Sciencemadness Discussion Board - Quantitative NHN synthesis without Hydrazine hydrate

Quantitative NHN synthesis without Hydrazine hydrate

fredsci93 - 1-12-2021 at 18:08

NHN or Nickel hydrazine nitrate is a very powerful primary with high storage stability and low sensitivity. The traditional synthesis utilises Hydrazine hydrate or hydrazine sulphate, the former being difficult to obtain and the prior producing inconsistent results, with some members reporting good yields via calcium and barium hydroxide and some members having no success at all with hydrazine sulphate.

Last week I decided to attempt the synthesis with hydrazine dihydrochloride and I was amazed by the results, the yield on my first run was 75% due to a poor hydrazine freebasing technique, these results were still promising so I repeated the synthesis using this technique bellow.

To 24.25g hydrazine dihydrochloride in 50ml ethanol a total of 18.5g of sodium hydroxide was added in portions over ice with stirring, the resulting slurry was mixed for 20 minutes and let sit for 10 minutes, the slurry didn’t separate well so I opted to filter, I gravity filtered it and washed the resulting solids with a total of 50ml ethanol over 2 washes.

A solution of nickel nitrate hexahydrate was prepared by dissolving 14g of nickel nitrate hexahydrate in ~100ml water.

The filtrate was stirred and it's temperature was raised to approximately 60-65C, the nickel nitrate hexahydrate solution was added quickly in 10ml portions yielding a thick slurry of purple precipitate which was stirred for a minute at 60-65C before being hot filtered through two coffee filters which gave a colourless solution and a purple filter cake. The filter cake was not washed as I deemed it unnecessary (however I may be wrong and I only didn’t wash it because the filtrate was so clean), The filter cake was dried over paper towels before being totally desiccated over a steam bath for 4h This yielded 12.9g of product (96% yield)

The yield was more or less quantitative with the losses being mostly due to mechanical losses

The product was able to detonate in small quantities when confined and deflagrates when not confined, it has a moderate sensitivity towards impact, somewhere between lead azide and ETN.

Note 1: it is very important to add the nickel to the hydrazine, otherwise a blue compound seems to form in addition to the NHN, the blue compound is totally non-energetic and likely a hydroxide of nickel
Note 2: I did not dextrinate the compound since I don’t have any dextrin, the sensitivity is alright without any dextrin
Note 3: The compound tends to clump when drying, these clumps can be safely broken up in 0.5g portions with light compression

Image 1: Slurry formed by hydrazine free basing
Image 2: Hydrazine solution on hot plate
Image 3: NHN filtrate
Image 4: NHN filter cake
Image 5: Steam bath setup
Image 6: NHN drying
Image 7: NHN directly after formation

[Edited on 2-12-2021 by fredsci93]

Brightthermite - 2-12-2021 at 16:02

Cant wait to give this a shot, what was your source for hydrazine dihydrochloride?

fredsci93 - 4-12-2021 at 15:11

The hydrazine dihydrochloride and nickel nitrate hexahydrate were both from chemcraft (https://chemcraft.su/product/23119) (https://chemcraft.su/product/24044)

ManyInterests - 5-12-2021 at 06:48

I'm going to be making some very soon. I already have hydrazine sulfate, I just need to make a bit more and make nickel nitrate.

I know your method would probably be better, but I really want to make my stuff from scratch.

[Edited on 5-12-2021 by ManyInterests]

fredsci93 - 5-12-2021 at 12:58

You may want to convert your hydrazine sulfate to hydrazine monochloride with calcium chloride (http://www.sciencemadness.org/smwiki/index.php/Hydrazine_hyd...). Hydrazine sulfate on it's own can work for NHN but from what I've seen it's very particular and has a tendency to just form inert nickel hydroxides.

Homemade nickel nitrate and hydrazine sulfate should work just fine, so long as the reagents are pure enough, since sulphate ions in the reaction mixture will destabilise the complex.

Brightthermite - 5-12-2021 at 17:20

Also question regarding safety, other then gloves and good air flow is there any other precautions I should specifically take when handling hydrazine? I hear it is nasty stuff and I have yet to work with it so Id like to be prepared.

ManyInterests - 5-12-2021 at 18:05

I kept a bottle of calcium hypochlorite solution to spray in case of spills and to degassify the air if I feel like any fumes were out.

fredsci93 - 5-12-2021 at 18:26

Keep all hydrazine solutions covered with glad wrap at all times, maintain good air flow, keep hydrazine solutions far from your face and nose, wear eye and hand protection. Also be very careful with the NHN, it's a very powerful explosive and should be handled with care and respect, it's power decreases exponentially as you add water to it it so for long storage you may want to add 5% water to desensitise it.

I second what Manyinterests said, calcium hypochlorite for treating spills is very important, if there were to be a spill my best advice it to spray the affected area with the hypochlorite and leave for a couple hours, lowering the exposure time is key to safely dealing with any spill.

Microtek - 6-12-2021 at 01:36

If you are going to freebase the hydrazine anyway, what's the point of converting it to the chloride first?

fredsci93 - 6-12-2021 at 02:45

Hydrazine produced from hydrazine sulfate + NaOH seems to be much less suitable for NHN synthesis since some sulfate ions will come over and destabilise the complex, converting to the hydrochloride beforehand removes all sulfate ions which would result in a cleaner hydrazine, if you free base with calcium or barium hydroxide that would also remove all sulfate contamination, either method would work well, I am somewhat stipulating on some of the methods as I have not synthesised NHN with hydrazine sulfate and I am going off other reports, it is possible that hydrazine sulfate + NaOH works well and other people who failed the synthesis were doing something wrong with their methodology, so take everything I say regarding using hydrazine sulfate for NHN with a grain of salt.

ManyInterests - 6-12-2021 at 08:45

Quote: Originally posted by fredsci93

Hydrazine produced from hydrazine sulfate + NaOH seems to be much less suitable for NHN synthesis since some sulfate ions will come over and destabilise the complex, converting to the hydrochloride beforehand removes all sulfate ions which would result in a cleaner hydrazine, if you free base with calcium or barium hydroxide that would also remove all sulfate contamination, either method would work well, I am somewhat stipulating on some of the methods as I have not synthesised NHN with hydrazine sulfate and I am going off other reports, it is possible that hydrazine sulfate + NaOH works well and other people who failed the synthesis were doing something wrong with their methodology, so take everything I say regarding using hydrazine sulfate for NHN with a grain of salt.

I've seen people get decent yields with both hydrazine hydrate (hydrazine sulfate + sodium hydroxide) and azeotropic hydrazine (64%). Pyrotechnical Science on youtube got rather small yields from both, while others got a decent yield. I believe in order to get the best, you do need a touch of dextrine (1% volume of the nickle nitrate you are using) and to make sure the entire thing is done at 65C and not above, maybe a little below, but 65C is the accepted temperature the hydrazine solution should be at.

Your mention of calcium hydroxide sounds interesting, but I have no access to it right now, or at least I don't know exactly where to get it. I do have plenty of sodium hydroxide and I will be using it out of convenience at the moment. If I get a yield of 3 grams I would consider that a good yield.

S.C. Wack - 6-12-2021 at 15:35

Quote: Originally posted by Microtek

If you are going to freebase the hydrazine anyway, what's the point of converting it to the chloride first?

This would be problematic in alcohol with cooling and the sulfate.

Shaking with a bunch of small glass beads might help in that case.

ManyInterests - 8-12-2021 at 09:37

Quote:

This would be problematic in alcohol with cooling and the sulfate.

What if we kept the denatured ethanol in the freezer for a while to keep it super cold?

S.C. Wack - 8-12-2021 at 14:51

What I think is, that all the accounts which were created years ago but were dormant for 1.5+ years before suddenly becoming active with many posts for a time, have more than that in common.

It was shocking to see that L. Lerner agrees with me...saying that yield of hydrazine in alcohol with base suffers when the sulfate is used. Inorg Syn gives directions for making the hydrochloride from the sulfate with little loss...via the benzalazine...if one happens to have spare benzaldehyde. (or other similar molecules)

[Edited on 8-12-2021 by S.C. Wack]

Laboratory of Liptakov - 9-12-2021 at 06:50

I find in patents this: Abstract
A process is provided, applicable to the production of hydrazine, which assures a continuous and constant production of azines without the need for detailed control of the working solution. According to the invention, azines are synthesized from oxygenated water, ammonia, and a reactant having a carbonyl group, by the following steps. The reactants are contacted with a working solution in order to obtain azine. The working solution is separated from the azine and possibly from the excess amount of reactant having a carbonyl group. All or part of the working solution is brought to a temperature above 130{degree}C, the water of reaction being eliminated before, after, or simultaneously. The working solution is then recycled to the first step. A product capable of maintaining azine production is introduced into the working solution at some point in the preceding stages. This product is preferably chosen from among acetic acid, ammonium acetate, and acetonitrile. The azines are hydrolyzed in order to obtain hydrazine hydrate. 1 fig.
link: https://www.osti.gov/etdeweb/biblio/6084367

Oxygenated water is what? Introduction ozone gas into water? Thus mixing ammonia water + acetic acid + ozone = hydrazine hydrate production?
Without next catalyseur? So easy? ... :cool:

In this process will sure some problem.

Microtek - 9-12-2021 at 08:35

I think the "oxygenated water" is hydrogen peroxide. I found that US6605265 is very similar to what is described here (and it seems to be the same authors).

Laboratory of Liptakov - 9-12-2021 at 08:57

Not, I finded different between oxygenated water and peroxide. Is it not the same. Oxygenated water is only oxygen dissolved in water.
Thus H2O + O2. Peroxide is H2O2, thus some a like aqueous acid. It are two different solutions. Any way, if works both, is it pretty interesting. Production ozone is (or can be) easily than H2O2. Bigger problem can be mixing next compounds for sucessful result. According patent it seems, that destillation column is necessary.

Maybe try easy attempt, mixing Ammonia water + acetic acid + H2O2 is closure solid container. (ratios unknown yet) And heated it on 100 C. Cooling after 2 hours. And try adding Ni(NO3)2 solution. If arise pink NHN powder, works it.

[Edited on 9-12-2021 by Laboratory of Liptakov]

Microtek - 10-12-2021 at 06:09

I know what hydrogen peroxide is, I just think that the correct term has been lost in translation. If you look closely, you can see that the abstract you referenced is from a patent application in French, specifically Canadian patent number CA 2017358. The original French abstract is:

Quote:

L'invention concerne dans un procédé continu de synthèse d'azines à partir d'eau oxygénée, d'ammoniac et d'un réactif portant un groupe CO...

The term "d'eau oxygénée" might be literally translated as oxygenated water, but a translation such as:

The invention relates to a continuous process for the synthesis of azines from hydrogen peroxide, ammonia and a reagent bearing a CO group.

would be more correct. The patent also exists in english versions, but if you need it, the original can be found at:

https://www.ic.gc.ca/opic-cipo/cpd/eng/patent/2017358/summar...

Laboratory of Liptakov - 10-12-2021 at 08:00

Oh yes, patent use hydrogen peroxide, others is wrong in translation. The point is to try it.

ManyInterests - 10-12-2021 at 14:25

I just want to report what happened in my first attempt at making Nickel Nitrate... it was very much a cartoon event! Thankfully I escaped unharmed and none of the equipment was harmed and I cleaned the spill.

I added 20 grams of nickel metal (cut into chips) and added around 6 ml of 35% hydrogen peroxide... but I didn't realize just what an effect adding the nitric acid to it would have (I used 30ml of 70%)... I had a small fountain of nitric acid fumes and liquid. I quickly put the thing down in my balcony and immediately poured large amounts of bicarbonate water. I had to wipe a lot of the spill by hand after and tried to collect as much of the nickel metal chips as I could. This was quite an event, but my only real loss is that I didn't have much nitric acid left. I had enough for one more synthesis of this kind. I had some more nickel metal chopped up and ready, so I used them. I added the nitric acid first, and I carefully put it below my reflux column first BEFORE (drop wise) adding around 2 or 3 ml of hydrogen peroxide. I nearly had another fountain event, but I quickly put it in the column and no spill occured.

Damn that was something! I put the small (100ml) boiling flask that I am using for this and putting that in a 1000ml beaker full of boiling water at 100C. It's not refluxing yet, but I hope it will. making nickel nitrate is an adventure!

I don't know how long it needs to be doing that in the hot water, but I hope I will be good in four hours or so.

S.C. Wack - 11-12-2021 at 21:20

Quote: Originally posted by fredsci93

The product was able to detonate in small quantities when confined and deflagrates when not confined

FWIW the original lit says "Im Porzellantiegel erhitzt, explodiert die Substanz aufserordentlich heftig unter heller Lichterscheinung."

(goes boom when heated)

It was made in a different way of course...the total amount of water present gave a 10% concentration of nitrate (w/v) and hydrazine hydrate (v/v) at mixing. The product was digested hot for a time, washed, and dried...just one of many nickel and other metal salts with hydrazine that they made.

fredsci93 - 12-12-2021 at 01:36

Quote: Originally posted by S.C. Wack

FWIW the original lit says "Im Porzellantiegel erhitzt, explodiert die Substanz aufserordentlich heftig unter heller Lichterscheinung."

(goes boom when heated)

I haven’t tested it as well as I assume they have, however I know that in DIRECT flame it simply deflagrates even in >200mg amounts, however possibly in indirect heat it's more likely to detonate, I can’t remember well, if I get around to testing it later, I'll inform you

I have tested it in confinement though and it's incredibly powerful and impressive, it's nearly as powerful as a secondary with the DDT of a primary (by which I mean the ability to explode in high yields even in small amounts)

One thing I should note as an unrelated point of information is that NHN has an excellent heat sensitivity and can be brought to very high temperatures without any decomposition >100C

S.C. Wack - 12-12-2021 at 15:45

219C is a temperature which has been given for it to explode. It's also supposed to be not insensitive to electricity; good news I guess for certain detonators, bad news for winter static.

[Edited on 12-12-2021 by S.C. Wack]

ManyInterests - 12-12-2021 at 19:19

Out of curosity. I've seen videos were NHN was synthesized when putting in the nickel nitrate into the hydrazine hydrate, but also the other way around. Is it safe to heat up hydrazine hydrate in an erlenmeyer flask to 65C and not risk the fumes? I could of course cover it. But I need to put the thermometer through in order to accurately measure the temperature.

fredsci93 - 12-12-2021 at 19:42

Yea, it’s fine so long as the beaker is mostly covered (as shown in the photos)

ManyInterests - 14-12-2021 at 20:22

so... hurray! I appear to have succeeded.

Bad news? I seem to have a problem cleaning my buchner funnel. The frit is contaminated with minute amounts of NHN and since I am putting sodium hydroxide through it to neutralize it, it is turning green from nickel oxide... Is my buchner funnel done for? I planned on giving it away for someone to use to make food grade stuff. I figure it is kinda useless now for that purpose?

fredsci93 - 14-12-2021 at 20:33

nah, it's fine just wash it with sodium hydroxide then hydrochloric acid, the hydrochloric acid cleans off any nickel oxide

ManyInterests - 14-12-2021 at 20:54

That's good to know. How dilute does the HCl need to be?

fredsci93 - 14-12-2021 at 21:44

maybe 10-5% it doesn’t matter much, just enough to dissolve the small amount of nickel oxide

ManyInterests - 14-12-2021 at 22:07

OK, so my HCl is around 31.5%, so to 1 part of that, add 2.5 parts of water. simple enough.

[Edited on 15-12-2021 by ManyInterests]

fredsci93 - 15-12-2021 at 00:58

yea, it's not an exact science, anywhere between 15% and 5% would probably work

ManyInterests - 17-12-2021 at 15:23

Here is my end result! 8 grams (wow! I wasn't expecting that much!) of clay like NHN. I did burn the filter paper and I did hear the snap and crackle that is characteristic of small NHN deflageration.

That being said. It seems like I added too little dextrin to the nickel nitrate, or the dextrin should have been added to the hydrazine. At any rate. I will need to very carefully grind them up with a rubber spatula, just like the documentation said.

Edit: After grinding I had apparently lost 0.2 grams (enough for a cap!) that got stuck to the containers.

I hate to throw them away. But after this... well, I'm soaking them in sodium hydroxide solution to neutralize the NHN. I will throw the water after and throw them in the trash. I can always get more glass baking pans.

[Edited on 17-12-2021 by ManyInterests]

fredsci93 - 17-12-2021 at 15:56

Yea, you’ll always lose a bit to mechanical loses, but 8g is a very nice amount, enough for 40 detonators which should last a very long time, in confinement does the NHN strongly detonate? (Don’t test to much, I usually use remote detonator for my first test or two, just to get a feel of how much I can test at a time)

ManyInterests - 17-12-2021 at 16:56

40 detonators? That's quite a lot. I was thinking around 16. The reason is I was using the improvised munitions manual as a guide on making improvised detonators.

They recommend 1 gram of a booster (RDX, picric acid, or ETN/PETN) combined with anything from 3 grams of lead picrate to one gram of TACC, 0.5 grams of DDNP, or 0.75 grams of mercury fulminate, HMTD, or double salts.

I mentioned it several times before that I am using a pen body for a detonator casing. How much ETN and NHN should I put in? How much black powder for the ignition mix? ( I will be using an electric match. I will seal the other end with hot glue.

Edit: I was planning on usnig 0.5 grams of NHN, using the same amount as DDNP (albeit NHN has a det velocity of 7000mps, while DDNP is around 5500).

[Edited on 18-12-2021 by ManyInterests]

fredsci93 - 17-12-2021 at 17:17

I use about 200mg NHN to set off ETN, so long as the ETN is dry and medium/low density 200mg is fine and ~>90 explosive yield compared to using 500mg NHN, since ETN is quite easy to set off, how much explosive you want to use depends on what you want to set off, you won’t need any more than a gram for nearly all secondarys, between 1g and 10g is needed for tertiarys, although all this depends on what explosive you use, DDNP would be fine for a detonator, not sure how much NHN you would need though, maybe 500mg would be required for it, although 0.5g of DDNP might not be sufficient for all secondarys (something like nitrourea which is arguably a tertiary explosive might not be set off)

3g lead picrate is not ideal and you only need that much since lead picrate sucks, if you use a stronger primary like NHN, CHP, AgNTZ, CuNTZ, Ni(NTZ)NO3 etc then you will only need max 500mg (depending on the booster you chose) , but all that depends on what you want to set off, but I would recommend increasing the amount of booster rather than the amount of primary if you want to set off more insensitive explosives since you can separate the primary and the secondary prior to detonations so as to reduce the danger (dealing with 1g primary + 10g secondary separated is much safer than 10g primary + 1g secondary separated or either mix on their own)

For a NHN/ETN pen detonator the amount of black powder is not super crucial, maybe ~1cm worth, just enough to get it all to burn at the same time, for initiating ETN you only need 200mg NHN lightly compressed (LIGHTLY being an important stipulation) ontop of 200mg powdered ETN and however much cast ETN you want depending on what you need the detonator for (minimum 500mg for secondary up to maybe 5g maximum for setting off tertarys, but take that with a grain of salt as I don’t work with tertiarys)

[Edited on 18-12-2021 by fredsci93]

ManyInterests - 17-12-2021 at 18:31

That sounds good. Detonators are an interesting thing. The reason why lead picrate and the other stuff is use is because the improvised munitions manual was written in 1969 and back then things were a little different... on top of that, the laws regarding obtaining reagents was very different back then, and the manual assumes the munitions maker has no chemistry equipment.

The reason why they made the detonator so strong (I believe) is that they wanted to make a detonator that could set off almost all explosives, like dunnite (ammonium picrate, a very stable explosive) or composition B or TNT, which require a booster like tetryl, RDX, or picric acid in order to detonate in addition to the primary.

But right now I'm not really looking to set anything off other than the detonator. So I guess I'll make a few with various compositions... or maybe make them just before I know I will get an opportunity to set them off. I don't think it's a good idea to have blasting caps lying around, especially with the electric match inserted.

When I do get around to setting stuff off I will be making a plasticized ETN/RDX mix (I would have that now, but as you know, my K6/RDX synth went awry) as well as a cheddite explosive (potassium chlorate mixed with petroleum jelly in a 9:1 mixture).

I also made a system of getting the energetic powder into my pen body before pressing.

https://www.youtube.com/watch?v=62kPi5kpbcg&list=WL&...

This video makes a very nice cone that fits well into the inner diameter of my pen but also flares up that it makes loading quite easy. I will be hand pressing, but I will put the pen body in my 5 gallon, sawdust filled bucket with a pair of needle-nosed pliers (away from my hand) and press with the wooden dowel that I will also hold with a pair of pliers.

I won't press too hard. I will gently increase pressure but not give it a ram. No tamping either.

My black powder I believe will work. But maybe in the future I might want to attempt to make faster burning black powder. I tried the wet method (using alcohol and trying to cake and grate the grains) but it didn't work well. The powder still burns well when I put an electric match in it, but it doesn't react when I use a barbique lighter. It's weird that way. So I need to make sure that when I insert the electric match, the match must be enveloped in the black powder to insure ignition.

Gargamel - 19-12-2021 at 11:27

@fredsci93

Quote:

I use about 200mg NHN to set off ETN, so long as the ETN is dry and medium/low density 200mg is fine

What confinement was used in this case?

fredsci93 - 19-12-2021 at 11:57

The NHN is lightly pressed into a PP tube and takes up ~5mm of the tube, a fuse mix is added above it with a fuse inserted, this assembly is then sealed with hot glue and electrical tape.

So the confinement is a PP tube with a hot glue lid, the NHN sits directly ontop the ETN (except for a thin layer of cling film to stop the ETN mixing with the NHN)

B(a)P - 19-12-2021 at 12:50

Quote: Originally posted by fredsci93

The NHN is lightly pressed into a PP tube and takes up ~5mm of the tube, a fuse mix is added above it with a fuse inserted, this assembly is then sealed with hot glue and electrical tape.

So the confinement is a PP tube with a hot glue lid, the NHN sits directly ontop the ETN (except for a thin layer of cling film to stop the ETN mixing with the NHN)

Have you tested this? I would be surprised if lightly pressed 200 mg of NHN would reliably set of ETN.

Gargamel - 19-12-2021 at 13:40

Now I'm even more suspicious

What does the witnessplate say to this?

Just a bang or at least a dent?

Laboratory of Liptakov - 19-12-2021 at 15:44

For reliable DDT, respectively for DDT segment with low density was necessary do mix ETN /NHN 1:1. A like two dry powders, respectively
grains ETN + fine powder NHN. And it even in solid steel cavity. Thats my experiences. Output segment of course cast ETN or high pressed ETN. This described mix is pressed on 5 Kg in cavity 6 mm. With central bridge wire in mix. As plug can be used warm plastic glue. The assemble cast ETN + slightly pressed NHN only, can be not reliable always. Especially in plast cavity.
300 mg high pressed ETN as output segment must deflorate 2 mm steel plate of diameter minimal 6 mm, usually 7 mm.

fredsci93 - 19-12-2021 at 17:13

I haven’t extensively tested it (I did a couple detonations, 3 with one misfire where the NHN wasn’t defligrated/detonated due to a bad fuse + I detonated some ETN with the cap), it's not the greatest design, I'll look at improving it I've just not had a burning need to have a high yield detonator cap right now so the potentially poor explosive yield and overall power has never phased me enough to look into it, but it sounds like it's sub optimal

below is a diagram (not the greatest quality, but you get the idea)

[Edited on 20-12-2021 by fredsci93]

Gargamel - 20-12-2021 at 00:49

Quote:

I haven’t extensively tested it (I did a couple detonations

Can you explain these "detonations"? Did you set anything of with you cap or was it just the caps itself?
Like Doc Liptakov wrote, can you punch through metal?

If the cast ETN is set of properly, that should be no problem. If it is blasted to pieces the whole assembly can still make a hell of a bang but it will initiate nothing.

But thank you for sharing your synthesis, like others, I got frustrated with the sulfate. But I happen to have some dichloride I got as a gift a long time ago and never bothered since

fredsci93 - 20-12-2021 at 01:15

I didn’t test with any metal plates, I have done 3 detonations with just the cap underground and one with the cap and ETN (10g), all but one showed subjectivity good results based off what I expected from prior detonations, the one bad result being one cap which didn’t get properly initated for some reason, I should have tested it's penetrating power on some aluminium or steel, maybe next time I suppose.

Laboratory of Liptakov - 20-12-2021 at 08:17

Witness plate test is necessary for confirmation. All others are only speculations. CHP works a like primary - secondary energetic material.

[Edited on 20-12-2021 by Laboratory of Liptakov]

Microtek - 21-12-2021 at 04:52

When I test energetics for performance, I use the following setup:

- 1.000 +- 0.002 g of the material is pressed into a brass tube of 8mm OD and 0.5 mm wall thickness. The tube is bottomless to avoid errors from varying material thickness. The pressure used is substantial, but unmeasured - I use a vice or my small hydraulic press, so around 100 kg, or 570 psi.

- 0.300 +- 0.002 g of PETN is pressed directly on top by hand.

- The charge is glued into a 3D-printed flange which is then glued onto a piece of 20 +- 0.005 mm thick aluminum bar taken from the same stock to avoid alloy variations. The point of the 3D-printed piece is to ensure an absolutely flush and square contact between the charge and the witness block.

- It is set off using a small 3D-printed cap that fits inside the tube, and contains a wad of fluffy NC. The cap is then closed at one end with a putty made of aminoguanidine nickel perchlorate and NC dissolved in acetone. The other end is closed by design, except for a hole which fits the wire I use. A 20 cm piece of wire is cut off and inserted into the hole (I've designed it to be an interference fit).

- The assembly is placed in a thermobox (ca. 30 liters) filled with crumb rubber in place of coarse sawdust, and initiated electrically using a cheap (1 dollar) boost converter which produces an arc across the end of the wire inside the cap, igniting the fluffy NC.

The dent that the explosion makes in the aluminum block is then measured using a dial indicator as the difference in height between the flat upper surface and the lowest point of the dent. This is then compared to the values I obtained for picric acid, PETN, RDX and HMX, in the same setup.

Not all energetics perform as well as they might under this protocol. Aminotetrazolium nitrate for instance, places between picric acid and PETN. This might well be caused by under initiating or by too little distance to accelerate but this reflects what I require from energetics, since I usually work at the ~1 g scale.

[Edited on 21-12-2021 by Microtek]

katyushaslab - 21-12-2021 at 11:25

Microtek: that is a *very* interesting setup, I might have to borrow some ideas from it. How well does it do with regards noise reduction? I'd imagine it muffles the sound a fair bit?

Microtek - 21-12-2021 at 14:31

Yes, my family doesn't notice the difference between me hitting something with a hammer in my workshop (located below the main floor) and a detonation in my thermobox. I'm sure that coarse sawdust will muffle the noise just as well as crumb rubber, but the rubber is less flammable.

ManyInterests - 22-12-2021 at 10:06

After doing a touch of work with making black powder filled caps (only black powder) and experimenting slightly with the NHN I made I came to the following.

When pressing the ETN and NHN it must be pressed very gently. Not because of the sensitivity, but one thing I noticed is that if I press something too hard into a cap it won't even burn. I've had black powder fizzle, potassium chlorate/nitrocellulose pop well when not super pressed, but fail to do anything when heavily pressed.

Also I realize that NHN is so flame sensitive that it does not an igniter like black powder. Besides... the match head I used on my electric match will produce all the flame needed to set off NHN. Given how unbelievably flame sensitive this stuff is!

Seriously. I took like a tiny pinch of NHN (My scale couldn't measure how much because of how little I put) and the flash it made after the flame so much as licked it was shocking. I was momentarily stunned by its power! My first successful batch was a fine batch indeed!

One other thing is that I apparently am terrible at making christmas light e-matches. I'd better stick to my own design. They need more power to set off, but a 9V battery made of 6 AA is quite small and I noticed will still ignite my match that is set at the end of 3 meters worth of wire. I will test it with a soldered battery pack made of 6 AAAs. But that is just out of curosity.

Brightthermite - 22-12-2021 at 15:01

@Microtek Id love some photos of the 3D printed caps your using and your box! Can you point me in the direction of some info regarding that primarily putty, it sounds interesting.

@ManyInterests its called dead pressing. Good to know the NHN can be dead pressed though, Im sure that will save someone a headache.

ManyInterests - 22-12-2021 at 17:07

I actually don't know if NHN can be dead pressed (yet) because I have yet to construct my ETN/NHN detonator. But now I know that is a thing. I also realize that making a det cap with ETN/NHN is quite safe because there's no way I am going to press hard enough to trigger an accidental detonation. A simple gentle press to hold everything in place and we're all good.

And the matches I use are similar to the design in this video: https://youtu.be/zjAABCRhm8c

I bought my nichrome wire from Aliexpress. I have a ton of good electrical wire from 22 ga to 28 ga (all work fine). I had to practice to make sure I built e-matches that can be inserted into a tight pen body and still not have any of the electrical or nichrome wire move around. I find that the thicker nichrome (0.25mm) is easier to work with, but the thinner (0.1 and 0.08) also works, but you'll need to use more of because it likes to bounce around a lot, so I cut a longer bit of the nichrome and wrap the match head around a few times to make sure the nichrome doesn't bounce around. When I used short wires even 2 AA batteries light up a match with 0.25mm wire on it.

I don't use any lacquer like in the video or put additional ignition powder on it. The match head alone should be sufficient to set off the NHN, especially if the match head is pressing directly against the NHN. If I do need more flame, I have a cotton ball worth of NC left, so I can use a small bit of that.

[Edited on 23-12-2021 by ManyInterests]

[Edited on 23-12-2021 by ManyInterests]

[Edited on 23-12-2021 by ManyInterests]

Microtek - 23-12-2021 at 01:38

If you make a few adjustments to that, you can make a much more reliable system:

Personally, I have moved on from bridgewire ignition but before I did, I used 0.08 mm bridgewires made of kanthal or nichrome (the material doesn't matter that much - the finished assembly just needs to have a resistance of around 2 ohms). I used multistrand wires, which makes it easier to solder the nichrome and a small piece of heat shrink tubing to keep it tidy. Then I ground some match heads up and mixed the powder into a paste with NC lacquer. Then I dipped the end of the wire assembly into this mix. Then after drying, I dipped it one more time.
These e-matches can be set off with three AA-batteries through at least 50 meters of wire and the bridge wire can't become displaced from the pyrogen which is a known flaw of the system with winding the wire around the match head.

@Brighthermite:
The cap is nothing special, but I've attached an stl so you can see for yourself. The box is just a large lidded box of reinforced polystyrene foam that I had lying around. You could just as well use any other kind of box, but there should be some sort of lid or covering on top; otherwise the explosion will scatter your sound absorbing medium everywhere.

Attachment: ArcInsert7_mk2.stl (137kB)
This file has been downloaded 309 times

The putty for the cap is not a great invention either, just my solution for making a simple and reliable means of separating the primary from the base charge. You just dissolve a little NC in acetone and add your primary of choice. It should be flame sensitive and should have a very short DDT, otherwise you may just get a flash. Over the years I have used many different primaries from HMTD and acetone peroxide over lead azide and Roscos azochlathrates to many nitrotetrazole compounds (and NHN). None of them are as effective, safe and reliable as aminoguanidine nickel perchlorate - an ideal primary in my opinion (some of the others are better in some parameters. AgNT is more effective in truly microscopic devices).

[Edited on 23-12-2021 by Microtek]

[Edited on 23-12-2021 by Microtek]

ManyInterests - 23-12-2021 at 03:01

Yeah it's close to what the person is doing in the video. I had to experiment with finding a way of wrapping the wire around the match head to make sure it doesn't move. Then I inserted it and removed it from a detonator body multiple times before proofing it (I.E. applying some current) to set it off and make sure it still works. A dozen times of doing that successfully and I got a working system on my hands.

The main thing is that I don't have NC lacquer and I don't want to get any. I'd rather work with what I have now instead of buying more stuff.

On a side note. When building another test cap (with black powder) I had an premature pop when when I accidentally inserted one of the wires into the NC terminal of my RF module instead of NO. I did check, but I guess the font was small and I was tired. I decided to apply some electrical tape on the NC to block it off and make sure I only insert it into the NO (normally open) terminal. That way I can safely set it all up and detonate with the button when I am ready.

It didn't cause any damage because the cap was already in the bucket. But I should have put it in deeper since I really heard the pop and it did throw sawdust around. On a plus note. It is my first successful pop with my black powder. The amount of pressing required is non-existent and even loosening it up worked. Also hot glue works well to seal a detonator.

Microtek - 23-12-2021 at 03:08

You are not supposed to buy NC lacquer. Just dissolve a little of your NC in acetone. Even if you want to stick with the match, at least apply a coat to keep the wire in place.

ManyInterests - 23-12-2021 at 03:45

That sounds fine. I can do that for sure.