Sciencemadness Discussion Board - Cap design

Cap design

prometheus1970 - 7-2-2011 at 15:50

The other day I finished another Ag2C2.AgNO3 DS synth. This time I put it all away properly so no accidents while testing. I put together a cap (of my own dubious design) consisting of .75 gram of ETN in the end of a disposable razor handle, 2 grams NC on top of that. Then I put .2 grams of DS into an empty .22 shell and put fuse in there and crimped the open end shut. I even thought to cover the part of the fuse inside the plastic handle, but outside the .22 brass with al duct tape to prevent sparks from igniting the NC (thus bursting the cap before det). Tomorrow I'll test another identical.22 initiator (just the shell with DS and fuse) to see if the primary will rupture the ass end of the .22 casing thus transferring maximum energy to the nitrocellulose. Also I sealed the fuse/.22 initiator into the handle with A-B epoxy. I wonder if only the DS detonates, if that will provide sufficient energy to initiate something like ANNM/Al after having to go through the plastic handle. What do you think guys? Viable, or should I just stick with DS wrapped up in tape with fuse(or even something else)?

[Edited on 2-8-2011 by prometheus1970]

[Edited on 2-8-2011 by prometheus1970]

gnitseretni - 7-2-2011 at 16:22

I'm not following your design but it sounds like your over complicating things.

Just get a piece of tube. Crimp the end shut or use epoxy. Press ETN in first, then your primary. Stick your fuse in the primary and close it with a little epoxy (or VERY carefully crimp it- but I don't recommend it). I think some folks use a little black powder on top of the primary. I'd keep it a simple as possible, but you can get as fancy as you want.

SB15 - 7-2-2011 at 18:46

I don't understand the fascination people have with metal caps. With a decent primary, there is no need for anything more than a thin plastic tube; a .22 casing or crimped metal tube only creates additional shrapnel danger.

A compound cap is a simple device. Cut a plastic straw to length and seal one end with hot glue. Press in your base charge with a wooden dowel. Press the primary directly on top using the same dowel. Insert a fuse/e-match and seal the remaining end with hot glue. Done.

[Edited on 2-8-2011 by SB15]

prometheus1970 - 7-2-2011 at 19:34

I thougt of the shrapnel issue, but I thought that if, immediately upon detonation the metal cap causes detonation of the main charge, wouldn't the inward-directed pressure of the secondary explosion force any shrapnel back towards the center of the explosion? I know this theory is half-baked at best, but I would like some feedback.

gnitseretni - 7-2-2011 at 19:55

He recommended a plastic tube for safety of handling. Once its positioned in the main charge, worry about the main charge, NOT the cap

mnick12 - 7-2-2011 at 20:01

Well shrapnel tends to fly in ever direction now matter how the explosive detonates. In an ideal world when one detonates an HE mixture one should be far enough away that there is no possibility of being hit by shrapnel. Also keep in mind that if you are detonating your mix on or in dirt there is a good possibility that any rocks will be become shrapnel. Also for det caps, you will rarely need more than .75gr of total explosive(s) in your cap unless you are dealing with some really stubborn HE's, in which case you should consider a booster. Anyway there is nothing wrong with using a metal det cap (I prefer a .223 shell that has had it's top rim cut off), but if you are afraid of flying pieces of metal plastic pen tubes work nicely.

SB15 - 7-2-2011 at 21:23

Quote: Originally posted by gnitseretni

He recommended a plastic tube for safety of handling.

Exactly.

As for metal caps, I know a person who has a piece of a commercial No.6 cap lodged in their palm, and given the typically higher sensitivity of the compositions we work with, that's enough to keep me away.

[Edited on 2-8-2011 by SB15]

mabuse_ - 8-2-2011 at 01:56

Quote:

I don't understand the fascination people have with metal caps. With a decent primary, there is no need for anything more than a thin plastic tube; a .22 casing or crimped metal tube only creates additional shrapnel danger. A compound cap is a simple device. Cut a plastic straw to length and seal one end with hot glue. Press in your base charge with a wooden dowel. Press the primary directly on top using the same dowel. Insert a fuse/e-match and seal the remaining end with hot glue. Done.

Metallic caps are much more dangerous to produce, but on the other hand much safer once finished.

Imagine you bend a straw-type blasting cap by mistake? And what about ESD?

Does anyone have any data on Ag2C2.AgNO3s sensitivity to ESD?

prometheus1970 - 8-2-2011 at 06:09

What is ESD? any relation to LSD?

prometheus1970 - 8-2-2011 at 06:28

I'm also very hesitant to use hot glue on a primary as heat sensitive as Ag2C2. I realize that the dangerous temp range for this primary is probably well above the temp of hot glue, but a margin of safety certainly won't hurt anything. As for the shrapnel issue, a .22 shell only weighs .6 grams, most likely not enough brass (|in flat pieces) to dangerously travel the 200 feet or so where I'll be standing.

prometheus1970 - 8-2-2011 at 07:44

I tested the .22 case with Ag2C2.AgNO3, it blew completely apart; it will definitely impart most of its energy from within that casing. I also made another cap of simpler design. A piece of dinking straw(with epoxied fuse) with 100 mg acetylide pressed against the fuse tip, then with 1.2 grams ETN pressed onto that, then held inside the straw with just enough Elmer's to keep stuff from falling out, but not enough that it wouldn't harden(thick gobs of pva glue tend not to harden all the way through).

[Edited on 2-8-2011 by prometheus1970]

quicksilver - 8-2-2011 at 08:41

Due to the posting limit of 2Mb because I would tack up some advertising that could just as easily be deleted later to show how things have changed over the years in energetic chemistry and physics elements re: design (& implementation) of initiators. But that would be lame illustrative advertisements which the science within could be summarized. If anyone really DOES want to see all sorts of commercial items in PDF format, PM me and I'll dig them up and pin them or send them to some site. Detonators are today termed initiators, as they preform more functions as time goes on. explosive bolts became extremely important not only to the aircraft industry but to NASA. To control time, direction, & amount of work via energetic materials became more complex as different materials arose to meet the issues involved in (not only) mining and urban reconstruction but geology & will eventually be a standard for geological exploration not only in deep sea environments but space as well.

How are we going to mine on the Moon except to make DuPont wealthier???? (Sorry- I could help that)

First of all, the shape of initiators have changed from the 6mm standard. {It used to be that NATO forces and commercial issues had a 6mm ID while Warsaw pact countries had a 6mm OD.} The standard was a tube (cylinder) for a few reasons; the more important ones were ease of use & mfg. Costs have risen so high, it's unbelievable due to tracking & serial numbers, one for each detonator one for who, where, and what mfg that unit, etc. That's a LOT of numbers! The unit also may be used in seismic & geological applications as well as doing work as per mining.
Of course the science behind that has also changed. The shelf life needed to be increased (fulminate caps actually rarely lasted more than a year. generally in hot climates they did well to last 6 months. The units now must also be waterproof and (usually) have more that one method of employment (Nonel & electric, etc) but most important still is their primary job which is to transmit shock from one point to the next. The body must be of a material that "shatters" rather than "balloons" so a unique type of aluminum is used that is also anodized and then coated with a polymer. The seal is solid obviously and the only other opening is the initiation point. Many are now enclosed in a small box-like plastic housing*, others are no longer a 6mm cylinder tube. (General source: Explosives Engineering magazine) What once cost $2.50 a box of 100 fuse caps are now (occasionally) $39 a carton of six units! Typical "fuse caps" are for the most part no longer mfg in the USA & in fact I know of only one mfg in Asia that still makes the standard 6mm X 66mm #8 (I don't remember how long the #6 was but it was about 6cm or a little less). Caps were made longer than the level of the ingredients for safety. They had to have some "crimp room" at the top and their seal had to be a very special highly flammable nitrocellulose, waterproof material that sealed the cap but allowed the fuse spit to easily contact the seal with crimp a good distance from the component element(s). EBW detonators are generally made by the same company that mfg the "blast box" (or visa versa) & are extremely expensive. Now coded signals are employed with signal strength & encoding units so that wires are really no longer needed on distance or safety sites.

But the basics have remained. That initiator has to be of a strength that essentially insures that the product will preform. That means that the concept of "over-driven" units have become the norm. The "compound" style of det design has also become the standard as the less primary used; the safer that unit can be. It takes so little azide to initiate a compressed gram of RDX or PETN that it (the azide) does not even need o be exposed to the same compression levels. Research has shown that the more "brittle" the container, the better the shock transmission. So aluminum that shattered was also the norm of construction. This was usually the 5000 series of aircraft grade alloy that had great strength but when it did give; it shattered instead of ballooning outward (for nano-seconds) & pushing the detonator away from the secondary material.

* This accomplished several things: it made more room for numerical codes, it made them more difficult to loose, it made them easier to apply to flexible type cartridge products within a borehole.

Quite frankly I don't suggest anyone attempt to "make a detonator" unless what I had just written appears very old news. IF you are of university age and want to understand (and use) energetic materials, you can do so via various programs available to university student in a legal, supervised and education environment. Below is a sample of the programs available to those who have a true interest.

[Edited on 8-2-2011 by quicksilver]

Attachment: 2009ExplosivesCamp_01-copy.pdf (724kB)
This file has been downloaded 984 times

-=HeX=- - 8-2-2011 at 11:54

quicksilver: such courses probably are for the US... So for us Euro's I strongly suggest PAPER casings. Yep, paper tubes, one end crimped off, formed around a pencil. Dip in Sodium Silicate to add some strength (or epoxy... or NC laquer!), fill with pressed RDX/MHN/PETN/ETN, then your primary, a bit of pyrogen and an ematch. Seal closed by folding the paper and gluing, prior to dipping the resultant device in a lacquer or something to water proof.

Such caps (Assuming 1gr base charge) are good for most applications...

quicksilver - 8-2-2011 at 17:36

I'm fairly sure that in most applications that would be satisfactory. It's too bad that information has become so restrictive that legislation still focuses on "objects" & not behavior. ~-=(soap box warning)=-~
There may come a time when such a discussion is censored. In the UK recently a newspaper caught a lot of attention because they supposedly released too much "explosive-making information" in an article on "7/7".
~-=(soap box: off)=-~

We DO have some excellent schools of mining, explos. engineering, & urban reconstruction here. Mostly in the public (State) University system. Before the extensive NASA cut-backs there was a great deal of discussion of mining on the Moon within the next 30years.

prometheus1970 - 8-2-2011 at 17:55

So, are you saying that unless this is already old hat to you, you should get professional training first, bypassing all amateur experimentation?

quicksilver - 9-2-2011 at 07:47

Basically I believe in this hobby, that a person should study.....so that MANY of the common questions are no longer "common questions". Because that would mean that the individual has studied deeply enough so that aspects of safety, elementary synthesis, construction, & design ramifications have been covered in his learning to the point where the standard of discussions move into an area of actual "uncharted territory". I have good reason for saying this......

Let's say you could look back on all the dialog in this Forum since it's inception; you'd see the same issues raised again over time. And one of the most unique things are that they cover (perhaps) two books, Davis, & Naoum!
I would seriously bet a nice dinner that IF someone studied those two books to the point of KNOWING them as per an upper-level undergrad course; they would rarely have a question that repeated itself within any area of the forum. The level of creativity would soar and the safety practices would get refined & natural.

It's one thing to depend on a discussion for creative ideas, refining & entertaining certain practices, or think deeper into a certain standard of workmanship (synthesis). However the nature of what is discussed is the same as high energy weaponry or lab-level practices (lasers, plasma, etc). the basics should be a sound responsibility of the individual so that HE KNOWS THAT WHAT HE HAS LEARNED IS RELIABLE & AS SAFE AS IT COULD EVER BE.
The classic difference between amateur and professional is pay. What I am saying specifically is that there should (in a perfect world) not be a definition of amateur as meaning "lower-grade". The ability to know a great many of the questions asked are out there with NO mis-interpretation as to exacting science. People should defiantly experiment - no question (IMO). However they should begin their experiment with book in hand, rather than anyone's opinion from the internet or what have you.
The last thing I would ever want is any harm to come to a member of this Forum, & in saying so I would rather they never take my word for something that could be verified independently. Not because I would purposely write something incorrectly, but I'm just a human being & I make mistakes.

So, am I saying to respond to people with UTFSE? NO, not at all. But IF that person does their own studying from reliable sources, they can be reasonably assured of being safer, using the correct tools for the job, & certainly having building blocks for much more enjoyment of this subject!
What's more the level of creativity will rise to the level of common ground within a framework of a standard of understanding that has often been missing when the basics really need to be covered so that person understands WHY something will happen and what will happen rather than follow a recipe & essentially miss a great deal of learning that could be the door to a serious level of creativity.

Finally.....we need to face reality. We may not HAVE this information after several laws gain a foothold. I'm quite serious about that. To miss an opportunity to buy up several books that may become scarce or even unprintable would be a tragedy. In the UK there already is a standing degree of censorship. in the USA we were extremely close with the "Feinstein Bill" (Goggle: "Feinstein Bill, bomb making literature") to having a door slam shut on energetic materials literature or even open discussion. Gentlemen, that Bill is now law. How long are you going to wait to develop, retain, & study - materials that may be as rare as the subject itself?

grndpndr - 9-2-2011 at 07:54

Not trying to be a smart ass but A good bit of whats been discussed and far more has already been talked about at lenghth from basic/more advanced reinforced caps,to energetics--primarys-secondary composite caps etc etc.

All you need do is search the site for detonator design-blasting caps and your sure to find far more than expected.Siteds that are relavent dating back to '05' at least.Its a real good Idea to check first to see if the topic isnt simply a repeat.But of course if you feel youve got something new..Please share.

+1 in agreement w/QS.If you must experiment try to do so within the law, and safely.

I am retracted/apologizing for the post that continued if legality, safety was of great Import joining the military as a demolitions engineer would be exciting for the adrenilin junkie.

But I realized many here are of age(18+) and at this point my patriotism for this adventure(middle east) is waning rapidly.Not to mention I suspect many contributors are old enough to have son's of military age like myself. My apologys

[Edited on 9-2-2011 by grndpndr]

[Edited on 9-2-2011 by grndpndr]

[Edited on 9-2-2011 by grndpndr]

grndpndr - 9-2-2011 at 11:27

I would like to have access to a synthetic casing maybe similar to what was used for HG fulminate back in the day.My belief it was bakelite.Very strong but brittle in thin pieces and light which should minimize fear of shrapnel.What I worry aboiut would be a det while in my hand not the small fragments of likely grain wieght Al.Likely leathger gloves of a decent thickness would stop said 'shrapnel' and eyeglasses at least or preferrably face shields.Lately if I were forced to work with detonators and primarys I would want some sort of hvy leather welding gloves along with the leather welding jacket ,witha full face shield plus my glasses.And Ideally a tool that allowed me to hold the cap at a distance from my hands while working on it.Even better a piece of plexiglass/polycarbonate bolted between vise/press det and me.

I think the nice thing about a stiff detonator container is it makes any pressing of the energetics safer by not allowing the flexible straw to move about during the operation.I dont see how the straw keeps from bursting?Unless of course the primary-secondary dont need compression,and just minimal confinement.

prometheus1970 - 9-2-2011 at 15:11

Maybe they'll turn out less than optimally effective, but I just use a few pounds of force when I press acetylide/etn in a cap, not enough to strain the casing, just nough to squueze most of the air pockets out of the material and make it as contiguous as possible. We'll se how these turn out...

grndpndr - 9-2-2011 at 16:49

I gotta say Im no chemist but on my worst day I wouldnt consider simply guessing as to the amount or density of the materials pressed into a detonator.Arent you at all interested in repeatable results and optimal use of expensive chemicals not to mention the time spent? (apparently not so much time spent with attention to detail)

Ive got a real bad feeling if your not bothering to wiegh or press your energetics to a known value for a blasting cap for chrissakes.What else are you just half assing along with?

That attitude will get you hurt.Sooner rather than later Id wager.

quicksilver - 9-2-2011 at 16:58

Ensign Bickford (the fuse mfg) experimented in the 1950's with a PBE (plastic bonded explos.) cap. It was actually ALL explosive. It was less than an inch wide a cylinder of hard explosive plastic that screwed on to the end of a fuse with "barbed" threads (in a 6mm hole in one end of the cylinder) that would keep it in place. It's concept was for touching off dynamite that was fixed into a hard borehole but did not detonate. It would be totally water resistant and when in place could withstand direct water contact. It could also be designed with a molded pair of leads for an internal bridge-wire, making it able to be used with almost any manner of initiation. The actual formula is no longer under patent and is available to those who have a fair background in polymer chemistry. It's not a lightweight thing to mfg.
The idea eventually was bought and now Sandia Corp is doing research in a similar area: that the cap as a whole is the detonator - in & of itself.

pjig - 9-2-2011 at 19:41

@Quicksilver

This almost sounds like a form of nipolite...(Not sure if I spelled that one right). The old german type of grenades, that where A ddsp/pent or other energetic bound and hardened into the shape of a grenade. The material was hard enough that it could be threaded, and the det and fuse lever threaded into it. ( No need for a casing) ..

Is what your speaking of, a booster of types?

prometheus1970 - 10-2-2011 at 06:12

I have to admit that, while I find merit in/admire the scientific approach to this endeavor, my motivation is more pragmatic at this point. I'm still trying to get a firm grasp of the basics of energetics. I'm nowhere near the point of 'boldly going where no man has gone before' and expanding the knowledge base of this area of study. Right now I'm just trying to stay safe, out of trouble (with the law/wife), etc. once I have a good, solid grasp of what I'm doing, I'll apply what I've learned from books and experience toward coming up with something more innovative.

[Edited on 2-10-2011 by prometheus1970]

quicksilver - 10-2-2011 at 07:12

I would have to dig becasue there are about half a dozen energetic polymers. but I wouldn't be surprised if the Germans worked with them (1940's).
Polymer chemistry demands the correct starting blocks & is rather ridged in it's format. I have a book on synthetic rubber that covers a great deal of that issue; including all sorts of explosives; it's not a lightweight subject.

@prometheus1970 :
I'll share with you an interesting antidote; I have another hobby that I have MUCH less knowledge of: Extreme High Voltage applications.
High energy just trips my trigger. But the Forum I belong to is very strict. They don't allow anyone to ask for a schematic per se' (like a recipe'), there are some very serious safety rules (as you could imagine) but they actually don't just post them. Their feeling is something like "do your own work at the basic level or suffer the consequences". - Which I personally don't believe in, by the way*......(They have a great many rules....)
In that respect (electronic engineering), I am very much a "babe in the woods". Some of these folks (quite a few) have PhD's. But demanding that I grasp some of the formula has been very valuable BECAUSE it helped me put stuff together that was a major thrill. Demanding of myself the discipline to learn aspects of trig was not easy (there is a lot of complex arithmetic and trig in electronics formulas) and I still have a VERY long way to go so that I could get to the "creativity point" that you mentioned. But I do see it. I do see how by understanding certain aspects of the core science, it will make things more fun down the road. Frankly some of those issues are a real pain in the ass. The safety issue was very significant as well; I needed to understand what aspects of safety were of direct influence with a high (electric) energy lab. And they are somewhat unique.

I DO know where you're coming from, & I respect it. I believe however that "sharpening your own sword" makes for a keener edge. I's been very difficult for me to immerse myself in another hobby where I essentially have to start all over but it's been a very good experience. I remember asking how to determine the output current from a given capacitor and was simply given a formula. I hated that type of teaching. I like things explained. But it did help in that I HAD to find appropriate background as a starting place for the equation, etc.
I doubt that I would even be able to conceive of something barely new in electronics: I can't even picture such a thing. Thus far I've made a few Tesla Coils, Can Crushers, and application specific voltage multipliers; no big deal....but it's been fun.
Believe me when I say I understand where you're coming from.

* Warning another person from a really terrible mistake should never be dismissed as a Darwin Award phenomenon.

[Edited on 10-2-2011 by quicksilver]

hissingnoise - 10-2-2011 at 07:13

Quote:

. . . once I have a good, solid grasp of what I'm doing, I'll apply what I've learned from books and experience toward coming up with something more innovative.

I think the scope for innovation in cap-design is limited, to put it mildly!
And it's difficult to see how the current detonators could be improved . . .

quicksilver - 10-2-2011 at 07:35

From what I have read, micro-sized "repeater stations" have allowed encoded signals to be transmitted virtually anywhere; ending in a fiber optic cable (instead of wire). The terminus being a final energy multiplier, shielded from EM pulse and all except the last few meters would be recoverable.So that EBW detonators can be placed pretty much anywhere. And the EBW caps themselves have been "self grounding" so that even if placed in a position where an EM pulse were attempted it would be shielded. This was the "off-planet" concept of mining that NASA considered in space where EM pulse from Sun Spots presented a serious challenge. It has been tested and the "consumables" were the cap and ending of a fiber optic cable which cost would be negligible compared to the results. That's about as advanced as I have read about. But it couldn't have even been conceived 50years back. When "self grounding" caps first emerged as a common item in electric caps.

prometheus1970 - 10-2-2011 at 07:59

I may not be fully knowlegdable, but I'm wise enough to know I won't be reinventing the wheel. My point was not so much that someday I'll come up with something completely novel, but that for now I'll steer completely clear of speculation and stick with learning the basics. I found the Davis and Naoum books on Amazon, I'm just waiting for a little money (will be a week or so) before I can buy them. I look forward to sinking my teeth into something so meaty. I just hope I won't need a thorough knowledge of chemistry/physics before they make any sense to me.

[Edited on 2-10-2011 by prometheus1970]

hissingnoise - 10-2-2011 at 08:17

Quote:

I found the Davis and Naoum books on Amazon, I'm just waiting for a little money (will be a week or so) before I can buy them.

You can download Davis from the SciMad library and print it, so why buy it?

quicksilver - 10-2-2011 at 08:37

Quote: Originally posted by prometheus1970

I'll steer completely clear of speculation and stick with learning the basics. I found the Davis and Naoum books on Amazon, I'm just waiting for a little money (will be a week or so) before I can buy them.

[Edited on 2-10-2011 by prometheus1970]

I can fairly promise you that the basic aspects of subject matter we have discussed in the "Energetic Materials" section of this Forum are encapsulated in those two texts. AND included are very explicitly and well tested means of preparation of those materials!

Were you to refer to them constantly after reading them fully it's my strongest belief that you would have the same level of basic knowledge as most any who answer a query here.

Not only do I applaud your open mind to this but I believe that in terms of learning to understand basic chemical equations; you'll have little trouble.* Because within those texts the examples were not written to fully explain the dynamics but to offer alternatives & reference (in general). The addition of nitrogen for instance can be clearly understood by comparative example. In practical matters, you'll see why this symbolism made sense.

The safety discussion are a matter of common sense and I doubt (you particularly) have a reason to be told that initiator stimulus are the same as safety agenda. It's mostly heat, static, impact, friction, etc which actually has a similar bearing when you think about it. They all have similar properties in relationship to the molecule.

On another topic; I really DO believe that one day these texts will not be readily available. And just like someone stores ski's or fishing equipment away for a time you may develop other interests, but you would always HAVE available the classical directions to this hobby.
The only thing I wish that Davis had done was mention more of the storage stability of various materials as HMTD and Hg Fulminate need cold to remain in good condition while higher temps bring about degeneration. There is SOME materiel but you need to hunt (or really read the text completely & have great retention ability). Even ETN is mentioned (I believe in Naoum) but briefly while MHN is given more. I believe this has to do with what was economically viable at the time of writing, etc. Therefore there is an ENORMOUS amount of the nitric esters in order of economic viability.
Naoum was also translated from the original German, so I have a feeling that areas where translation isn't practical was omitted. I have a feeling he wrote more than what's there. But it's damn valuable, well tested, proven, & reliable.

* "If a man is intellectually hungry and has an open mind he will be fed well." (JDR 1955)

[Edited on 10-2-2011 by quicksilver]

prometheus1970 - 10-2-2011 at 13:40

I may not be in a position for academic (at a university) pursuit of this subject, or or even explosives camp, but I can certainly read the available literature on it. Any other recommendations you may have book-wise would be tremendously appreciated.

Bert - 10-2-2011 at 13:58

Skylighter has TL Davis COPAE available as a free download.

http://www.skylighter.com/offers/free-ebook.asp

Naoum is a bit harder to find, but I've seen it out there-

prometheus1970 - 10-2-2011 at 15:15

Thanks, but I just ordered it from Amazon about 5 minutes ago. Which is probably just as well; a paper copy would be easier to read.

holmes1880 - 10-2-2011 at 23:06

Man, some of you people been smoking crack. And I bet you synthesized it yourselves too. Wizard is on a whole different level.....

Anyways. Prometheus, pick yourself up and walk over to Bass Pro Shop and buy Bullseye smokeless powder(yellow bottle). 0.2g DS pressed should detonate it without problem. Improvise however you like on the design. DBSP needs some confinement, but a light cardboard tube will suffice.

Bullseye isn't the only one that works:
http://www.youtube.com/watch?v=qTwdg6XejpU

SB15 - 11-2-2011 at 07:29

Quote: Originally posted by holmes1880

Man, some of you people been smoking crack.

My thoughts exactly.

This place often reminds me of that Microsoft search overload commercial. Ask a simple question and receive pages of off-topic rambling in response.

quicksilver - 11-2-2011 at 09:23

Quote: Originally posted by prometheus1970

Thanks, but I just ordered it from Amazon about 5 minutes ago. Which is probably just as well; a paper copy would be easier to read.

I have a fair library of text and I find it's easier to read and refer also.

However somethings ARE really expensive (or rare) and the only way to get them on any sort of a budget is via a PDF. I would suggest FEDEROFF & URBANSKI in PDF form as the collection (we are talking about encyclopedias now) are just too expensive unless you know how to collect rare books.

Name: "Encyclopedia of Explosives & Related Items"
That's generally considered the source for an enormous level of gov't research (from about the 1960's. From there on out is much tougher to get research in sully bound format). I have gotten hard copy but it too real work to find them at anything approaching affordable prices. (some people want over $1400 per set). Referred to as PATR*. It used to be available via Gov't printing. NOW you get a seriously unique response when you inquire to buy them.... (if you get my drift).
That's Federoff. -= Urbanski is another encyclopedic group.
Originally I believe that the GPO charged $3 per unit for Federoff & now they sell for around $250 via eBay & Amazon (private sales).

But when you have a chance PM me; I might be able to help at least with PDF's of texts which are unaffordable. The two you're considering getting are the old classic research from about 1920-40 & are the general basis for MUCH future material. Some of the ORIGINAL Munroe material on Shaped Charge dynamics are available also if you know where to look.

* Picatinny Arsenal Technical Research

[Edited on 11-2-2011 by quicksilver]

grndpndr - 11-2-2011 at 12:04

Quote: Originally posted by quicksilver

Ensign Bickford (the fuse mfg) experimented in the 1950's with a PBE (plastic bonded explos.) cap. It was actually ALL explosive. It was less than an inch wide a cylinder of hard explosive plastic that screwed on to the end of a fuse with "barbed" threads (in a 6mm hole in one end of the cylinder) that would keep it in place. It's concept was for touching off dynamite that was fixed into a hard borehole but did not detonate. It would be totally water resistant and when in place could withstand direct water contact. It could also be designed with a molded pair of leads for an internal bridge-wire, making it able to be used with almost any manner of initiation. The actual formula is no longer under patent and is available to those who have a fair background in polymer chemistry. It's not a lightweight thing to mfg.
The idea eventually was bought and now Sandia Corp is doing research in a similar area: that the cap as a whole is the detonator - in & of itself.

It seems this would fit well with the DBSP/energetic
composite thread?Exact design criteria Ill leave to the imagination.But an electric squib/det made up of a sensitive powerful energetic combined with a small amt of plasticized DBSP just to hold the ETN etc in suspension with a few grams of sensitized DBSPplastic with a lesser amount of ETN incorporated molded around the electric squib/ det in the shape of a traditional blasting cap. Like a caseless ammunition waterproof w/o a need for a casing.maybe a laquer of some type to ensure no foriegn materials could contaminate the cap?

@ Bert. Thanks for the free link for downloading COPAE.I too prefer a hard copy but my finances are suffering as is!!

@ QS. In the same vien give a man a fish hell eat that day.Teach a man to fish and hell be fed a lifetime.(Or words to that effect)

[Edited on 11-2-2011 by grndpndr]

[Edited on 11-2-2011 by grndpndr]

quicksilver - 12-2-2011 at 08:07

Energetic polymers are a whole world unto themselves. Some are castable and are as solid as many common plastics in everyday usage. Glycidyl nitrate (GLYN & polyGLYN), Glycidyl azide polymer and the momomers of several like energetics are referred to in such acronyms as; NIMMO (Nitrratomethyl-3-methl oxetane & polyNIMMO, & the azidomethyl-3-mthyl oxetane (AMMO & polyAMMO), BAMO (& polyBAMO) - there is whole world of them now that are generally used for the internals of disposable castable unit like explosive bolts, etc.
Polymer science is a whole other issue. but there are compositions of a polymer and a standard material like HMX that have been used with much less investment. Polyamide resin has the "flexibility" to work with a large group of standard energetic materials for the same concept.
(See J. Akhavan for a great deal of documentation on this subject. The material from the Royal Society of Chemistry is now too difficult to easily obtain but much of the original work was theirs, I believe.) TTBoMK this is where the modern energetic material research is going. I have seen some material on azidomethyl-3-mthyl oxetane & it's not lightweight in that if you really didn't have a polymer chemistry background as well a fairly well equipped lab it would not be a walk in the park. Synthesis on a plant level would be a very serious investment. One can easily see how a cap made entirely from such a materiel would be a very interesting design.....

Of commercial energetics I believe that CL20 is one of the most expensive to produce but the PBX are certainly damn close in cost.
You can easily find some patents but really do NOT expect to run a lab via what's published for patents on PBX's as the "trade secret" agenda makes (what I've seen so far) fairly unreproducible. These are generally a thousand dollars per Kg on a contract basis; they are seriously expensive.

[Edited on 12-2-2011 by quicksilver]

rmacccian - 4-4-2011 at 20:14

so then i take it that using a.p. is definilately out of the question for primer use lol

rmacccian - 4-4-2011 at 20:16

that is only if one wishes to blow his hand and is weapon to pieces lol

rmacccian - 4-4-2011 at 20:20

i find that ammonium nitrate 50%with charcoal powder makes a very cheap but effective black powder if gun powder were ever banned nationally

Bot0nist - 4-4-2011 at 20:55

I imagine that using ammonium nitrate as your oxidizer would make a terrible choice for gunpowder due to the hydroscopy of NH4NO3. Why not just use KNO3, S, C? It has worked for centuries.

grndpndr - 5-4-2011 at 03:56

while reading the other day concerning commercial SP/DBSP and specifically softening it with a solvent then adding ETN as I had proposed and I assume other esters the ETN will "Blossom", were the exact word used. Meaning the ETN crystals would migrate to the surface of the SP
upon the solvent drying.My apologies for not recording the source but I assure you it wasnt fringe literature.IIRC it was a patent - other reliable source.

This is the first I recall hearing of the phenomena I hope I havent bored you all with old news or news thats difficult to verify.I will do my best to try to recall the source of the material.

Like some others here state of the art for me would be 1920s tech at best but a search of the forum will reveal an awful lot of excellent material concerning cap design,reinforced caps as well a plethora of within reach safe-effective primarys and suitable base charges.
A garage chemist/fabricator has his work cut out simply fabricating an electronic/fused composite cap thats as reliable and effective as its older counterparts and done SAFELY!! most here arent trying to'reinvent' the wheel
simply design a safe and effective one.

[Edited on 5-4-2011 by grndpndr]

[Edited on 5-4-2011 by grndpndr]

quicksilver - 5-4-2011 at 12:22

I personally haven't heard of ETN being used commercially (I would be pretty interested in the source, if you find it), however be that as it may....
The most easily measured characteristic property of an explosive is the velocity at which the front propagates into the explosive. The front of a detonation wave initiated at one end of a lg dia stick of explosive is found to approach a nearly plane shape & a constant velocity of propagation Therefore it seems reasonable to assume that a limiting velocity exists & that is in the limit the chemical reaction takes place in a steady propagation zone in the explosive. A mathematically traceable problem related to physical reality in this limit is that of plane steady detonation. (Fickett & Davis)
That is generally why the ideal detonation is a train with a base explosive of much high VoD (via chemical and density) is placed at the ending of the train; contacting (via wave) the collective mass of explosive.
RDX / RETN will always (at density) meet a higher wave potential than a simple detonator developed from a simple primary. We see “compound detonators” have replaced simple primaries at most every employment level.
Flow in a reactive medium however has a hydrodynamic element to it that is extremely interesting but generally the concept of a fluid detonator has not been approachable for a variety of reasons.
The best designs are not always the simplest in the majority of cases. The first fuse-cap / single composition designs very rarely achieved much over 4k msp. Thus the concept of "over-drive" (which has a debate in itself) was not achieved until much later designs making hydrodynamic elements & their commensurate phenomena unknown for most of the last century.

[Edited on 5-4-2011 by quicksilver]

grndpndr - 5-4-2011 at 16:44

The way I read it QS it was not a commercial preperation but experimental one where the ETN that had been incorporated into the NC mass with the sovent with adequate milling. The solvent evaporating. The etn crystals eventually migrated to the surface of the HE.
Spoken ofb by vthe poster as if the ETN had 'bloomed'(

specific descriptor) or risen to the surface where it could be plainly seen.My apologys if I misunderstood
i will do my best to find the source!

quicksilver - 6-4-2011 at 06:01

No biggy; I had done a lot of work finding material (commercial / public) on ETN - always curious.

Contrabasso - 6-4-2011 at 10:22

From what I read Erythritol is a natural product with natural variables and naturally variable extraction proportions. Probably it's a fine explosive, BUT would it be suitable for warlike purposes if it were only an infrequently available plant crop.

quicksilver - 6-4-2011 at 14:45

To the best of my knowledge it's (Erythritol) both...... I believe there is a standard method of processing that does not depend on total organic sourcing. That's why price dropped from what it had been at time of discovery of nitrated material. I actually have followed a commercial diabetic sugar substitute that utilized it named "TRUVIA". Plant get's their Erythritol at roughly $1.05 / lb @ several hundred pound level. Initially, it (ETN) was too costly to make any real impact in commercial mediums, thus it was put on the shelf from the popular Nov. 20th 1928 patent forward. Today...it may be a different story but there are so many alternative polyols and that level of sensitivity has placed it too far to the "primary" side of things (IMO) to make it viable commercially.
NOTE: "Truvia" is not a pure sourcing of Erythritol & would need to be purified, etc. Approx 5-10% adulterants (unk. product ingredients). Some sugar alternative sites have dropped Erythritol to the $3-4 mark per lb.pure (USP level).
Erythritol Trivia....Using Erythritol as a "sugar-subsitute" is actually GOOD for teeth as it can result in much less of an acidic condition within the flora of the mouth which would normally result in tooth decay. Using Erythritol would very likely result in substantially LESS tooth decay, etc.
Only opinion but it is the only sugar substitute that is really palatable & genuinely tastes LIKE sucrose. I am NOT sure if it would bake well in a yeast-combination (bread) bakery usage however.

[Edited on 6-4-2011 by quicksilver]

grndpndr - 6-4-2011 at 15:35

Quote: Originally posted by Bot0nist

I imagine that using ammonium nitrate as your oxidizer would make a terrible choice for gunpowder due to the hydroscopy of NH4NO3. Why not just use KNO3, S, C? It has worked for centuries.

That wouldnt be your sole problem.Abit of hygroscopity could be dealt with by using nitrated paper cartridges circa
mid 18th cent;.The problem would arise from trying to fire equvalaent amts plain BP- AN/Charcoal ammonpulver,(never mind that which contained some 10% nitraromatic,) in a weapon not designed to contain Ammonpulver pressures that would amt to a death wish. Realise also some mixtures of ammonpulver are very nearly the pressure EQIVALENT of modern DBSP!.In effect using ammonpulover in nearly any BP firarm modern/antique is an invitation to disaster and possible maiming- death. w/O a MODERN load manual FOR AMMONPULVER you may be making a bomb with a modern bolt action firearm let alone a ML.

[Edited on 6-4-2011 by grndpndr]

pjig - 7-4-2011 at 15:00

Quote: Originally posted by quicksilver

To the best of my knowledge it's (Erythritol) both...... I believe there is a standard method of processing that does not depend on total organic sourcing. That's why price dropped from what it had been at time of discovery of nitrated material. I actually have followed a commercial diabetic sugar substitute that utilized it named "TRUVIA". Plant get's their Erythritol at roughly $1.05 / lb @ several hundred pound level. Initially, it (ETN) was too costly to make any real impact in commercial mediums, thus it was put on the shelf from the popular Nov. 20th 1928 patent forward. Today...it may be a different story but there are so many alternative polyols and that level of sensitivity has placed it too far to the "primary" side of things (IMO) to make it viable commercially.
NOTE: "Truvia" is not a pure sourcing of Erythritol & would need to be purified, etc. Approx 5-10% adulterants (unk. product ingredients). Some sugar alternative sites have dropped Erythritol to the $3-4 mark per lb.pure (USP level).
Erythritol Trivia....Using Erythritol as a "sugar-subsitute" is actually GOOD for teeth as it can result in much less of an acidic condition within the flora of the mouth which would normally result in tooth decay. Using Erythritol would very likely result in substantially LESS tooth decay, etc.
Only opinion but it is the only sugar substitute that is really palatable & genuinely tastes LIKE sucrose. I am NOT sure if it would bake well in a yeast-combination (bread) bakery usage however.

[Edited on 6-4-2011 by quicksilver]

I believe that your right...., Erythritol is a sugar alcohol that bakes very diff than regular sugar. I believe that is has to be baked at a much lower temp to maintain in the food being cooked.

Nitrated sugars are quite good energy producers for sure...

grndpndr - 8-4-2011 at 17:50

My wife is diabetic as well and enjoys erythritol almost as much as the forbidden sugar though neither of us have tried to make cookies/ bake with it.
Still its not a product that can be bought locally Im aware of
although this is a very sparsely populated area.Better baking via erythritol!LOL

Cap Design

Recessive - 6-8-2011 at 17:03

Quicksilver says: “It takes so little azide to initiate a compressed gram of RDX or PETN that it (the azide) does not even need to be exposed to the same compression levels.”

Urbanski, V3 p177, has a table confirming part of this. Compressing primaries above 7,000 psi does not help their initiation performance (despite increasing peak pressure).

However, the commonly used US M213 fuze employs 0.3g azide, which is a large quantity considering that tables show, e.g., .03g azide initiating TNT. But this TNT is finely powdered, whereas the RDX or PETN in a blasting cap is compressed to a density of 1.4 (per Gerald Hurst).

A cap in which the output explosive is compressed to an average of 1.4 in one stage will have a density below 1.4 at the output end, and a density above 1.4 at the compression end. Possibly the densities at the two ends are as disparate as 1.2 and 1.6, and the density of 1.6 may require a significant amount of azide, 0.3g, for reliable initiation. I do not know how many pressing stages are typical in the manufacture of a cap. At any rate, it is the contention of the US Bureau of Ordnance that this large amount of azide is required for RDX at a nominal density of 1.4, and I go with that.

I checked tables of compression pressure vs. density for cyclonite in PATR, Urbanski, and Cooper, and they differ significantly, and I suspect it is because the lengths of the columns being compressed varies significantly, and in no case do the authors state the length.

Of interest is that the US military is considering replacing the RDX with a PBX consisting of 97% HNIW and 3% Viton binder. Although HNIW is more sensitive than RDX, in PBX form it may well be less sensitive than a compressed column of RDX. The density of the PBX is about 2.0, generating a pressure over twice that of RDX at 1.4. No pressing necessary.

Though the military can’t afford silver azide, I (we) can - still only a dollar a gram. Too much silver causes one to turn grayish-silver color, but that is the sole symptom of argyria.

I yearn for a cap with a closed end, but can’t get one. One solution is to leave it open, with the naked output charge at the end.

Also, in regard to sealing, I would like to know for sure whether curing epoxy next to azide leaves the azide unaffected. I would hate to have it increase sensitivity. How about silicone, which has acetic acid? Anybody know anything about this?

[Edited on 7-8-2011 by Recessive]