalent detonator really is quite powerful...
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[*] posted on 1-6-2023 at 14:53


Quote: Originally posted by Microtek  
Have you tried setting a detonator off inside it on purpose (and with proper safety measures)? A number 8 equivalent detonator really is quite powerful...


When I thought about the construction of such a device I imagined it would probably be better to have a thick walled inner tube with a lot of holes and an outer tube with less holes and kaowool in between all welded on a round plate and screw top on the other end
I realize that looks like a bulky sound supressor.




The spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words 'act upon' meant. - Ira Remsen
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[*] posted on 1-6-2023 at 16:12


Haber, a suppressor-like design that has some sort of baffles (facing the center of the cylinder rather than perpendicular like for a firearm) might work to break up small enough blastwaves for <1g amounts of EM. Although I think at that scale, the blast wave is less important to minimize than the shrapnel. If it’s possible to use a fiberglass insulated, kevlar or weaved carbon tube (wrapped around the long edge of the cylinder), the shrapnel and blast wave of an accidental detonation could be ‘caught’ by the threads of composite fiber (kevlar, carbon fiber, etc).

If you are trying to construct a magazine for bulk storage of EM though, with no shrapnel/metal casings involved, a setup incorporating big spikes (like sound deafening foam but made out of wood or some other compressible material) and baffles might be a good way to break up or at least slow down a blast wave before it can break out of the magazine walls.

Never store EM in a non-compressible material environment.
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[*] posted on 1-6-2023 at 16:55


Quote: Originally posted by Microtek  
Have you tried setting a detonator off inside it on purpose (and with proper safety measures)? A number 8 equivalent detonator really is quite powerful...


Plus one to this.
How is it constructed, what are the materials?
Do you have a photo of the internals?
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[*] posted on 28-6-2023 at 21:28


A while ago I made blasting caps using plastic pen bodies, but I have a feeling that the hardness of the plastic might have been the thing that was interfering with the explosive train. I remember once thinking about making blasting caps out of cardboard, but I never found a suitable tube for it.

I did, however, get some large paper straws (the type people use to drink bubble tea) and the larger diameter would make things easier for loading and pressing. But I also think that military caps made using cardboard bodies (such as Soviet detonators during WW2) had similar strength. Obviously some waterproofing would be needed, or at least wrapping them in electrical tape should do the trick.

I made a pair with CHP, albeit I didn't do more than hand pressing since I am still to scared to try to use my C-clamp to press harder on the stuff. I will need a better setup for it as well.

I want to try to see if I can meltcast ETN in a waterproofed paper cap. I sealed the end with 5-minute epoxy and I do believe that the melting point of epoxy resin is easily over 100C, so no need to worry about the plug melting on that end.
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[*] posted on 16-10-2023 at 18:57


So around two weeks ago I wanted to go out to a location I went to previously and test out my caps with a proper steel witness plate (pictured below) but sadly the weather was not what I anticipated. It was raining HARD, so I had to cancel my trip.

I once did ask how I would put my caps without gluing them on a metal plate, but I did find the following at a local hardware store (they also have the benefit of being dirt cheap). Would a cap taped to the side of the plate allow for proper force to be directed downward for a proper test to happen?

I promise, this is the last question I will be asking about caps before I go out and finally blow some holes into metal and see how my caps work.

IMG_20231016_222058910 - Copy.jpg - 1.5MBIMG_20231016_222103201_HDR - Copy.jpg - 1.5MBIMG_20231016_222333741 - Copy.jpg - 1.7MBIMG_20231016_222342393 - Copy.jpg - 1.6MB
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[*] posted on 16-10-2023 at 19:11


Tape will work fine as you have it. Best of luck with the weather for your next outing.
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[*] posted on 16-10-2023 at 19:48


Quote: Originally posted by B(a)P  
Tape will work fine as you have it. Best of luck with the weather for your next outing.


Thanks. Many of those caps were made last summer and I am itching to set them off. I also used the NHN/chlorate mixture that is covered in another thread. I will also be trying straight NHN in a brass 5.56x45mm/.223 case and one of the 1.2g of ETN + 0.5 of straight ETN in a longer, but slightly narrower, metal body.

That metal body you see appears to be ideal for most caps, since it is 8x50mm, given how loose the 6.35mm dowel that I used to press the stuff in there was, I assume it is a 8mm OD but 7mm ID, which makes it a very good diameter for most caps.
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[*] posted on 16-10-2023 at 19:55


Quote: Originally posted by ManyInterests  
A while ago I made blasting caps using plastic pen bodies, but I have a feeling that the hardness of the plastic might have been the thing that was interfering with the explosive train. I remember once thinking about making blasting caps out of cardboard, but I never found a suitable tube for it.

I did, however, get some large paper straws (the type people use to drink bubble tea) and the larger diameter would make things easier for loading and pressing. But I also think that military caps made using cardboard bodies (such as Soviet detonators during WW2) had similar strength. Obviously some waterproofing would be needed, or at least wrapping them in electrical tape should do the trick.

I made a pair with CHP, albeit I didn't do more than hand pressing since I am still to scared to try to use my C-clamp to press harder on the stuff. I will need a better setup for it as well.

I want to try to see if I can meltcast ETN in a waterproofed paper cap. I sealed the end with 5-minute epoxy and I do believe that the melting point of epoxy resin is easily over 100C, so no need to worry about the plug melting on that end.


More strength and confinement with a cap body is generally what you'd want. A paper straw isn't an improvement by any stretch.
You can find lots of suitable tubes of varying sizes at a dollar store or the arts and crafts section in a department store. Coloring markers and such.
Some 9v batteries contain 6 small 1.5v batteries wired in series that are just about the perfect size for a cap.
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[*] posted on 16-10-2023 at 20:35


Quote: Originally posted by OneEyedPyro  
Quote: Originally posted by ManyInterests  
A while ago I made blasting caps using plastic pen bodies, but I have a feeling that the hardness of the plastic might have been the thing that was interfering with the explosive train. I remember once thinking about making blasting caps out of cardboard, but I never found a suitable tube for it.

I did, however, get some large paper straws (the type people use to drink bubble tea) and the larger diameter would make things easier for loading and pressing. But I also think that military caps made using cardboard bodies (such as Soviet detonators during WW2) had similar strength. Obviously some waterproofing would be needed, or at least wrapping them in electrical tape should do the trick.

I made a pair with CHP, albeit I didn't do more than hand pressing since I am still to scared to try to use my C-clamp to press harder on the stuff. I will need a better setup for it as well.

I want to try to see if I can meltcast ETN in a waterproofed paper cap. I sealed the end with 5-minute epoxy and I do believe that the melting point of epoxy resin is easily over 100C, so no need to worry about the plug melting on that end.


More strength and confinement with a cap body is generally what you'd want. A paper straw isn't an improvement by any stretch.
You can find lots of suitable tubes of varying sizes at a dollar store or the arts and crafts section in a department store. Coloring markers and such.
Some 9v batteries contain 6 small 1.5v batteries wired in series that are just about the perfect size for a cap.


Yeah I figured that out. The batteries inside some 9vs are AAAA batteries. They can be purchased separately, but in many cases they're so hard to find nowadays that some people just get alkaline 9V batteries and open them up to salvage them. It's actually rather hit and miss. I've opened up many 9Vs from various brands (alkaline 9Vs) and some had column type, while others had the AAAAs.

But using them would be tricky since they need to be well cleaned from within. That is an annoying endeavor. I would rather just by the 304 steel capillary tubes that are already sealed on one end and call it a day. when melt-casting ETN in them, exceptional care must be taken since molten ETN is highly sensitive when with steel, Though I did melt-cast ETN in them several times without issue.

One thing I learned is that it is just better to use a metal cap body. I'm glad that I initially used plastic pen bodies because it did let me see if anything was going on with the material inside. When I first made ETN, I didn't wash it enough to get rid of all the acid, so a lot stayed left over. While it didn't appear to degrade it when I was storing it in a tupperware, but it did seriously degrade when I loaded it into a bic round stick pen body. After I properly cleaned and purified the ETN, all subsequent pen body caps showed no sign of degradation. While I did put a small cling film barrier between the ETN and the NHN, I don't think it was the NHN interacting with the ETN that was causing it, since I did make a small mixture of the two and let them sit together for a few weeks before disposing of them, and they did not show any signs of discoloration or decay.

In the other thread about mixing a 600:400mg ratio of NHN and sodium chlorate (with 20mg of dry bar soap added and minimum water) he said that if this mixture was put in a plastic pen body it would still work to set off ANFO. The issue with this is that my pen bodies are too narrow for that, and I would rather just use metal.
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[*] posted on 15-11-2023 at 12:04


I apologize if it’s been mentioned before in this thread or somewhere else, but I think spent 22 win mag brass (properly cleaned and polished) could work well as a det cap for both standard fuse and e-match caps. They are around the right ID of a little under 1/4” and are easy to widen and crimp as needed. E-matches sold in the US (the ones with blue & white wires and a red cap to surround the match head) fit snugly inside the brass with a small amount of pressing and 1/4 fuse can be made to fit as well. I found that a rounded steel rod (like a centering punch) and a few blows from a rubber mallet can widen the case ID to 1/4” no problem.

I figured a priming mix of dextrinated AgNTz against the match/fuse followed by a small cotton plug and then pressed, waxed PETN or RDX behind could work. The only issue would be space since the overall length of the casing is about 1” (25mm) and you’d need a solid 5mm or more just for the crimp/glued portion of the cap.

If anyone has info on using spent rimfire casings as caps or the use of AgNTz as a primer I’d be glad to discuss. AgNTz really doesn’t have much info relating to practical use, all I have read is that it can’t be used in combination with Al metal, tetrazene, or MTX-1. It is compatible with RDX but I haven’t heard about it with nitrate esters.
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[*] posted on 17-11-2023 at 13:20


Quote: Originally posted by dettoo456  
I apologize if it’s been mentioned before in this thread or somewhere else, but I think spent 22 win mag brass (properly cleaned and polished) could work well as a det cap for both standard fuse and e-match caps. They are around the right ID of a little under 1/4” and are easy to widen and crimp as needed. E-matches sold in the US (the ones with blue & white wires and a red cap to surround the match head) fit snugly inside the brass with a small amount of pressing and 1/4 fuse can be made to fit as well. I found that a rounded steel rod (like a centering punch) and a few blows from a rubber mallet can widen the case ID to 1/4” no problem.

I figured a priming mix of dextrinated AgNTz against the match/fuse followed by a small cotton plug and then pressed, waxed PETN or RDX behind could work. The only issue would be space since the overall length of the casing is about 1” (25mm) and you’d need a solid 5mm or more just for the crimp/glued portion of the cap.

If anyone has info on using spent rimfire casings as caps or the use of AgNTz as a primer I’d be glad to discuss. AgNTz really doesn’t have much info relating to practical use, all I have read is that it can’t be used in combination with Al metal, tetrazene, or MTX-1. It is compatible with RDX but I haven’t heard about it with nitrate esters.


.22WRM having a .224 ID you can use a .22LR or better yet .22 short as a plug and housing for the primary since they are heeled type cartridges.
I've done this with SADS/ETN to decent success by pressing and gluing the cases together. The charge is a bit small for my liking and the rims can be an issue when inserting or attaching to a main charge but they will set off ANNM and Tannerite just fine.
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[*] posted on 25-2-2024 at 00:47


OK so finally I drove out in the middle of nowhere to blow some caps. I originally intended to set off 6 caps, but I had some issues and some hestitation. I tried to set off 3, but one had an issue and didn't go off, but the other 2 did.

The set up was that I went out into a snowy field and partially buried the witness plates with the cap taped to it and then set it off. As it was resting on snow, the explosion pushed the entire thing down instead of blowing a hole on it. It isn't the most ideal of circumstances, but I did what I could under the circumstances. I dug the metal pieces out after popping them.

I put an intact piece of metal for comparsion. The bent one used a 0.9g of NHN/sodium chlorate charge, while the really warped one used a 100mm long cap with 1.1g and 0.3g of melt-cast and powder ETN respectively, and 0.5g of NHN as the primary.

I think both of them are quite the success.

witness - Copy.jpg - 3.8MB
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[*] posted on 25-2-2024 at 13:22


What did you do with the UXO cap? I know the standard procedure is to wait 20 min, fire again, then wait 20min and set it off with a reliable remote charge but there aren’t many instances of a well-documented situation like that.

Also, I’d assume those pieces of metal should’ve been decimated with the close to & above 1g quantities of EM. Though, the only real point of the cap is to get a secondary initiated, and that can be done with <800mg PETN in some cases.


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[*] posted on 25-2-2024 at 15:36


I did wait, and I probably gave it more than 20 minutes, too. I moved it aside to detonate the others. The thing did not go off.

I should have written why I suspected the other cap didn't go off (it is with me right now) is that I was trying to see how much I can cram into it. I used some of my poor quality NHN (it doesn't burn very fast) and did with the sodium chlorate addition and soap. As I was plugging in the e-match, it didn't go all the way in like in my other caps. I still put in some epoxy and due to the looseness of it, I think there was a layer of epoxy between the e-match and the epoxy that blocked ignition.

I made a 2nd one like it, but I did not try to set it off. The next time I go out. I will tape them together with another cap I know will go off and have them all pop together.

Quote:

Also, I’d assume those pieces of metal should’ve been decimated with the close to & above 1g quantities of EM. Though, the only real point of the cap is to get a secondary initiated, and that can be done with <800mg PETN in some cases.


That is true. This test was to simply get to make sure that my caps function as intended and can do the job. I had difficulties with other caps in the past, but that was due to them using plastic pen bodies. The reason why there wasn't more damage to the plates is because there was plenty of space for the metal to be forced into (snow isn't exactly hard). If I placed the plates on a solid surface there would probably be a lot more visible damage to the plates. Even the pure NHN one (NHN-chlorate mixture) was quite powerful and I think it'll set most anything off. The one with the 1.1g ETN charge is extremely powerful.

At this point I am confident with these and the next time I go out I will bring a small ammonium picrate charge (in a thick cardboard tube) to try a 1.1g of NHN-sodium chlorate charge and se if it'll detonate. I made ammonium picrate specifically for this test: It is the most insensitive secondary outside of ANFO.
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[*] posted on 25-2-2024 at 23:44


If the caps detonate fully, it won't matter what it is resting on. Like shooting an apple hanging on a string, the event is much too fast for the target to move anywhere before it is penetrated. I think you should save your picrate for when your caps work better. Also, I think ammonium picrate is generally used with a booster, so you should a least use a very beefy detonator.
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[*] posted on 26-2-2024 at 02:38


Quote: Originally posted by Microtek  
If the caps detonate fully, it won't matter what it is resting on. Like shooting an apple hanging on a string, the event is much too fast for the target to move anywhere before it is penetrated. I think you should save your picrate for when your caps work better. Also, I think ammonium picrate is generally used with a booster, so you should a least use a very beefy detonator.


I can make another large detonator?

The charge I intend to set off is around 30g charge. I have more to try at later dates if my cap doesn't work.

The NHN composition that I used was made following this thread: https://www.sciencemadness.org/whisper/viewthread.php?tid=15...

he did say that 1g loading was able to set off AN based secondaries. If the AN he is referring to is ammonium nitrate it should be sufficient.

Is the 1g detonator not good enough in your opinion? I posted more pics of the plate.

[Edited on 26-2-2024 by ManyInterests]

witness2 - Copy.jpg - 3.4MBwitness3 - Copy.jpg - 1.8MBwitness4 - Copy.jpg - 1.9MB
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[*] posted on 26-2-2024 at 05:38


How were thickness of plate? 1,5 or 2 mm? Anyway, the your hole is weak. 1g ETN must causes circle hole minimal 10 mm. On second photo is plate 2 mm and 0.4 g ETN.



1g etn22 (1).jpg - 228kB pic5aa.jpg - 465kB




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