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Hennig Brand
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@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]
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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Rosco Bodine
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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]
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Hennig Brand
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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]
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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Rosco Bodine
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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.
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Ral123
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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?
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Rosco Bodine
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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.
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Hennig Brand
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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.
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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Rosco Bodine
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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 1174 times
[Edited on 9-2-2014 by Rosco Bodine]
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Hennig Brand
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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 1150 times
[Edited on 9-2-2014 by Hennig Brand]
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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Rosco Bodine
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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]
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roXefeller
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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.
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Hennig Brand
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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.
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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roXefeller
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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.
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Hennig Brand
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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.
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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Dornier 335A
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| Quote: Originally posted by roXefeller |
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.
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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.
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Ral123
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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.
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roXefeller
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"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.
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Rosco Bodine
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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.
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Hennig Brand
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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.
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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Rosco Bodine
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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]
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roXefeller
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Amen, Reverend Bodine. If only I could get my colleagues to be skeptics in search of the truth of matters.
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Rosco Bodine
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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]
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Ral123
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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.
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Rosco Bodine
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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.
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Hennig Brand
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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]
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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