Sciencemadness Discussion Board - DDNP & related compounds: The über thread!

DDNP & related compounds: The über thread!

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Hennig Brand - 9-2-2014 at 06:40

@roXefeller
Yes that is true, good observation.

@Rosco
Thank you for the great piece of reading. I have only given it a quick look, but I am going to sit down and read it carefully very soon.

Success Initiating Picric Acid at 7.6mm id with 0.7g of DDNP

The same setup as was used for the 1g DDNP test above was used. This time, however, instead of 1g of DDNP only 0.7g of DDNP was used. Also, instead of 2g only 1.5g of Picric Acid was used, which maybe I shouldn't have changed. The DDNP was not recrystallized. One gram of picric acid was pressed into the detonator capsule with a lever press and then another 0.5g was pressed in by hand. DDNP (0.5g) was pressed into the homemade reinforcing cap and 0.2g of DDNP was poured into the detonator capsule loose on top of the picric acid base charge. Care was taken to not overpress the DDNP. Finally the reinforcing cap full of DDNP was pressed into place in the detonator capsule, with the lever press. A little loose black powder and visco fuse were put in place and the open end sealed with a bit of hot melt glue. The 0.7g of DDNP detonated the picric acid, which makes me feel that using 1g of DDNP in this configuration should be reasonably reliable.

From the pictures it can be seen that the hole produced in the 3mm thick steel witness plate is not as large or clean as from the last test. Two things were different in this test. The first was that only 1.5g of picric acid was used. The second was the way the bottom of the cap was waterproofed. For the first test, the cap bottom was waterproofed with a thin layer of lacquer, but this time a corner was cut and a bit of hot melt glue was smeared over the end. The lacquer had negligible thickness but the hot melt glue was estimated at over 1mm. The cap and witness plate were not as well connected for this test.

BTW, the hole on the right in the pictures is the one corresponding to this test.

[Edited on 2-13-2014 by Polverone]

Rosco Bodine - 9-2-2014 at 07:27

It will be found that there is information in the literature with which I do not agree about the conclusions and analysis of what is occurring. I believe that testing based on weight scaling of charges without scaling the weights according to the geometry will skew results and lead to incorrect conclusions about for example the "efficiency" of detonators with regards to performance alone and without regards to economy of materials. The focus of the research done seems biased towards economy of materials alone, but tests are not done to show the actual performance increase or maintenance of the performance as a function of geometric scaling for different diameter detonators.

I believe that the early researchers and possibly later researchers as well have erred in the supposition that geometric scaling is not very much a factor in detonator scale explosive devices. To illustrate what is my meaning, for example with regards to the Miniature Cartridge Test, if the amount of primary used for the larger diameter detonator was scaled upwards geometrically along with a proportional scaling increase for the base charge, I believe that there would be a greater than arithmetic proportional bump in the performance as measured by the sand test as would be expected by simple multiplication. Such tests are conspicuously omitted, because they would likely reveal a parameter about performance without regards to economy that is not wished to be highlighted.

The minimum effective initiating charge for the smaller diameter should be increased for the larger diameter detonator output potential to be realized. There is an aspect called "overdriving" which applies to reveal the true performance potential of a detonator generously larger than its critical diameter, where "performance" in terms of economy of materials is secondary to reliability and potential output that can be realized, without being constrained by highest economy of materials as defining also what is to be regarded as being the "highest performance". Some evidence of this is shown by the plate tests which would seem contradictory to the Miniature Cartridge sand test. The plates are actually showing the truer result that would likely be also revealed by the sand tests if the proportionally increased diameter detonators were also proportionally greater primed with a proportionally increased amount of initiator also matched with a proportionally greater base charge. I predict that in such case there would be a proportionally greater output shown by such tests not done. And I also predict that the failure rate would be lower for the larger diameter detonators, loaded at a comparable multiplier increase beyond the minimum loading found to produce a true high order output for 10 out of 10 tests. The larger diameter detonators will have a failure rate that is lower as the initiator loading is decreased towards what is the bare minimum requirement.

For example the "operational theory" applied by the naval ordnance designer, will differ considerably from what is the operational theory of the bean counter at the bureau of mines.

The coal miner may rely upon a lot more duds as a result than will any 16 inch shells or torpedoes or mines be found failing to go off at their appointed time.

Your tests are showing the effect of "tuning" the device parameters. For specific materials you will find there is a reliable configuration, and there will be a range of factors that define what are its design limits and expected performance. If you are familiar with handloading ammunition and working up a load that works well for a specific combination of components, you will recognize the parallel of finding what combination works by trial and error and charting the results which can lead to a highly refined configuration for the components being used.

[Edited on 9-2-2014 by Rosco Bodine]

Hennig Brand - 9-2-2014 at 08:03

Good points, there are a lot of important parameters left out in a lot of the literature regarding detonator efficiency. I really wish I had kept the base charge weight the same for all tests. I was getting a little low on detonator grade picric acid, but I still should have kept the base charge weights the same. I do feel a lot better about using 1g of DDNP to initiate picric acid in this configuration though. Nice to know that 1g is not that close to the bare minimum.

I am familiar with hand loading, but I haven't put a lot of time in at it. I know people who have done a lot of hand loading though. When I was 13 or 14 I got a set of dies, powder and other equipment for reloading 223 rounds for my rifle (given to me the previous year). My brother was given 30-06 equipment and rifle (I felt a bit cheated). The 223 rifle was much nicer than the 30-06 rifle though.

[Edited on 9-2-2014 by Hennig Brand]

Rosco Bodine - 9-2-2014 at 08:36

At a 1/4" column diameter for the base charge initiated by lead azide, a 1.5 grams base charge of picric acid loaded in quarter gram increments is about optimal. Going up to a 5/16" column diameter then 2 grams is about right and will work for 3/8" also but can even increase to more at 3/8". I have gone as high as 3.5 grams of PETN at 3/8" and it is overkill but can go that high if a special is being made for use without a booster for an insenitive secondary that would ordinarily require a booster, but is more convenient and wished to be used with a cap alone. 2 grams of picric acid will likely set off most insensitive and hard to initiate secondaries that are barely cap sensitive like urea nitrate.
Urea nitrate is actually a good test of a detonator, or what a detonator should do in my estimation. If your det can reliably detonate urea nitrate unconfined, then it will likely be sufficient for anything else considered to be cap sensitive.
A 1.5 gram base charge of picric acid can do it but 2 grams is more guaranteed reliable.

One of the things that was interesting about the paper I attached earlier is the superior results being reported for RDX versus PETN which seems to be an anomaly. The military uses an RDX base charge but PETN has been regarded by most to be superior at small diameters like for dets or det cord. I have seen conflicting reports about this, but have never made it a study to learn what is the real story there. Another loading that would seem interesting would be using triaminoguanidine perchlorate as an initiator for a guanidine perchlorate base charge. I have never seen it described in the literature.

Ral123 - 9-2-2014 at 08:58

I know I show a big incompetence here, but in metal case, the base charge can be hammered with a sturdy rod(I used steel to hammer for one of my TNP tests) if you don't have press right? I have the feeling steel hammer and steel rod can easily dead press some materials. For the primary I use dense paper rod and rubber hammer. The large amount of gentle hits would allow the material to rearrange itself and become very compact. Am I right in my assumption that that way high densities can be achieved at home?

Rosco Bodine - 9-2-2014 at 09:11

If you don't have some kind of elementary press fixture then make one. A hammer and loading energetic materials is a really bad idea. An elementary kind of loading press can be made from a heavy duty caulking gun frame.

Hennig Brand - 9-2-2014 at 09:31

That lever press, shown in the pictures a little farther back in this thread, was made from scrap wood and took 30 minutes or less to build. The two bits of metal plate, for the pressing surfaces, where attached soon after when I realized they were definitely needed. The press has been in use for several years now. During pressing one can stay at a much safer distance, and can even put up some sort of barrier for added protection.

Hammering seems like a really bad idea.

Rosco Bodine - 9-2-2014 at 09:48

File of interest. There is some comment in the attached file about the plate test being an indicator of velocity and brisance that is regarded correctly in my opinion as more important as a parameter of performance for a detonator than is the total explosive strength of a detonator as would be gauged by its more general blast effect crushing pea gravel to sand. The plate test shows the contact effect in the near region to the detonator and the violence of impact directed upon the target material in immediate contact, rather than the more distant sphere of total "bubble energy" as would be applied at greater distance and captured as work done crushing gravel to sand. It compares with the greater heaving effect of low velocity cratering charges which have more total energy to do work as compared with the sharper effect of a higher velocity energetic like would be used in contact as a steel cutting charge. The sharper effect and local effect is more important for a detonator.

Attachment: Initial_priming_substances_for_high_expl.pdf (1.5MB)
This file has been downloaded 1078 times

[Edited on 9-2-2014 by Rosco Bodine]

Hennig Brand - 9-2-2014 at 10:57

Thanks for the file. As an added bonus the plate test is also very easy to perform in comparison to the sand crush test.

Attached is the description for the sand crush test method from the text "Explosives" by Meyer. It sounds like it would be a pain for the hobbyist, but it could be done.

Attachment: Sand Crush Test Description from Meyer.pdf (115kB)
This file has been downloaded 1050 times

[Edited on 9-2-2014 by Hennig Brand]

Rosco Bodine - 9-2-2014 at 11:00

Yeah the plate test won't lie to you about what you have. If you are blowing a nice hole and you get that signature radial pattern surface spray of particle impacts, you have got what you want to see.

Here is more about the sand test
http://www.sciencemadness.org/talk/viewthread.php?tid=389&am...

The sand test for determining the strength of detonators
Christian George Storm and Willard C. Cope 1916

file download available here

http://sciencemadness.org/scipics/The_sand_test_for_determin...

[Edited on 9-2-2014 by Rosco Bodine]

roXefeller - 9-2-2014 at 15:05

Ral123, using a hammer might be unsafe, but it also doesn't make technical sense. First, we are trying to gauge variability in cap manufacture to reach reliability. The hammer strike can have tremendous variability. Worse still, you are right, it could dead press the cap. Most of Hennig Brand's successes came after he pressed the DDNP to the optimum pressure (not the extreme). You'll get reliability by doing likewise. As far as rearranging, that isn't necessary. The graph here (https://www.sciencemadness.org/whisper/viewthread.php?tid=43...) shows that optimum loading density is better than rearranging the particles to improve the packing density. Once optimum is reached, increased density has large performance drops (a greater minimum quantity). Anyway, Rosco has a better suggestion for improved rearrangement, incremental loading and pressing. Loading the whole shot and pressing it leaves the deeper material unpressed because of the non-newtonian aspect of the particles. The material will distribute the pressing load along the angle of repose to the case sidewalls, at an angle away from the case axis, not parallel with the case axis. So at a distance of half to a whole diameter into the material, the powder will begin to experience progressively less pressure, depending on friction and pressure. Incremental pressing will permit each increment to feel the pressure uniformly. As example, 0.1 gram is loaded and pressed, then another 0.1 gram loaded and pressed, and a final 0.1 gram loaded and pressed, totaling 0.3 grams. A refinement of that is to gradually progress to light pressure as more is loaded, the last one being nearly loose. This is the opposite of the once pressed method where the top portion is packed more and the deepest portion is least packed. Loose packing on top improves flame sensitivity. I apologize if any of this is already common knowledge to you.

Hennig Brand - 9-2-2014 at 16:48

Though it wasn't stated, I was of course using incremental loading for all of the tests. The density issue is significant with DDNP, but initially I just wasn't using enough primary either. Although I haven't tested it thoroughly myself, the literature indicates the added confinement from the reinforcing cap does a lot to improve the efficiency of DDT type primary explosives in particular.

It is true that a press gives one much greater control of loading pressure/density. I was looking for an arbor press a while back, but instead made due with a mostly cost free homemade lever press.

roXefeller - 9-2-2014 at 19:28

Quote: Originally posted by Rosco Bodine

Yeah the plate test won't lie to you about what you have. If you are blowing a nice hole and you get that signature radial pattern surface spray of particle impacts, you have got what you want to see.
[Edited on 9-2-2014 by Rosco Bodine]

How would the plate test appear for less brisant explosives intended for uplifting power, like mining compositions? Would the radius of the hole be less defined and more bowl shaped? More torn than atomized? Maybe Hennig can grab some borehole dynamite and show us in pictures.

Hennig Brand - 9-2-2014 at 20:05

I haven't done a lot of testing of this but the more brisant explosives, like picric acid, tend to make and propel shrapnel and shatter and cut even steel. Less brisant explosives need confinement to be efficient. The less brisant explosives can bend and tear steel if enough is used, but it's not the same shattering effect as with brisant explosives. I don't think there are too many blasting agents or dynamites that would work at a 7.6mm diameter either. The first chapters of many explosives texts will explain this better than I just did.

Dornier 335A - 9-2-2014 at 23:50

Quote: Originally posted by roXefeller

If the plate isn't pierced, more brisant explosives tend to give deeper dents while more powerful and less brisant give wider and shallower dents.
I normally use aluminium plates for plate tests and when they are pierced, rounder holes indicate higher brisance. Shattering too of course. I could upload some pictures later if you want.

Ral123 - 10-2-2014 at 14:03

Tanks for the info, I didn't know exactly what the sand crush test is, but it makes a lot of sense now.
I absolutely agree that pressing is the way to obtain consistency in the density when different setups are used. But I'll still respect poor man's way of achieving density and liquid/cast materials.

roXefeller - 10-2-2014 at 20:43

"Success Initiating Picric Acid at 0.76mm id with 0.7g of DDNP"

Looking through the Matyas text (Fig 2.12), an improvement in efficiency might be expected when you are using that reinforcement cap. It seems that 0.7g is still in the very reliable range, not near the minimum. I know Rosco will say that the same reduction isn't to be expected and needs to be implemented into your own trials, but it suggests something in the direction of goodness.

Rosco Bodine - 10-2-2014 at 22:47

It cannot be ruled out that from time to time academics have an eccentric gift for bullshitting and hyperbole and exaggeration about energetic materials, and maybe a few other things, which as a consequence leaves less eccentric more pragmatic experimenters who have a less psychopathological sense of humor to do honest tests find out what the real data, the no bullshit data, should read. Maybe the old scientists have suffered too much toxification of the brain from long exposure to heavy metals or the cocktail of vapors in the laboratory perhaps further aggravating whatever science? affected or broader, deeper madness may have been innate as an aspect of their general personality or personality disorder, such as the case may be. Maybe they are overmedicated or undermedicated and ever searching for level flight. Mad scientist is a cliche, but most cliches have a grain a truth that has made the cliche have traction enough to become a cliche for enduring. Consider the source and subject the data to verification.

Hennig Brand - 11-2-2014 at 05:38

Like Rosco said before, the general principles from the literature are generally more or less correct and serve as a very useful guide. However, the literature can also be a big hindrance too because people generally put a lot of stock in the literature values and don't realize that those values are very often not going to transfer well over into their own real world tests. A lot of my problems have come from trying to square what was going on in my own experiments with what I had read from the literature. This was continually causing me to doubt my own results and what I was actually seeing in a real life test.

Just from the few experiments I have done, I would now say that using a whole gram of DDNP to initiate picric acid in the configuration above would not be a waste (for the hobbyist). The added reliability granted by this excess is well worth it.

Rosco Bodine - 11-2-2014 at 09:30

The scientific peer reviewed literature is not the gospel, and it will be found to be seasoned with opinion and faulty conclusions and fish stories presented under a pretense of "scientific accuracy" which results in the blind acceptance by many of "facts" that are not facts at all. Even with regards to scientific literature the reader should maintain a healthy reserve of skepticism and subject what is reported to verification, because what is the "conventional wisdom" attributed to what is "truth" may be very different from what is a
verified and confirmed truth known with certainty to be fact. At this forum and many others people will speak "authoritatively" without referencing sources and without referencing confirmations of sources as if they speak certain knowledge while they are only regurgitating incorrect data previously diseminated by others. Scientific discussions are replete with this kind of thing where people are simply operating on "faith and belief" that what has been written by others is correct. But what has been written by others and repeated by still others may not be correct at all, no matter how large may be the concensus of true believers, who don't even know themselves what is occurring is only a furtherance of "conventional wisdom" that may not be actual knowledge at all, when put to the test. Once put to the test, the matter is settled business.

Benjamin Disraeli - There are three kinds of lies -
lies, damned lies, and statistics.

Thomas Huxley - There are three classes of witnesses -
liars, damned liars, and experts.

<iframe sandbox width="640" height="480" src="//www.youtube.com/embed/bynFnXYbgFw?rel=0" frameborder="0" allowfullscreen></iframe>

[Edited on 11-2-2014 by Rosco Bodine]

roXefeller - 11-2-2014 at 15:30

Amen, Reverend Bodine. If only I could get my colleagues to be skeptics in search of the truth of matters.

Rosco Bodine - 11-2-2014 at 18:58

Uh huh. Our fellow Hennig Brand is presently having a "Zen moment" regarding the objectivity and trustworthiness of the scientific literature. Don't be afraid to strike through the errors and write corrections in the margins of your college textbooks, including history books. Don't be afraid to see what is true even when others tell you not to believe your lying eyes..... but instead believe what they tell you. Believe your own findings. Life is short, illusions can be costly, and choices consequential, so try to learn and know well what is true even if you have to find it and define it for yourself sometimes, and choose wisely based upon what things you are reasonably certain. And it never hurt anyone to pray they will get it right or got it right. There is an old NASA joke about the shepherds prayer, attributed to the early astronaut Alan Shepard .....
Dear Lord, don't let me f%#k up !

http://en.wikipedia.org/wiki/Alan_Shepard

Deliberately published disinformation can seem convincing and persuasive as authentic. And it can be quite a startling revelation to the discoverer who has found and identified some of it, evidently provided complements of your own government or that of another country. Surely there must be a reason for such disinformation. And it is not difficult to figure out the sensitive nature of the subject matter may lend itself to disinformation being likely for something like DDNP.

How much more disinformation about how many different topics is out there, and how much disinformation has become believed and accepted as conventional wisdom?

DDNP disinformation is just the tip of the iceberg.

[Edited on 12-2-2014 by Rosco Bodine]

Ral123 - 11-2-2014 at 22:31

I'm not too sure what is the disinformation about DDNP? We all know it's generally in the same category as HMTD, rather then azide. I've read a material that lead or silver azides are unbeatable by any environmentally friendly material with similar price and are the only way where reliability matters. DDNP should have similar energy to AP by weight and be far from the energy of for example Tetryl.

Rosco Bodine - 11-2-2014 at 23:07

My cynicism and skepticism is magnified because even 10 years ago I had already concluded that much of the literature description about not only DDNP but about HMTD as well was pure bullshit. Take that literature with a very large grain of salt.

Hennig Brand - 12-2-2014 at 05:46

The title above, "Success Initiating Picric Acid at 0.76mm id with 0.7g of DDNP" should of course have had 7.6mm in the title not 0.76mm. Focused on other things I guess.

[Edited on 13-2-2014 by Hennig Brand]

Rosco Bodine - 12-2-2014 at 06:16

Quote: Originally posted by Hennig Brand

I do understand the concept and you have worded it well. I don't know how to quantify it exactly at the moment, but DDNP seems to be somewhere half way between lead azide and lead styphnate in terms of unequivocality. I would really like to know how the military and industrial people design their DDNP caps.

According to TM 9-1300-214 “Military Explosives”, “an unconfined sample (of DDNP) burns with a flash if ignited but even the slightest confinement causes a transition from burning to detonation. A charge of DDNP undergoes detonation when ignited if pressed into a blasting cap shell with a reinforcing cap and a piece of black powder safety fuse crimped in the shell. A spark falling into the open end of such a blasting cap causes only ignition and flashing of the DDNP.”

Those caps I made, from the above picture, were only sealed with a bit of hot melt glue at the fuse end and the cap was not reinforced. I think I can come up with something much better. I haven’t given up on DDNP yet.

Also from “Military Explosives”, “the sand test indicates DDNP is a better initiator of detonation than mercury fulminate or lead azide for less sensitive high explosives. The most marked evidence of this is the ability of DDNP to initiate the detonation of ammonium picrate and cast TNT. For initiation of more sensitive high explosives, DDNP is not superior to lead azide.”

Also from “Military Explosives”, “when subjected to the sand test with ignition by a black powder fuse, the brisance of normal lead styphnate (10.5 grams of sand crushed) is much less than that of lead azide (16.7 grams of sand crushed). “ The grade of DDNP used for military purposes, specs taken from the same text, shall crush not less than 33 grams of sand in the sand test.

The more I read about it, DDNP sounds like it would be a great initiator for picric acid and other insensitive secondary explosives.

BTW, that Chinese primary explosive presentation, linked to in the "picramic acid from picric" thread, suggested 6mm casings be used for DDNP. It looked like 6mm was recommended for all the primary explosive examples, but it still says something about suitable casing diameters for DDNP (I think).

[Edited on 31-1-2014 by Hennig Brand]

Lets take a look at TM 9-1300-214 “Military Explosives”, which you reference, now attached. I took a brief look at this text which appears to be a pretty good presentation as military manuals go, and I have seen this one before but it has been some years ago, and I may even have the actual hard copy manual. Anyway, just looking at the manual for 5 minutes I found an error on page 7-11 in the fourth line from the end of the page of the government production where the quantity of lead azide given is plainly erroneous and would be immediately recognized as erroneous by any knowledgeable person who may have been proofreading that text which is probably still taught every day as an authoritative reference textbook. The book is WRONG right there where I say it is and that FACT can be confirmed very easily by anyone testing the matter. So you really have to be careful about just accepting "what is written" in what may even appear to be "no bullshit" publications because it may just happen that what you are reading and swallowing hook line and sinker is pure bullshit. There is so much of this kind of stuff found in the literature that it is impossible to believe it is simply inadvertent error or misprint. It is on a scale that speaks of deliberate disinformation that someone in authority has decided is propaganda needed for whatever reason. What does it make me that I am not deceived?

In an entirely different orbit from the target audience of such nonsense.

Attachment: TM-9-1300-214-Military-Explosives.pdf (1.9MB)
This file has been downloaded 1291 times

Update: These figures including the erroneous figure for lead azide looked familiar to me and this does appear to be a transcription error for tabular values which originally appeared in a German journal article circa 1939 by Wallbaum and is cited correctly by Davis on page 441 of COPAE, but the figure for lead azide has been quoted incorrectly off by a decimal place, which is a common error that I have seen before. The figure given in the military manual is wrong by a multiple of 10 due to the incorrect decimal place. Sloppy editing could account for this error instead of it being deliberate disinformation. Or the appearance of such a simple explanation to account for such an error could be an aspect of plausible deniability about propaganda, or a deliberate test to see which student would distinguish themself for taking notice and identifying the error in the textbook. The idea of such an error being a "test" seems
most likely. Sometimes there are errors deliberately placed in textbooks and lectures to identify which students will show aptitude by making note of the errors and taking exception with the textbook and/or the teacher.

A case in point example is provided that if tabular values appear possible to be incorrect by a full order of magnitude, then it is entirely possible the decimal place for the published value is wrong, but the resulting numerical value is correct when the decimal error is fixed.

Setting aside the distraction caused by making note of this error there is an item of interest on page 7-13 paragraph f
regarding the sand test for lead styphnate responding to ignition by fuse as compared with lead azide. What would be interesting as a test not reported is to combine the two separate tests with the same quantity lead styphnate having the lead azide superimposed and the lead azide initiated by fuse. It is predicted that the combined output would be much greater than the numerical sum for the sand crushed by the separate tests simply added together. However the ultimate power of lead styphnate is explained
using a different example which shows that lead styphnate has more than double the output when it is initiated by lead azide, and that under high order detonation conditions then the output power of lead styphnate exceeds the power of either lead azide or mercury fulminate mixtures. This illustrates a very important point about the DDT property
of primary and secondary explosives which shows the sudden increase in output power that is realized for the same energetic material at the transition from low order to high order detonation.

A followup that would seem needed is to here make note this is why a binary mixture of lead azide and lead styphnate shows a synergistic effect where the unequivocal primary explosive lead azide functions as a homogenous booster and initiator for the lead styphnate when there is a binary mixture of the two materials, usually with the smaller particle lead azide being the matrix with the larger lead styphnate crystals being the aggregate, the combined composite has a greater output power than either material alone. The same principle of synergy applies to many other composite explosives that function best as binary or multiple mixtures and can also apply for clathrates or double salts.

[Edited on 12-2-2014 by Rosco Bodine]

Hennig Brand - 12-2-2014 at 09:19

Yes, that is an obvious error on page 7-11. I don't know for sure, but I think you would not be paranoid at all in thinking that information was censored and also that there was a high probability that disinformation was used as well. That mistake in 7-11 is maybe not a good example of that, just because it is such an obvious mistake, but then again I have a lot of knowledge now about the subject matter that most people wouldn't have. Maybe, it's not a bad example after all.

Mixtures of "unequivocal" and DDT type explosives, and the synergistic effects, are very interesting. I will probably start looking into them more in the future.

Ral123 - 12-2-2014 at 10:45

The book on azide:
Storage at 80°C for 15
months caused no decrease in brisance and, after such
storage, a priming composition containing lead azide
showed no decrease in sensitivity to stab action. The
beta form is considerably less stable than the alpha form
and undergoes decomposition much more rapidly.
I'm kinda confused now, how do you get rid of the beta form?

Here's the book on fulminate:
Storage Time required to reduce purity to 95%(near worthless according to the book)
temperature
80C - 0.5days/
50C - 8 months/
30C-1.7 years/
20C- 7 years/
10C - 8 years
From what I've heard it stores barely 6 months at slightly warmer then room temperature. What's the first question-how will the decomposition products react the the Al/copper case and the base charge(MHN for example)

Rosco Bodine - 12-2-2014 at 10:47

The error of a decimal place has been something I believe is common based on reviews of the literature. You are correct the average reader would have no basis to know any better and would simply trust the information. That could apply to 999 out of 1000 students who won't rock the boat. I am the odd man out exception on that, so the error jumps right off the page at me, and I would take the red marker to it right there in class as I was raising my hand to make the announcement about errata that got past the proofreaders, or if it is a test put there deliberately to see who is sleeping in class then I'm answering that roll call with a shout announcing I'm not asleep or just another unit being programmed with false information that goes right over my head. I get it.

Yeah the behavior of synergistic mixtures, double salts, clathrates, ect. is an intriguing subject as topic of study by itself. It is also a means of achieving better economy for example with silver azide which is quite chemically stable and is an excellent initiator but will be expensive due to the "burning up of silver" which is basically burning up money that is inherent to its use. If for example a mixture with lead styphnate 60% and silver azide 40% it is found the initiating ability is equivalent similarly as is true for lead azide, then there is found a means of stretching ones dollar by the "cut" of the more expensive material using the lead styphnate or possibly another even cheaper component. Such mixtures may even have superior performance without regard to the increased economy which then comes as a bonus.

roXefeller - 12-2-2014 at 15:14

Um, does anyone see the irony of Hennig Brand copping to his decimal point error of 0.76mm. Yet we all knew what he meant. Were you just spreading disinformation?

Hennig Brand - 12-2-2014 at 15:54

Ha! I thought someone might say that after the last few posts. Given my pay grade I should be entitled to a few more slips now and then, don't you think?

Also, I was very quick to point out the mistake. Sometimes mistakes may just be mistakes I'll give you that.

roXefeller - 12-2-2014 at 17:35

There wasn't anything quick about it. I've been ignoring it since Feb 3rd when you first slipped up. I wasn't going to poison the well of good conversation with a dumb response.

Hennig Brand - 12-2-2014 at 18:05

I didn't realize I did that way back there also. Must have been thinking cm and wrote mm or something. Like you say, it was pretty obvious anyway. What do you mean there wasn't anything quick about it? Getting a correction done to any sort of published material in nine days would be light speed I would imagine.

Thanks for pointing that out. It is a bit unprofessional and generally I try to avoid making those types of errors, but it happens.

[Edited on 13-2-2014 by Hennig Brand]

Bert - 20-2-2014 at 20:31

I spent a few minutes yesterday talking with an SFX guy who was also a chemical engineer, and had been in charge of product development for a company that made bullet hits, among other things. And he had personally made and used DDNP for bullet hits.

I am curious after our conversation. Has anyone had an accidental explosion while working with DDNP, either in production or use? Or know of any documented industrial accidents? He seemed to think of it the way I think of organic peroxides- Bride of Satan, etc.

Hennig Brand - 21-2-2014 at 04:39

From the few things I have read it has, in most cases, significantly less sensitivity than the other commonly used primaries. It is very sensitive to flame, but impact and friction sensitivity are less than most others. It is of course still a primary explosive and in relation to a secondary explosive is extremely sensitive. It really depends on how you are making your comparisons I think. I have only worked with the material for a matter of weeks, so obviously I am not the expert.

Ral123 - 21-2-2014 at 10:32

But you still suggest a booster made of it, mixed with TNP. I've always loved exotics.

roXefeller - 21-2-2014 at 12:46

It wasn't really a booster, so much as a compound cap with TNP as the base. The booster would be like 50g of PETN, RDX or dynamite, or whatever other lower sensitivity material to detonate something more insenstive like ANFO or cast TNT (or maybe melamine dinitrate, yeah I'm still pondering it

). The cap is inserted into the booster and the booster inserted into the real base charge. It's a big difference because nobody is advocating using 50g DDNP to set off anything. Just the one gram necessary for the TNP.

Ral123 - 21-2-2014 at 14:09

Who would waste such fine exotic materials for dynamites and anfo?

Hennig Brand - 21-2-2014 at 17:03

Quote: Originally posted by Ral123

But you still suggest a booster made of it, mixed with TNP. I've always loved exotics.

Many things were considered during some of the brainstorming sessions. I wouldn't say that it was an awful idea, but there are probably better ones.

Dynamites in general are more easily initiated than TNP. For instance, 0.5g of MF or TATP will easily set of nitrate dynamites with only 15-20% nitroglycerine. The older literature states that Picric acid can be reliably detonated with 1g of mercury fulminate, though I have never tried it. In my tests 1g of TATP failed to detonate very pure picric acid (>98% pure). The difference in sensitive is even greater than it looks, because MF and TATP are DDT type primaries which means that a significant amount of the primary charges would be burned up before they got up to the high velocity needed to be effective initiators.

Ral123 - 21-2-2014 at 23:14

According to a book, cap No1 can set off efficiently 75% ghur dynamite, but for pure NG you need cap No8 or cap No1 and thick glass confinement.
For me it is a mystery why maximum density 30% NG, 70% crap can go off readily but pure maximum density mixtures(cast ETN, NG/PETN, blast jelly and other) sometimes fail.

Success Initiating Picric Acid at 7.6mm Diameter with 0.50g of DDNP

Hennig Brand - 23-2-2014 at 06:56

It was such a nice morning so I decided to go for a walk in the woods. I also decided to bring a blasting cap and witness plate with me. The test was very successful, but I made the mistake of changing 2 variables at once instead of just one so more testing will need to be done in order to quantify how each variable contributed to the improved performance.

First, unlike past tests, the DDNP was purified by recrystallization. The DDNP was dissolved in acetone at room temperature (solubility ca. 6g DDNP/100g acetone) and then ice cold water was trickled in with rapid stirring. The DDNP formed was very low density, but when the sample was tilted back and forth in the light thousands of tiny crystals could be seen sparkling. A picture of the recrystallized DDNP is attached below.

While loading the detonator I got the bright idea to lock the reinforcing cap in place by pressing in a slightly oversized wooden bushing in behind it. This was the second variable. Wood in general is quite elastic, so by using an oversized section of dowel as a bushing (or plug) and using a press to press it into place it makes a very tight friction fit. A 1/8" hole was drilled axially through the center of the 5/16" dowel section to accept the fuse. A small amount (0.05-0.1g) of black powder was placed over the touch hole, on the steel reinforcing cap, before the wooden bushing was pressed into place firmly on top. Once the fuse was put in place the last 1/4" of cap casing was filled with hot melt glue.

The DDNP was weighed on digital scales accurate to 0.01g. The 0.50g of DDNP was pressed as hard as could be comfortable done by hand (without press) into the reinforcing cap. Only 1.5g of picric acid was used as in the last test. The first gram of picric acid was pressed incrementally with lever press 0.25g at a time. The last 0.5g was poured in loose and the reinforcing cap pressed in hard on top with the lever press. It was a successful detonation. A hole was blown through the 3mm witness plate, but it wasn't clean and a small film of steel was left covering much of the hole. A scab of steel was torn off the back side of the steel plate as in the earlier tests.

When purified and with strong confinement DDNP is now performing about as well as my lead azide in terms of its ability to initiate picric acid. Any more decrease in DDNP charge weight and DDNP will be outperforming my lead azide, since 0.4-0.5g is about the weight of my lead azide needed to initiate the same picric acid. I now believe that the literature may be correct and that with strong confinement DDNP can be as effective, or even more effective, for initiating insensitive secondaries like picric acid and TNT. I still believe that many of those minimum values stated in the literature are the stuff of fantasy however.

DDNP Recrystallized From Acetone.jpg - 315kB

[Edited on 24-2-2014 by Hennig Brand]

Rosco Bodine - 23-2-2014 at 09:02

When you say 7.6mm then I am understanding that to be the column diameter for the charge itself, the inside diameter of the capsule, correct? Your small refinements are working towards finding the optimum loading or "sweet spot" conditions for a design that fits well the components you are using. On an industrial research and development basis you would actually see charted differences for the results of column diameter variations of 0.1 mm increments, and variations that would attend different loading pressures or progessive incremental loading schemes, and effects related to changes of the initiator weight probably in 10-20 mg increments. So a compound detonator is a precision device exactly in the same ways as is a cartridge of ammunition.
Every little variable will come into play, and will be magnified for a sluggish or fickle about conditions material like DDNP. My lead azide even colloidal lead azide performs better than what you are seeing, because colloidal lead azide is something that I have used as a control standard for comparison with other materials. But just as results may vary across a range as reported in the literature, likewise there is a peculiar uniqueness about the combination of materials used by a particular researcher or experimenter which can produce a range of different but still believable results, so what you are seeing occur
can be "out of range" for what I have seen, yet still be perfectly valid for your configuration which is working at a different column diameter from what were my tests. You are actually using what is likely a good choice for diameter which is less demanding of precision but at some expense of economy and absolute efficiency with respect to economy as a design constraint, but the thing gained is the device will be less sensitive to tiny changes, including degradation during storage. The minimum charge that you are likely to identify at 7.6 mm will very likely be within the range of the theory I have about the effect of geometric scaling and the disagreement I have with the conventional wisdom of the "trusted" literature which I have learned to trust about as far as I can throw it, so far as a precisely literal translation of the literature goes. I would concur with your observation that the literature quotes figures that are residing in an alternate universe from what I have observed, and sometimes the generalizations made are wrong too. I think the figures are sometimes underestimating but more often are overestimating and it would seem possible that some bias may have been involved. If you compare the theoretical with the figures used that are published for some actual devices, you will see that the actual manufacturer used a whole lot more as a minimum charge in the actual device, than what may be indicated was minimum found in a research setting. There is a real difference between minimum theoretical from experiment and minimum practical for actual practice, which brings variables not counted in an experimental setting.

A suggestion I would offer for the hardwood bushing is that when the fuse is inserted through it as shown, lard the outside of the protruding fuse with epoxy, or superglue, or lacquer, and then withdraw it till nearly flush with the bushing to seal the fuse by what film of adhesive is dragged back into the bushing by the procedure. When the glue has set but not yet hardened completely the fuse may be trimmed flush with a razor. An additional refinement is to take a thread cutting die to about half to two thirds the length of the bushing and cut a thread on part of the length of the wood bushing. During assembly the smooth portion of the bushing is inserted just so far as the beginning of the thread, and the exposed thread is larded with adhesive retained in the thread and then the bushing and fuse may be inserted to full depth. The adhesive when hardened in the thread effectively locks the bushing and makes a permanent assembly, while the wood bushing itself should function as a pretty effective reenforcing cap. It is possible but unlikely that any adhesive will migrate and contact the energetic materials, but a precautionary test is a good idea to see if there are any ignition hazards where an adhesive that would be used reacts with the energetic material, just to be sure there is no issue in the event that unintended contact with an adhesive occurred. It may be found that some stock standard part stepped diameter shoulder bushings are sold as circuit board standoffs, and may serve the same purpose. I am certain I have seen such electronic parts as might be directly adaptable for such use, made from various plastic, ceramic, and metal materials. It would not be difficult to make a forming die for casting or injection forming from some plastic material such bushings if there was a need for making several, to save the trouble of turning them individually on a lathe.

In the alternative a stepped diameter bushing could be rolled from that kraft paper gummed packaging tape which must be moistened by a wet sponge to activate the adhesive, like is used to roll tubes for pyrotechnics. If the tube was rolled on a spindle full length with a few turns to form a tube less than the finished diameter, then a few more turns of a less wide strip could be added to build the diameter to what is a sliding fit for the finished part after it has dried and cured. This would provide a shouldered bushing made of paper which is actually quite strong. Alternately one continuous strip of the tape could be used having a full width portion which is wound first and steps down in width to more narrow strip wound to complete the stepped diameter tube. A few prototype strips of slightly different length could be wound to determine the dried dimensions of the parts and then the exact lengths required for each width section of the tape would be known, so that the part could be reproduced easily. Instead of an abruptly stepped diameter transition, the full width smaller finished diameter section could be wound first a few turns and then a tapered winding done simply by using a length of tape which is fixed width just long enough to make the starting turns and then tapers in width to a fixed more narrow width desired for the transition diameter of the larger diameter end.
The end result would be a cylinder having a fixed diameter bushing effect at one end for a certain length, which would taper to a smaller diameter along the further length. Adhesive could be applied to the tapered portion exposed after the cylindrical portion of the bushing is inserted. For a very viscous adhesive such a tapered bushing arrangement would work better.

[Edited on 23-2-2014 by Rosco Bodine]

roXefeller - 23-2-2014 at 11:26

So why do you think that the hole in the witness plate didn't quite come through clean? Did you use hot melt again to attach the two? You had mentioned lacquer before, yes?

Hennig Brand - 23-2-2014 at 14:35

Just added the word diameter to the above title, it was an oversight leaving it out. No, I used lacquer this time to water proof the cap end, not hot melt glue. The picric acid was initiated, but may not have been overdriven as much as when more DDNP was used. Quite a few interesting ideas Rosco. The picture of the bushing is a bit misleading. The bushing was pressed into place and then the fuse inserted before sealing the cap end with a glob of hot melt glue. The hole drilled in the bushing did match the fuse diameter almost perfectly however.

Yeah, practically a rather large excess of primary is always used I guess. I read that about 0.3g of lead azide is used in military detonators to initiate a RDX or PETN base charge (IIRC) which is a lot more than is actually needed. The inside diameter of these military caps is 1/4" IIRC. They are thinking about reliability over the long term when they load these caps. Even if the primary becomes significantly degraded after five or more years in storage they have added enough extra primary to ensure that the cap will still function properly.

I originally thought that using less DDNP was resulting in less output from the picric acid base charge. However, after closer examination of the witness plate, there is practically no difference between the tests done with 0.7g DDNP and 0.5g of DDNP initiating 1.5g of picric acid. The trial using 1g of DDNP and 2g of picric acid did produce superior results, but the extra weight of picric acid could have accounted for that. I will perform a test using 0.5g of DDNP and 2g of picric acid which should further my understanding of what is actually happening.

It is important to note that the efficiency of DDNP benefits greatly from the extra confinement provided by the reinforcing cap, whereas with lead azide the benefits from increased confinement are practically negligible in comparison. The following table taken from the Matyas text illustrates this.

Influence of Reinforcing Cap on MF, DDNP & LA.jpg - 56kB

Pictures of the top and bottom of the witness plate. The hole to the right is from the last test.

[Edited on 24-2-2014 by Hennig Brand]

Ral123 - 24-2-2014 at 10:13

I guess the DDNP is a good choice where you want to separate the primary and the base charge with a membrane or something. Then the LA won't work well in small amounts anyway so you may use DDNP.
If you make a stability test of the DDNP, that would be great. A sample of LA was left on the sun in the summer in a black container. It didn't change colour or behaviour after months of sitting there. Neither did a Tetryl sample. I wonder how would DDNP be.

Hennig Brand - 24-2-2014 at 12:26

Membrane? I haven't been using any sort of membrane.

According to the literature DDNP is quite stable; however, it is sensitive to sunlight. This is not an issue for me, since it is very easy to keep it out of the sunlight. Apparently it is mostly the surface of the DDNP particles that are altered by sunlight and this outer layer apparently protects the inner material to a high degree. I personally just keep it out of the light. I don't think DDNP is as storage stable as lead azide, but it is still pretty good.

[Edited on 24-2-2014 by Hennig Brand]

2g of Picric Acid Initiated in 7.6mm id Al Tubing by 0.50g of Hand Pressed DDNP Using Steel Reinforcing Cap

Hennig Brand - 24-2-2014 at 12:56

Because a lot of my posts are becoming very repetitive, I will simply state that this cap was loaded exactly like the last one, except that instead of 1.5g of picric acid 2g was used. The test was a success and from examining the witness plate there is very little difference between the earlier test using 1g of DDNP to initiate 2g of picric acid and this test using 0.50g of DDNP to initiate 2g of picric acid. Once DDNP reaches high velocity detonation it is a very effective primary. I would imagine that I could even go less than 0.50g of DDNP with the cap configuration and purity of DDNP I am using now. It probably wouldn't take that much more DDNP to initiate TNT, except for the fact that the base charge diameter would need to be larger. Probably could still keep the reinforcing cap id at 1/4" though.

I think the purity of my crude DDNP was a big performance issue. I also think that using the locking, tight, friction fitted bushing in behind the reinforcing cap is really improving confinement. DDNP can also easily be over pressed. Lately I have just been pressing it by hand with good results. Unlike LA, DDNP requires very strong confinement to be efficient, but if those needs are met it is in fact a very good primary.

DDNP is a demanding material and a lot more understanding is required to use it effectively and efficiently as compared to the other common primaries.

The hole on the right, in both witness plate shots, is from this test. The witness plate is the same beat up 3mm thick steel hole saw disc from the earlier tests.

I would like to thank Rosco for helping me analyse these tests so far. He saw things that I initially didn't, which comes with experience I guess.

[Edited on 24-2-2014 by Hennig Brand]

Rosco Bodine - 24-2-2014 at 23:42

You are welcome for whatever helpful information I have provided. It is really a good photo documentary and discussion that is bearing out the truth of some things I have stated from the time of the early discussions about how picric acid is really the one energetic material you want to know well, and have available if you had a choice to pick one of the many energetic materials as most useful. It is the derivatives like DDNP and related derivatives, and the 3 flash igniters that are derivatives also which makes picric acid special. Picric acid is unique in the position it occupies as an easily made energetic material having derivatives that are also useful for making a firing train, and the resulting system will be reasonably safe, and storage stable, and will be a system having significant output. There is a lot of interest in "green" technology "lead free" energetic materials also, and DDNP actually does already fit that description of being "green technology" for applications where a lead free requirement is imposed. It is likely possible to use DDNP in a synergistic mixture with a quicker unequivocal primary like silver azide or some of the green friendly tetrazole primaries, to reduce the loading requirement related to the minimum charge as would result from accellerating the DDNP with a quicker primary in a composite. The economics of such a composite would likely be commercially viable for manufacture particularly of inexpensive fuse caps. Arts and practices for expedient blasting is something that has been around for over a hundred years, but I'm not sure we should be talking about this sensitive information on the internet, since the Chinese might learn of this and become involved in manufacturing fireworks

An idea that could be worth trying regarding the recrystallization scheme and strategy of dissolving the DDNP in acetone and then adding water to the acetone dropwise.
It may be helpful to use instead of straight water a 10% to 30% water in acetone mixture that is injected through a capillary bore tubing like from a syringe pump if you have one, with the discharge tip of the capillary in the vortex current of a stirrer where the slowly discharging moist acetone is being sheared and well mixed by the current flowing past the discharge of the capillary near the stirrer bar or blade, to enable a very smooth gradient mixing to occur which should favor good crystal development in a very smooth and very gradually modified solubility system. As the solubility is being ever so slowly reduced by such technique, the crystals having time to grow should develop more fully than when a crash precipitation occurs on a huge amount of local nucleation as occurs when straight water is being dripped into the acetone. Crash precipitations favor a colloidal microcrystalline precipitate having lower density and smaller crystals. There will be found an optimum injection rate for the moist acetone. In the alternative a cosolvent non aqueous precipitation solvent could be used, like modifying the acetone solution of DDNP solubility downward by gradual addition of methanol or toluene or some other non aqueous solvent, and this could lead to even larger crystals or a different shape crystal. It is also possible to dissolve a percentage of something like a nitrated polyol like PETN in the acetone along with the DDNP and coprecipiate the composite mixture which may have improved properties.

[Edited on 25-2-2014 by Rosco Bodine]

Ral123 - 25-2-2014 at 07:35

You suggest lead picrate may be able to set off TNP? I suppose that would take quite heavy steel piping.
Hennig, in case light gets to DDNP, the outer layer will give NOx decomposition products(IMO) witch may start autocatalitic reaction in the rest of the material and reduce the potency after storage a lot. The pure N2 from lead azide can't do that.

Hennig Brand - 25-2-2014 at 13:32

Possible ways of using an unequivocal primary to get DDNP up to high velocity more quickly has been in the back of my mind lately. I am sure it can be done and in probably more than one way. The solvent evaporation method can make very nice free flowing material, but except for the improvements with regards to handling I don't think the benefits warrant the extra labour/time/expense. Rosco, your proposed method would probably make nice free flowing material also.

DDNP is certainly a lot greener than most primaries for sure. However, apparently on the large scale the waste streams from DDNP production are quite large and are none too good for aquatic life and terrestrial wildlife, etc.

Lead azide is certainly easier to use, but the fact that DDNP can be made from picric acid and works as well as it does makes me very happy.

@Ral123
If DDNP is sealed in an aluminum detonator casing I don't think light is an issue. Rosco has gone over the lead picrate detonating picric acid thing many times. It most likely can detonate picric acid, but it would take a very impractically large amount. Lead picrate is not DDNP.

[Edited on 26-2-2014 by Hennig Brand]

2g of Picric Acid Initiated in 7.6mm id Al Tubing by 0.40g of Hand Pressed DDNP Using Steel Reinforcing Cap

Hennig Brand - 9-3-2014 at 05:24

Another test was performed. Everything was done the same as the last test except that 0.40g of DDNP was used. All materials used were identical to the last test. As you can see from the pictures going from 0.50g to 0.40g of DDNP has resulted in severely diminished output from the 2g picric acid base charge even though it was completely detonated. The hole in the witness plate, for this test, looks very close to the holes produced in the tests where 1.5g of picric acid and more DDNP was used.

I am still not happy with how well the reinforcing cap is locked into place. I like Rosco's idea of cutting a few threads in the upper section of the wooden locking bushing and putting some adhesive in those threads before pressing the bushing into place. This method would result in a much more secure reinforcing cap.

In this configuration 0.40g of DDNP will detonate my picric acid (purity over 98% by melting point), but is not driving it hard enough resulting in diminished base charge output.

I have included a few pictures of the test. The hole on the right, in the witness plate shots, is from this test.

[Edited on 9-3-2014 by Hennig Brand]

Explosives by Marshall 1915

Rosco Bodine - 9-3-2014 at 10:57

Attached is a file of interest which describes some of the aspects of basic principles that are involved with explosives and are readily observed on the smaller scale with primary explosives used as initiators. This morning I had typed a comprehensive post on the subject but it disappeared when I attempted to submit the message, evidently a forum software glitch that also logged me out. I will attempt later to recompose my earlier attempted reply.

Attachment: Pages from Explosives by Arthur Marshall 1915.pdf (595kB)
This file has been downloaded 720 times

Sensitiveness to Detonation of TNT and Tetryl

Rosco Bodine - 10-3-2014 at 11:33

Attached is a very interesting article, which contains information explaining the reputation of tetryl for being the ideal base charge for a compound detonator. Tetryl would probably function well also as an intermediate component in a firing train.

Sensitiveness to Detonation of TNT and Tetryl by Taylor and Cope

attached

Attachment: Sensitiveness to detonation of trinitrotoluene and tetranitromethylanilin - Taylor and Cope.pdf (583kB)
This file has been downloaded 915 times

[Edited on 10-3-2014 by Rosco Bodine]

Hennig Brand - 10-3-2014 at 13:24

Those are some great pieces of reading. I have skimmed through, but will read them through more carefully when I have more time. As an explosive tetryl sounds great, but it is apparently very carcinogenic. I notice that it is often stated, in the old literature, that it doesn't take much, or sometimes any, more mercury fulminate to initiate TNT than it takes to initiate picric acid. I also notice that except for the storage stability problems, at higher temperature and/or elevated humidity, mercury fulminate can be a fairly effective initiator. Like DDNP, mercury fulminate does require confinement, however, and according to the Matyas text crystal size is also quite important in the case of mercury fulminate.

[Edited on 10-3-2014 by Hennig Brand]

Rosco Bodine - 10-3-2014 at 14:47

What is interesting to me is there is a chemical aspect to initiation which will cause a particular initiator to work especially well in combination with a particular secondary, and that chemical match can even over rule what may be expected based purely upon the brisance or strength of the initiator.

For example with lead azide it takes about 20% less to initiate styphnic acid than picric acid as would be expected based upon lead azide being the constant and the base charge sensitivity relationship. But that is reverse to what is reported when silver azide is used because for some reason styphnic acid is not more sensitive to initiation by silver azide than is pcric acid. Thus the chemical component or some unidentified aspect causes the result to be opposite what would be expected from experience with use of lead azide.

And for tetryl it is reported that even as little as 1 mg lead azide will initiate tetryl sometimes and 10 mg is certain to initiate tetryl. This shows an extraordinary example of how a particular initiator is excellent for use with a particular secondary because of some chemical and / or physical matchup.

It makes me wonder if there is a "special case" matchup for a particular pairing of less quickly accellerating initiators like DDNP, is there some particular choice of base charge which pairs best with DDNP so that a lower minimum amount of DDNP is required, or is the peculiarity of sensitivity of tetryl and lead azide something that only occurs for the more instantaneous initiators like lead azide.

Hennig Brand - 10-3-2014 at 19:16

It is interesting how the effectiveness of a particular primary can vary greatly relative to others depending on which secondary is being initiated.

DDNP is reported, in "Military Explosives" and several other references I have seen, as being very well matched to picric acid and TNT among others. The text "Military Explosives" states that it is superior to lead azide for initiating picric acid and TNT, IIRC. I bet if some threads were put on the locking bushing, and some epoxy was smeared on those threads before pressing the bushing into place, we would see even greater picric acid initiating ability from the DDNP.

Rosco Bodine - 11-3-2014 at 09:16

I suspect there is a binary mixture or a coprecipitate of DDNP which will improve its accelleration considerably and allow its strength to make a better showing, that it can be accellerated in a synergistic mixture similarly as can other initiators which have strength but are deficient in self accelleration rapidity such as is lead styphnate for one example. The classic example is tetracene mixed with nitromannite, where tetracene is a weak initiator and nitromannite is not strictly an initiator at all, but the mixture of the two is reportedly a powerful initiator. I believe there are many potential synergistic mixtures possible which are an unexplored potential for experimentation. Some of these mixtures could be "green" friendly technology so it is likely that experiments will be conducted to attempt to identify likely candidate mixtures. Similarly it could happen that the styphnic acid analogue of DDNP or one of its salts might be worth experimentation in combination with DDNP.

One of the materials which might be interesting as part of a binary mixture is N-Nitro-N-methylhydroxyacetamide Nitrate
http://www.sciencemadness.org/talk/viewthread.php?tid=18243&...

[Edited on 11-3-2014 by Rosco Bodine]

Rosco Bodine - 11-3-2014 at 14:07

I don't know what is the compatibility issue which may be there or how significant it may be. There is reportedly a measurable long term storage degradation issue also for mixtures of lead azide and lead styphnate but the mixtures are used anyway because the performance gain exceeds the loss for whatever the perfectionist may find would be most desirable in terms of perfect long term storage compatibility. For example suppose there is a 10% reduction in the average shelf life at 90+% humidity and 40C storage conditions for 20 years for the "imperfect" mixture, but the cost performance is increased 40% and actual initiating strength output increased by 25% by using the mixture that is less than perfect. The bean counters can sort out the better bargain based upon the practical aspects of their "climate change" modeling based on who is paying for the perfection and how much they have to spend. It becomes a beauty is in the eye of the beholder scenario where economic practicality is governing for the free enterprise product that will be mass produced. If lead azide and lead styphnate mixtures are in practical use for example, as they are, then silver azide substituted for lead azide should probably work equally well IMO and likewise should work with DDNP. DDNP can actually be melt cast as a binary melt with picric acid, so the DDNP is fairly chemically stable. The limiting factor there for a mixture of DDNP with an azide would likely then be the particular azide chosen, and silver azide is much more chemically stable than lead azide. So then silver azide would be the more promising candidate IMO for a mixture with DDNP.

Hennig Brand - 12-3-2014 at 07:06

Thanks for the answer. I guess you must have seen my question from my last post before I deleted the post. I deleted it because I thought maybe we had already covered that ground, but you did in fact know more than what was mentioned earlier in the thread. I am going over ways that a small charge of lead azide could be isolated from the DDNP in the cap casing but still give the DDNP the quick snap it needs to get up to high velocity more quickly. I have a couple of ideas and if I get time in the next little while results will be posted.

For me, a lot of the appeal of the DDNP & picric acid blasting cap is that DDNP is made from picric acid. The raw materials are readily available and both explosives are relatively insensitive when compared to other explosives in their respective groups (primary & secondary explosives). If I was to start adding azide to these caps I just might not feel the same about them.

I have a feeling a little extra confinement might allow dropping the DDNP initiator weight per cap even more. It is next on my list of things to test.

Rosco Bodine - 12-3-2014 at 08:23

Silver Azide has been tested in mixture with DDNP and no decomposition issue was noted and that potential issue is definitely something that the tests would have been monitoring. So here is a pretty good indication that silver azide is compatible with DDNP. And there is an old patent GB333534 that describes lead azide mixtures with DDNP and there is no note of any compatibility issue there either. What may be the result of long term storage studies for adverse conditions of high humidity and temperature is another matter, but for the first impression based on the limited information it would appear the mixtures are compatible. Silver azide is intriguing because of its chemical and thermal stability, and because its low solubility makes possible simplified synthesis which has been however inadequately described in the English language literature.
It has been my thought that silver azide first obtained as the colloidal form gotten directly from the simplified method like the Hodgkinson patents or the method of Angeli which have been further refined by the Russians, but for which we do not have a translation yet, could be filtered out and redissolved in warm ammonia solution, and slowly precipitated to the high density form using the patent methods of Costain or the British ordnance variations, or the Australian method described in the attached article.

Simplifying azide synthesis using aqueous reaction systems and hydrazine sulfate as a starting material has been one of my quests for a long time. But my time for experiments has never been available to really pursue this interest as I would prefer.

The styphnic acid gel formation that occurs as an intermediate in some synthetic methods for lead styphnate would seem like an opportune point for incorporation of silver azide as an added solid phase of the colloidal form or slightly larger particle form of some size found optimal, with continuation of the lead styphnate synthesis in hopes that the lead styphnate crystals which form rapidly from the collapsing gel would nucleate and precipitate as a physically inseparable initimate mixture which is believed would have the same synergistic effect as occurs with mixtures of lead azide with lead styphnate. But the silver azide analogue would be expected to be more powerful and have greater storage stability. The lack of stab sensitivity issue for neat silver azide would likely be resolved also by the mixture.

And it is possible there could be a ternary mixture with DDNP gotten by suspension of particles of the silver azide / lead styphnate composite in a warm acetone solution of DDNP,
with slow precipitation of the DDNP as an encapsulation of the particles to produce something like a ball powder form of DDNP having an interesting core material for every little sphere.

Attachment: GB333534 DDNP lead azide mixture .pdf (130kB)
This file has been downloaded 649 times

Attachment: Sensitization of High Density Silver Azide to Stab Inititiation ADA132994.pdf (1MB)
This file has been downloaded 830 times

Attachment: Azide Pages from Thorpe A_dictionary_of_applied_chemistry.pdf (327kB)
This file has been downloaded 852 times

Hennig Brand - 12-3-2014 at 14:28

That patent sure seems to indicate that there would be no problem mixing DDNP and lead azide. It also states that DDNP is resistant to moisture, meaning that it can still be easily lit and function properly even under high atmospheric humidity conditions. Resistance to moisture is another virtue for the list.

From the text “Primary Explosives” by Matyas,

“A technologically interesting way of preparing silver azide is based on mixing a solution of sodium azide with some explosive (MF, tetryl, TNT, picric acid, etc.) before adding silver nitrate. Silver azide then forms a thin film on the surface of the added substance.

The initiating efficiency of the mixture of MF with approximately 3-5% of SA is several times higher than for pure MF and practically the same as for pure SA.”

I am really enjoying that book.

Even just putting 0.05 or 0.1g of silver azide on top of the DDNP charge in the cap should get the DDNP up to high velocity quickly I would imagine. The contact between the two would only be at the boundary then, though it sounds like they are quite compatible anyway. It would also be a simpler process to just press a little SA on top of the DDNP as the cap was being loaded.

I used up all my silver azide, to initiate dynamite for blasting rocks this past summer, so I will need to make more. I was under the false impression that it was much less stable than lead azide. A false assumption made while observing how extremely sensitive to light it is.

[Edited on 12-3-2014 by Hennig Brand]

Rosco Bodine - 12-3-2014 at 16:15

Interesting how the data for tetryl charted in the Matayas book and imported from Grant and Tiffany is at considerable variance, like an order of magnitude with the Taylor and Cope reported data. It becomes confusing when it becomes clear that the data is conflicting, or the measurement criteria is different for what exactly is "minimum". It may depend on what your definition of "is" is.

[Edited on 13-3-2014 by Rosco Bodine]

Hennig Brand - 12-3-2014 at 17:10

Without knowing exact details of how the tests were performed it is very hard to make meaningful comparisons, this is true. An experimenter really does have to do their own testing a lot of the time.

Rosco Bodine - 12-3-2014 at 20:32

Maybe for government financed research getting data correct within one or two orders of magnitude is close enough for government work.

2g of Picric Acid Initiated in 7.6mm id Al Tubing by 0.40g of Hand Pressed DDNP Using Steel Reinforcing Cap

Hennig Brand - 13-3-2014 at 11:18

This cap was loaded with the same materials as was used for the last test. The only difference between this test and the last was that a slightly longer casing was used to accommodate a slightly longer wooden bushing and that bushing had annular adhesive grooves ground into its upper section. I forgot to take a picture of the bushing but have included a software sketch of an idealized representation. The bushing was 5/16" in diameter and there were 5 or 6 annular rings which were about 0.5-1mm deep, about 1mm wide and spaced about 1 mm apart. A 1/8" hole was drilled through from end to end, as before, to accept the core burning fuse.

Five minute epoxy was used as the adhesive. It was smeared on the bushing in and over the grooves and then the bushing was pressed in on top of the steel reinforcing cap. The epoxy was only given 1 hour at room temperature to cure which is not enough time to reach full strength (16 hours for full strength stated on several data sheets). I believe most of the strength was obtained from the 1 hour curing time however.

The test was a success. The 0.40g of DDNP detonated the 2g of picric acid and produced results very similar to the other tests were more DDNP was used. The hole was well formed and of the same diameter as the other successful tests.

The scab on the bottom side of the witness plate was smaller and the hole was the most well formed of all the tests. I believe this was because I accidently pressed the bottom gram or so of picric acid a bit harder than usual which would have resulted in higher velocity and higher pressure from the detonation.

I wonder if I could get the same kind of results using only 0.30g of DDNP if enough confinement was used.

The hole on the right, in the witness plate shots, is from this test.

Reinforcing Bushing With Adhesive Grooves.jpg - 25kB

Cap In Position On Witness Plate.jpg - 324kB

[Edited on 13-3-2014 by Hennig Brand]

dave321 - 14-3-2014 at 11:03

what this thread needs now, is a summarised process to say produce 2g ddnp
specifying amounts, and alternative amounts of other reducers for example
along with conditions.

tech sod.sulphide vs diy sod hydroxide/ sulphur

it really would be useful instead of reading 7 pages of different processes etc

users who have succeeded in the prep could help others out a lot with this approach

.....a definitive prep that works.

roXefeller - 14-3-2014 at 12:48

But that would be spoonfeeding, and besides, plenty more is learned from reading his process.

To tell the truth, I didn't believe that the bushing was to blame for the low efficiency before. But you seem to have proven your hypothesis. Do you think that picric acid is as good a booster as any as far as having power to kick off the next material? Yeah it doesn't have the sensitivity of tetryl. But it has about the same power as TNT.

Hennig Brand - 14-3-2014 at 13:30

Quote: Originally posted by dave321

what this thread needs now, is a summarised process to say produce 2g ddnp
specifying amounts, and alternative amounts of other reducers for example
along with conditions.

tech sod.sulphide vs diy sod hydroxide/ sulphur

it really would be useful instead of reading 7 pages of different processes etc

users who have succeeded in the prep could help others out a lot with this approach

.....a definitive prep that works.

I don't think I will be doing that. I take quite a bit of care to make sure that what I write is easily digestible. Most of the hard work is done for you; all you need to do is read a few pages of posts. If you are unwilling to spend a little time reading about the material you intend to experiment with, then you really have no business messing with it IMHO.

The method for DDNP from picramic acid taken from COPAE is very simple, works well and the text is free to download from this forum's library. As for picramic acid, the process is well described and even has pictures in the picramic acid from picric thread.

BTW, my processes are not optimized. On average I am only getting about 0.5g of purified DDNP from a gram of picric acid. I would imagine that there is room for a lot of improvement.

@ roXefeller
Picric acid is not nearly as powerful an explosive as, for instance, PETN or RDX, but from what I have read it is a very good initiator of other explosives. There are a lot of factors which make one explosive a good initiator of another, and picric acid apparently is a fairly efficient initiator of many secondaries.

The big thing with DDNP is confinement, but in my case purity was also an issue. When I recrystallized the crude DDNP from acetone the losses were significant. The last time, from 2.5g of crude DDNP, only 1.8g of recrystallized DDNP was obtained which is typical of my material. BTW, I also started using acetone at or near the boiling point to dissolve the crude DDNP, which cuts the amount of acetone needed in half or less (I haven’t bothered to determine the exact solubility yet).

[Edited on 15-3-2014 by Hennig Brand]

Hennig Brand - 15-3-2014 at 07:02

Wanted to clarify something just to keep the reporting as honest as possible. Once all the burrs and paint have been removed from the witness plate it is now measuring about 2.6mm in thickness not 3mm. I should have been a little more careful measuring it earlier. As far as I am concerned this doesn't change the results much if at all, since the tests were more about comparisons and not how much thickness of steel was perforated. The composition and strength of steel can also vary greatly and I have no information regarding the composition of the steel in the witness plate.

roXefeller - 17-3-2014 at 08:51

Have you given any thought to compressing basic lead picrate into the confinement cap and then using a smaller amount of DDNP to follow it (within the confinement cap still)? As my mind thinks about this, I'm curious if it the BLP could wake up over-pressed DDNP.

Hennig Brand - 17-3-2014 at 13:17

Basic lead picrate is a much weaker primary than DDNP. It has a long run up distance to high order detonation and using practical quantities tends to detonate low order. It might be interesting to see what half a gram, or a gram, could do if confined well with a reinforcing cap. I haven't tried it so I can't say for sure, but DDNP is definitely a much more powerful primary.

Some of my earlier tests, in this thread, involved using BLP as a flash igniter to initiate the DDNP. I didn’t test it thoroughly, but it didn’t seem to make much difference whether I used the BLP or not. DDNP accelerates to high order faster than BLP, from reading and my own observation, and it is so easy to light on its own that it doesn’t need a flash igniter. The picrates really aren't very effective initiators in general, but the lead salts (especially BLP) make very good flash igniters.

Regarding DDNP purity, I mentioned above that I thought purity was an issue with the DDNP I made. The reason I gave was that there were large losses during recrystallization. At this point I wonder how much of that loss was because of sloppy recrystallization technique. Next time I will be a lot more careful with the amount of acetone used to dissolve the crude DDNP. After all, the crystals formed from evaporative recrystallization earlier in this thread, with no prior purification step, looked fairly clean and well formed under the microscope.

I am out of reinforcing caps and aluminum detonator casing material right at the moment or I would be trying to initiate picric acid, in the above configuration, using only 0.30g of DDNP. It will likely be a month or so until I will have the time and be close enough to a lathe to do more testing. The reinforcing caps can be made with only a hand drill with a little more difficulty, but I am still out of range of more aluminum tubing at the moment. I made an aluminum reinforcing cap, from aluminum round stock, with just a hand drill and a hack saw a couple of days ago and it wasn't that difficult. It isn't as convenient, or as easy to produce consistent results, as when using a lathe however.

[Edited on 18-3-2014 by Hennig Brand]

Free Flowing DDNP from Sodium Picramate

Hennig Brand - 23-3-2014 at 04:19

The first time I tried making DDNP directly from sodium picramate I used basically the same method as the one in COPAE, which was for picramic acid to DDNP. The only difference was that a small excess of HCl was added, since it was felt that a stoichiometric amount should be added to convert the sodium salt. The result was a much reduced yield than when picramic acid was used. At the time, it was very obvious that the reaction proceeded much more slowly than when picramic acid was used. When picramic acid was used, the color change from a reddish brown color to DDNP brown was almost immediate once the sodium nitrite solution was added. However, when sodium picramate was used it took several minutes and then the brown color slowly developed.

Using the attached paper titled, "DDNP, A Detonating Explosive" as a guide I increased the reaction time a lot, as well as a couple of other small changes.

Experimental

5g Sodium Picramate
72 mL 5.5% HCl
1.9g NaNO₂ in 30 mL H₂O

The 5g of sodium picramate was suspended in the 72 mL of 5.5% HCl and stirred vigorously with magnetic stirring for 10-15 minutes in an ice bath (long enough to lower the temperature of the mixture to about 10-15⁰C. Stirring and cooling was maintained and the 1.9g of NaNO₂ in 30 mL of water was added all at once. The temperature rose slightly, when the sodium nitrite was added, but never went above 20⁰C and dropped to about 5⁰C by the end of the reaction. The stirring was continued and the reaction allowed to proceed for 1 hour at which point stirring was stopped and the DDNP was filtered out using gravity filtration. Filtering was easier, compared to the method starting with picramic acid, since the particles were larger and didn't plug the filter as badly or hold liquid as much. The DDNP was washed, in the filter, with small quantities of ice cold water. Yield was quantitative.

The material obtained by this method is much more dense and free flowing than the material made more directly from picramic acid using the COPAE method. The picture shows the material as being in small clumps, however, very light pressure from the back of a spoon or even folding the filter paper causes it to break up into dense free flowing powder.

Although this method leaves out what could be a valuable purification step, going from sodium picramate to picramic acid, it results in a much more dense free flowing material and is much less labour intensive as well (less steps). The much slower reaction rate greatly improves the density and handling properties of the produced material.

Attachment: DDNP a Detonating Explosive.pdf (997kB)
This file has been downloaded 800 times

[Edited on 23-3-2014 by Hennig Brand]

2g of Picric Acid Initiated in 7.6mm id Al Tubing by 0.30g of Hand Pressed DDNP in Steel Reinforcing Cap

Hennig Brand - 22-4-2014 at 14:29

The test was performed with the same materials and in the same way as the last test. The picric acid was not driven hard enough by the 0.30g of DDNP even with very strong confinement. Picric acid needs to be given a really hard kick to produce full output power. There was every indication of a complete detonation, complete with cloud of black smoke, but the damage to the steel plate was much less than when the picric acid was overdriven properly. There was no clean hole blown through the steel witness plate, but there was a big dent on the top side and a scab blown off the bottom side as well as cracks which went all the way through the plate. The dent/scab on the right in the witness plate photos is from this test.

The next test will probably involve a little lead azide or silver azide to get the DDNP off to a good start.

[Edited on 22-4-2014 by Hennig Brand]

Jimbo Jones - 23-4-2014 at 00:26

Fascinating stuff Brand. Thanks for the hard work and the effort to put all this data and tests in the forum.

Have you ever test or planning to test the friction and impact sensitivity between DDNP and lead azide?

Hennig Brand - 23-4-2014 at 06:38

Thank you. So far I haven't done much for friction and impact testing, but I can tell you it takes a harder blow to set off DDNP than the other primaries I have tested such as lead azide, silver azide, lead styphnate, mercury fulminate, TATP, HMTD, etc. I haven't used a proper testing apparatus to accurately quantify the difference, but I can say that even with a crude hammer test it is obvious that DDNP is significantly less sensitive to impact than most other primaries commonly used. Crude tests with hammer on concrete indicate that it is relatively insensitive to friction as well.

Bert - 23-4-2014 at 06:54

Related to the shock/friction question testing question above-

Have any members gone so far as to MAKE either a drop hammer or friction shoe apparatus? On a quick search, I find only 1 EM thread regarding this?

http://www.sciencemadness.org/talk/viewthread.php?tid=26165#...

Likely several professional members have equipment at work, but do any "advanced amateurs" bother to?

Jimbo Jones - 23-4-2014 at 07:15

Quote: Originally posted by Hennig Brand

Thank you. So far I haven't done much for friction and impact testing, but I can tell you it takes a harder blow to set off DDNP than the other primaries I have tested such as lead azide, silver azide, lead styphnate, mercury fulminate, TATP, HMTD, etc. I haven't used a proper testing apparatus to accurately quantify the difference, but I can say that even with a crude hammer test it is obvious that DDNP is significantly less sensitive to impact than most other primaries commonly used. Crude tests with hammer on concrete indicate that it is relatively insensitive to friction as well.

Thanks. Its interesting information, even the primitive tests conditions. Maybe I’ll give a try to DDNP someday. I think a mixture of DDNP and around 20 – 30 % SADS will be something worth to try.

Anyway. Very good job and thanks again for the nice reading from you and Rosco.

Jimbo Jones - 23-4-2014 at 07:27

Quote: Originally posted by Bert

Related to the shock/friction question testing question above-

Have any members gone so far as to MAKE either a drop hammer or friction shoe apparatus? On a quick search, I find only 1 EM thread regarding this?

http://www.sciencemadness.org/talk/viewthread.php?tid=26165#...

Likely several professional members have equipment at work, but do any "advanced amateurs" bother to?

Yes. AXT have done it.

http://www.youtube.com/watch?v=_Xx-zhALHjM

http://www.youtube.com/watch?v=PAuzMOd9L48

I also made similar, but more simple rig years ago. It’s easy to assemble even with almost now tools.

2g of Picric Acid Initiated in 7.6mm id Al Tubing by 0.25g DDNP & 0.05g of Lead Azide Hand Pressed in Steel Reinforcing Cap

Hennig Brand - 23-4-2014 at 13:26

This test was performed with the same materials and in the same way as the last test except that 0.05g of the 0.30g of DDNP was replaced with lead azide. The 0.05g of lead azide was hand pressed into the reinforcing cap first followed by the 0.25g of DDNP. Lead azide, being a more instantaneously detonating or unequivocal primary explosive, made the transition from deflagration to detonation very quickly thereby eliminating the longer run up distance that is needed when DDNP is used alone. It is obvious from looking at the witness plate shots that the picric acid was driven much harder in this test than in the last. The hole produced in this test was not quite as large as in some of the tests where more DDNP was used, but it looks as though very little more picric acid output would be needed to produce similar results as was seen in those previous higher output tests.

The next experiment will be to form a small amount of silver azide on the surface of a stirred suspension of DDNP crystals. Apparently very small amounts of silver azide formed on the surface of sluggish primaries can help them make DDT much more quickly.

Yes, as long as SADS is compatible with DDNP it would probably be a good paring too.

The holes on the right, in the witness plate shots, are from this test.

[Edited on 24-4-2014 by Hennig Brand]

historical variations as alternative methods

Rosco Bodine - 7-5-2014 at 01:21

There is a patent US1460708 which describes a variation of a much older method of producing DDNP reported by Stenhouse in 1868, both references attached.

Attachment: US1460708 process for DDNP.pdf (319kB)
This file has been downloaded 672 times

Attachment: Pages 150-151 re DDNP Vol 21 (1868) Journal_of_the_Chemical_Society.pdf (144kB)
This file has been downloaded 854 times

PHILOU Zrealone - 7-5-2014 at 07:04

Does someone know if the following do exist?
-Diazo-dinitroaniline DDNA (or DNBTA dinitrobenzotriazole)
-Di-diazodinitrohydroquinone (DDDNHQ)
-Di-diazodinitroresorcinol (DDDNR)
-Dinitrobenzobistriazole (DNBBTA)
-Dinitrodiazoxybenzotriazole (DNDBTA)

Hereunder molecular structures vs related DDNP.

All those should display good densities and detonic properties although the di-diazoxy compounds might be very sensitive probably more than the DDNP.
The tricyclic compounds will be denser than the initial DDNP (d=1,63 (max density of bulk), d=1,71 (cristal)).

Note that the molecules containing a triazo ring hold also an acidic H that would allow to make energetic amine salts (NH4, N2H5 or NH3OH) or energetic metalic salts.
The anionionic result of those are fully aromaticized what is good at increasing the density.

Those triazo ring are maybe in equilibrium with azido benzene structure what are known to be relatively stable if an ortho nitro group is present (under heating those are oxydo-reduced to di-nitroso (furoxan) compounds.
-C(-NH-N=N-)C- <==> -CH=C(-N3)-
-C(-NO2)=C(-N3)- <==> -C(-N=O)=C(-N=O)- + N2
-C(-N=O)=C(-N=O)- <==> -C(=N(O)-O--N=)C-
This is good for thermal stability.

The acidic hydrogen atom can switch to the opposite nitrogen of the same triazole ring directly in contact with the aromatic carbon.
-C(-NH-N=N-)C- <==> -C(-N=N-NH-)C-
So two apparent different molecules are in fact identical (this effect is not observable with the diaza-oxy heterocycles.

[Edited on 8-5-2014 by PHILOU Zrealone]

Also what about detonic properties of Iso-diazodinitrophenol (IDDNP) (see picture hereunder vs usual DDNP)?

[Edited on 8-5-2014 by PHILOU Zrealone]

Rosco Bodine - 8-5-2014 at 09:29

This is not exactly what you are asking about but seems somewhat related and interesting

Attachment: Diazidodinitrohydroquinone H-228 from Vol. 7 H-L.pdf (88kB)
This file has been downloaded 770 times

Attachment: GB207563 Diazidodinitrohydroquinone.pdf (371kB)
This file has been downloaded 601 times

[Edited on 8-5-2014 by Rosco Bodine]

2g of Picric Acid Initiated with 0.4g of DDNP & 0.1g of Lead Azide (Unreinforced Configuration)

Hennig Brand - 11-5-2014 at 06:04

This test involved the initiation of 2g of picric acid without a reinforcing cap. Two grams of picric acid was incrementally lever pressed into a 7.6mm aluminum casing followed by 0.4g of DDNP (hand pressed) followed by 0.1g of lead azide (hand pressed). Visco fuse was used as a delay element and the end was sealed with hot melt glue.

There was a complete detonation but a clean hole was not blown through. I now believe that this is because of not pressing the picric acid base charge to as high a density as in some of the early tests. I had to change the loading dowel that I was using a while back and in doing so created a situation where there is less mechanical advantage obtained from the lever press. Another test will need to be performed with the picric acid base charge at a loading density similar to the early tests.

The holes on the right, in the witness plate shots, are from this test.

BTW, I tried coating 4g of DDNP with silver azide so as to make a primary explosive composed of 5% silver azide and 95% DDNP. Previously prepared DDNP was put into a well stirred suspension in water with the correct quantity of dissolved silver nitrate. On adding the sodium azide solution, slowly with a pipette, effervescence was seen. I guess the solution was acidic; there could very well have been significant amounts of picramic acid contamination with the DDNP especially since the sample of DDNP used was not recrystallized.

[Edited on 11-5-2014 by Hennig Brand]

2g of Picric Acid Initiated with 0.4g of DDNP & 0.1g of Lead Azide (Dry Mixed Primary & Unreinforced Configuration)

Hennig Brand - 11-5-2014 at 06:22

This test involved the initiation of 2g of picric acid without a reinforcing cap. Two grams of picric acid was incrementally lever pressed into a 7.6mm aluminum casing followed by 0.4g of DDNP & 0.1g of lead azide which were dry mixed before being hand pressed into the detonator casing. Visco fuse was used as a delay element and the end was sealed with hot melt glue.

As in the last test, there was a complete detonation but a clean hole was not blown through. I now believe that this is because of not pressing the picric acid base charge to as high a density as in some of the early tests. I had to change the loading dowel that I was using a while back and in doing so created a situation where there is less mechanical advantage obtained from the lever press. Another test will need to be performed with the picric acid base charge at a loading density similar to the early tests.

The holes on the right, in the witness plate shots, are from this test.

[Edited on 11-5-2014 by Hennig Brand]

Bert - 11-5-2014 at 06:24

A safety related point: Hot melt glue is... Hot.

There have been deaths associated with use of hot melt adhesives on commercial assembly lines for consumer pyrotechnics in USA manufacturing plants.

While there ARE low temperature adhesives and thermostatically controlled glue systems available, I'd still be reaching for the 5 minute epoxy if sealing a metal device with live material installed. Just not worth adding another potential ignition source for a bit of speed/convenience!

And if it's a cheap consumer grade tool from the hardware or craft store- Well, read this:

http://www.amateurpyro.com/forums/topic/3530-hot-glue-guns/

http://www.lawyersandsettlements.com/news/02336/Glue-Gun-Fir...

[Edited on 11-5-2014 by Bert]

Hennig Brand - 11-5-2014 at 07:32

I use the low temperature variety and push in a little wad of tissue in the casing over the primary and beside the fuse before applying the glue. I also clean the inner and outer surfaces of the cap casing end as much as possible before gluing as well. I have always suspected that it was a bit of a risk though. For instance if a glue gun malfunctioned and was hotter than normal it could have dire consequences.

Thanks for the concern and the links. Unplugging the glue gun before use is a good idea, and is one which I have used in the past.

[Edited on 11-5-2014 by Hennig Brand]

Rosco Bodine - 11-5-2014 at 07:33

For the integration of silver azide and DDNP a different scheme may be better.
What I think could work is form the silver azide separately as a colloidal or somewhat larger form and substantially dry it and then suspend it stirred rapidly in warm toluene. Dissolve the DDNP in warm acetone and add that gradually to the stirred suspension. A small and very gradual addition of water should complete the precipitation of the DDNP. Any trace acidity in the DDNP could be neutralized with ammonia or ammonium acetate or carbonate.

It would probably serve even better to divide out a portion, maybe a third of the silver azide and add it last to the stirred suspension, to accomplish external as well as included particles of the silver azide with the DDNP. Some of the graining additives like PVA and a surfactant could be helpful also in the agglomeration of the particles as a density improver.

[Edited on 11-5-2014 by Rosco Bodine]

Bert - 11-5-2014 at 08:15

How about dissolving some Viton in that acetone? Poly vinyl alcohol is water soluble, as I recall it resists organic solvents very well?

Rosco Bodine - 11-5-2014 at 09:20

Stearic acid, ester gum, microcrystalline wax, shellac, red gum, rosin, even latex or acrylic aqueous colloidal suspension paint component, and some urethanes soluble in acetone like aluminum marine grade "trailer kote" polymerize anerobically on exposure to moisture ...there are many possible candidates for trace adhesive tackiness as a graining additive and density improver even in very small amount ranges like a few hundreths of a per cent impurity. Red goo is always good, works for everything

Edit: linseed oil is another possible tackifier

Another potentially better scheme for coating the DDNP with silver azide could make use of the stability of DDNP to acetic acid. Acetone and acetic acid could be used to dissolve DDNP and then an aqueous ammonia solution of Silver Azide
sould be added. The neutralization of the ammonia by the acetic acid would cause the dissolved silver azide to preciptate, and likewise the moisture from the aqueous solution of silver azide would cause precipitation of the DDNP. Either order of addition should work but one or the other may produce a better result. I tend to favor the order of addition that would be adding the ammoniacal aqueous solution of silver azide to the warm acetone and acetic acid solution of DDNP. A milder less pH extreme variation technique would be concurrently adding the acetic acid and the ammoniacal solution of silver azide as parallel additions to the warm acetone solution of DDNP.

[Edited on 11-5-2014 by Rosco Bodine]

2g of Picric Acid Initiated with 0.4g of DDNP & 0.1g of Lead Azide (Dry Mixed Primary & Unreinforced Configuration)

Hennig Brand - 11-5-2014 at 10:43

I got the density of the picric acid base charge back up to more or less what it was in earlier tests, other than that this test was the same as the last test. As expected the higher density picric acid detonated with higher velocity and caused more damage to the steel witness plate on detonation. A hole was blown through, but was not really a clean hole. The reinforcing cap from earlier tests may have not only had a lot to do with the higher efficiency of the DDNP primary but also the picric acid base charge.

What I need is a gauge of some sort so that loading pressure can be easily monitored during cap loading. I guess a set of bathroom scales can be made to work in a sort of improvised arrangement.

The holes on the right, in the witness plate shots, are from this test.

Regarding silver azide and DDNP mixtures, I am not all that familiar with some of the things you are proposing, but it sounds interesting. How is ASA made? I always assumed that the lead azide, lead styphnate and aluminum powder were dry mixed or damp mixed, but I never really knew for sure what was actually done.

[Edited on 12-5-2014 by Hennig Brand]

Rosco Bodine - 11-5-2014 at 11:07

What exactly is the mil spec standard ASA mix I am not certain. I think the ASA is a solvent damp mix using a bit of gum or wax or other material as a binder and pressure flowable sealer. Even a small percentage of TNT can be used as an additive there and to help seal the pressed composition. The fine flake aluminum also serves as a physical barrier like shingles on a roof so the mixture is pretty well sealed as a compressed pellet and is storage stable.

Bert - 11-5-2014 at 11:23

Quote:

What I need is a gauge of some sort so that loading pressure can be easily monitored during cap loading. I guess a set of bathroom scales can be made to work in a sort of improvised arrangement.

A cheap 1 ton arbor press from Harbor Freight or similar (Canadian Tire?):

http://m.harborfreight.com/1-ton-arbor-press-3552.html?utm_r...

A torque wrench in place of the supplied handle:

http://www.amateurpyro.com/forums/topic/8695-arbor-press-tor...

A load cell/pressure gauge to calibrate if needed:

AND!!!

A blast shield between you and the pressing operation- You can only stay lucky so long...

https://www.sciencemadness.org/whisper/viewthread.php?tid=30...

[Edited on 11-5-2014 by Bert]

Hennig Brand - 11-5-2014 at 11:55

Thanks for the good suggestions. Yes, it is true, you can only stay lucky so long. There will always be risk, but the idea should be to try and keep it to a minimum, while at the same time not being paralysed by fear to the point of not being able to try new things.

I like the arbor press idea. I almost got a good second hand one a while back, but as you pointed out they are not necessarily that expensive new anyway. I took a picture of the pellet press we were using to prepare fuel samples for a bomb calorimetry lab. I think one of these would be fairly easy to build from junk yard steel and would work quite well. A larger one than is shown in the picture might be more desirable for our purposes. The pressing surface, where the die sits, is threaded and can be adjusted for height by turning it. There is a spring in the body of the press that places enough upward pressure on the press plunger to keep it in the upward position until the lever is pushed down.

Found this patent which gives a little background information regarding the lead azide, lead styphnate & aluminum powder primary explosive mixture ASA.

Attachment: Patent Regarding ASA.pdf (401kB)
This file has been downloaded 862 times

[Edited on 11-5-2014 by Hennig Brand]

PHILOU Zrealone - 12-5-2014 at 13:16

Just want to point out that silver nitrate or other salts are usually uncompatible with ammonia... so Rosco's idea is rather dangerous!

silver nitride/amide

Rosco Bodine - 12-5-2014 at 15:20

Have you read the literature regarding silver azide manufacture? I should post a few references about silver azide manufacture processes in the azides thread. The use of ammonia has been common for more than 50 years.

I'll just post the references here, maybe link em later there.
This thread and the associated picramic acid thread are likely headed for being stickied and combined somehow since the topic has become authoritative as a reference.

Attachment: Silver Azide Pages from Technology of the Inorganic Azides, Vol. 2 (1977).pdf (1.1MB)
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Attachment: US3943235 Process for Silver Azide Costain.pdf (449kB)
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Attachment: Silver Azide preparation a132994.pdf (1MB)
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Attachment: GB887141 Imrovement in silver Azide.pdf (188kB)
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Attachment: GB781440 Improvements in Silver Azide manufacture.pdf (378kB)
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[Edited on 13-5-2014 by Rosco Bodine]

Rosco Bodine - 12-5-2014 at 16:24

British Mil Spec Silver Azide RD1336

Attachment: Silver Azide RD-1336.pdf (1.9MB)
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http://translate.google.com/translate?depth=1&hl=en&...

Attachment: Exploders Google Translate AgN3.pdf (8kB)
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[Edited on 13-5-2014 by Rosco Bodine]

PHILOU Zrealone - 13-5-2014 at 05:05

Quote: Originally posted by Rosco Bodine

Have you read the literature regarding silver azide manufacture? I should post a few references about silver azide manufacture processes in the azides thread. The use of ammonia has been common for more than 50 years.

I'll just post the references here, maybe link em later there.
This thread and the associated picramic acid thread are likely headed for being stickied and combined somehow since the topic has become authoritative as a reference.

[Edited on 13-5-2014 by Rosco Bodine]

I stand corrected

.

In one of your reference they mention that there is indeed a risk and a safety concern about Ag nitride/amide; but that the heating/venting (exhaust of all the NH3 from the media) and that the neutralisation by nitric acid (or acetic acid) both allow the nearly complete conversion of the silver into AgN3 and avoid further problems with Ag3N, Ag2NH and Ag-NH2.

On another point ammonia and aceton form a Schiff's base (*) what might (or might not) be a problem; your procedure must be tried in tiny amount first.

(*)
(CH3-)2C=O + NH3 --> (CH3-)2C=N-H + H2O
On standing (for weeks) it turns into dark orange-red-brown polymeric material with a phenolic smell.

Rosco Bodine - 13-5-2014 at 07:12

Yeah ammonia and ammonium acetate increase greatly the solubility of azides including also lead azide and this may be helpful to solubility in the azo-clathrate formation but I haven't tried the technique to confirm. Silver fulminate is also desensitized by ammonia forming a complex which can allow its safe handling as the ammonia complex, from which the ammonia volatilizes and escapes gradually on drying and leaves the uncomplexed silver fulminate as its usual sensitive form. I think IIRC it was Gerald Hurst patented that ammonia complexation process for silver fulminate, so there is a parallel history for use of ammonia even with actual fulminate, under conditions which may still present the goblin possibility of formation of the unwanted "fulminating silver" nitride. Process control is everything there for avoiding unpleasant surprises.

Hennig Brand - 15-5-2014 at 17:36

This file has already been attached in the azides thread, but it seems important enough to put here also. In this report they examined a number of different sensitizers for silver and lead azide. The good news is that DDNP seems to be compatible with both lead and silver azide. The bad news is that DDNP seems to be a very effective sensitizer of both lead and silver azide. I would need to look into it further, but the stab initiation energies table on page eighteen shows extreme sensitivity increase when DDNP is added to either lead or silver azide. In fact, of the handful of sensitizers they tested, DDNP was the second most effective sensitizer in both cases.

Nice to know lead and silver azide are compatible with DDNP, but I think it might be best to just put a little azide on top of a DDNP charge rather than mix the two. I suppose this could be what some of those references meant when they stated that lead azide and DDNP were incompatible; kind of like when safety sheets say ammonium nitrate and fuel oil are incompatible.

File can be viewed here.
http://www.sciencemadness.org/talk/viewthread.php?tid=1987&a...

[Edited on 16-5-2014 by Hennig Brand]

Rosco Bodine - 15-5-2014 at 18:19

I just posted that Australian reference above. I would disagree about the sensitivity because what is being described is specifically a particular type of sensitivity to a compressed pellet being pierced by a sharpened firing pin called a "stabber" or a stab detonator. The compatability of DDNP with lead azide was such that it may adversely affect the storage life of the lead azide, not that it causes any dangerous sensitivity. And the same thing is reported about the ASA mixture being an incompatible mixture of lead styphnate with lead azide because of an increased decomposition rate of a mixture of lead azide with lead styphnate that reduces the storage life. But as a practical matter the advantages of the ASA mixture outweigh the slight reduction of the storage life for pure lead azide so ASA is used anyway. What is the real compromise if the expected storage life for an ordnance is reduced from a predicted 300 years to only 150, as an example only for the sort of difference or storage life penalty which they are describing when they speak of the incompatability which is more likely limited for the mixture by the DDNP storage stability anyway. The more ideal storage life for the single component is better than for the mixture. But the difference is not so great over any practical storage time expected that
it would be a real concern that would rule out the use of such mixtures.

[Edited on 16-5-2014 by Rosco Bodine]

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