Sciencemadness Discussion Board - Storage of lead azide

Storage of lead azide

Katie - 22-4-2020 at 16:29

I’ve been wondering about safe ways to store dextrinated lead azide (DLA). Right now I’ve simply separated what I have into small piles away from any shrapnel producing objects but I’d like to store a supply of both raw DLA and DLA blasting caps.

From what I have read in patents and deduced from chemical suppliers of lead azide is that this chemical is stored and shipped “wet” but I’ve found conflicting and confusing information as to what to wet it with. Some sources say at least 20% of water or a water-alcohol mix, but don’t mention what kind of alcohol. I’ve also read that moisture degrades DLA.

I have available 95% ethanol, 95% methanol-denatured ethanol, 99.98% methanol, 99.8% isopropyl, distilled deionized water, and argon gas. My plan is to saturate the DLA in a 50/50 methanol-water mix and keep in a 100ml Pyrex reagent bottle (GL45 cap) under argon, and store that in a heavy wood box sprayed with anti-static spray, grounded, and kept in place with crumpled paper.

What I’m unsure about is what the best liquid to wet it with is, if they are any dry chemicals that can stabilize it without ruining its performance, or simpler/better ways to store it in general.

As for the blasting caps I plan to fill ¼ inch aluminum tubes with 1-2 grams DLA wetted with methanol, let that dry, and top with FFFFg black powder with 6” 40s/foot waterproof cannon fuse or a model rocket igniter. Unless of course any of that is unacceptably unsafe.

FranzAnton - 23-4-2020 at 08:08

Hi, it depends also of the amount you have, but I would not store it wet if you have less or equal 30g. I would
try to get empty medicine gelatine caps (see picture) or empty some old cheap medicine caps, and fill it in there so you also get fine portions and have a good CO2 shield, because it's sensitive in long therm storage against it. You can store those caps in some sealed plastic container having some silicagel between the caps to keep the gelatine dry. It's some work, but the gelatine caps prevent also from electrostatic discharge. To keep it wet reduces the long time shelf stability imho.

[Edited on 23-4-2020 by FranzAnton]

unionised - 23-4-2020 at 09:21

Quote: Originally posted by Katie

keep in a 100ml Pyrex reagent bottle

Not my field, but I'd go for plastic.
There is an argument in favour of brown glass.- it's easier for the surgeon to see when trying to pick it out of the wound.

ShotBored - 23-4-2020 at 11:47

I haven't worked with it, but I have a peer who worked with it for years in the military explosives sector. Apparently it will detonate under its own weight if stacked too high. LA is terrifying stuff.

FranzAnton - 23-4-2020 at 23:49

if it's dextrinated you have to have a big amount for self ignition under it's own weight.
But I can imagine that we are talking about max. 30g

Herr Haber - 24-4-2020 at 00:17

Quote: Originally posted by Katie

I’ve been wondering about safe ways to store dextrinated lead azide (DLA).

Certainly not safely in a pyrex bottle.
There is no such thing as a safe detonator with 1-2 grams of lead azide. That is the amount you need for 10 or 20 !

Quote: Originally posted by Katie

I have a virtually unlimited supply of PLX, lead azide, ANFO, ANNM, and Ammonal so next time I’m testing things out I’ll pay more attention to the sound and try some different conditions.

Such a shame you dont have a virtually unlimited amount of commercial detonators.
Or finger. Or lives.

[Edited on 24-4-2020 by Herr Haber]

FranzAnton - 24-4-2020 at 05:06

If there exists a "virtually unlimited supply" ---> why storage
better get things when needed

Metacelsus - 24-4-2020 at 05:34

The main benefit of storing under water is avoiding static electricity. That being said, I have stored it dry in the past (in a glass vial in a cool dark place) and it did not explode.

Also note that dextrin will dissolve in water.

[Edited on 2020-4-24 by Metacelsus]

SWIM - 24-4-2020 at 11:58

I don't know a damned thing about storing that stuff, but I wonder if the solubility in water, low though it is, is high enough that long-term wet storage could lead to the formation of larger crystals.

Seems to me I once heard: Large Crystals= Very, Very Bad.

dave321 - 26-4-2020 at 10:46

why cant it be stored under absolute ethanol or ipa (isopropyl alcohol)?

Katie - 26-4-2020 at 18:58

Quote: Originally posted by FranzAnton

If there exists a "virtually unlimited supply" ---> why storage
better get things when needed

By unlimited supply I mean I have easy and reliable access to purchase those materials. In terms of storage, I was referring to lead azide, which I have to synthesize. I use energetics to do actual work on a vacation property I own and don’t always have time to synth lead azide or other primaries. I’m also planning to try NHN.

Katie - 26-4-2020 at 19:12

I have an update. After spending 4 hours shopping on amazon, I was able to find anti-static bags, borosilicate food storage containers with air tight lids, argon gas (called “Bloxygen”), anti-static spray (permanent urethane based coating), drierite desiccant, and oxygen absorbing patches.

This is my current setup: dex. Lead azide placed in an airtight container with a large amount of drierite overnight. It’s then placed in an anti-static bag and sealed under argon with an oxygen absorbing packet. The bag is wrapped in paper to keep out light and act as a shock absorber for the bag of lead azide. This is placed in an airtight food storage container with desiccant, oxygen absorber, and in an argon environment. The container and it’s lid are first coated with the anti-static paint and the whole thing is stored in my homemade ATF compliant explosives magazine. I’ll store blasting caps in a similar manner.

It probably a little overkill but I enjoyed doing it so we’ll see how it works long term.

As a plus, the argon, desiccant, and oxygen absorbers can also be used to better preserve reagents. My diethylenetriamine actually has “store under argon” on the bottle.
Argon is heavier than air and creates an oxygen and moisture barrier over whatever it’s covering. The argon I got was in an aerosol type can, but amazon also sells large pre-filled argon gas cylinders for welding, which are probably a better value if you are going to be using a lot of argon.

XeonTheMGPony - 11-5-2020 at 04:52

I store my compounded PVA-lead azide in a stainless steel shot glass in a stainless bodied desiccator filled with calcium chloride and shielded from light.

the shot glass is kept very clean, every time I use it the edges get wiped down by a ever so slightly moist paper towel. water is bad, as it absorbs co2 then starts degrading the Lead Azide

The goal here is to ensure you and the tools are all at equal potential related to each other, ie no sparks, that is about it for ESD sensitivity!

I use industry spec 80 LA with 20% Lead styphnate mix, 150mg does the job very reliably. I use 6mm aluminium tubes

there used to be 20 grams of that compounded mix! I've gon through a lot of it. 150mg pressed azide pellet is pressed onto 500mg of pressed ETN, 10mg of pure lead styphnate is added in along with the ignition wire doped in light nitro cellulose lacquer, this coats the whole cavity in a layer of styphnated lead.

The lead styphnate is stored in pure distilled water with 30% Ethanol to aid in drying when needed, I produce that in 10 gram batches

All of that is stored in a safe due to sensitivity and toxicity.

[Edited on 11-5-2020 by XeonTheMGPony]

mackolol - 11-5-2020 at 09:09

Quote: Originally posted by XeonTheMGPony

The lead styphnate is stored in pure distilled water with 30% Ethanol to aid in drying when needed, I produce that in 10 gram batches

All of that is stored in a safe due to sensitivity and toxicity.

[Edited on 11-5-2020 by XeonTheMGPony]

I wonder how do you handle the lead styphnate when you have to use it. Besides it is said to be one of most common used initiating materials in industry, I've heard that it explodes even because of human body's electrostatic discharge so you have to hold some electrical grounding while operating it.
Is it really that unstable?

XeonTheMGPony - 11-5-2020 at 11:06

Unstable no, that sensitive yes.

I dry it on a filter paper till free flowing dry then either compound it, or use it. but only the amount I need, and bulk container goes back into the safe right away.

All my work is don on a grounded mat. you want every thing at the same potential, why I use steel containers any sparks happen away from the stuff that goes bang, and the second you touch it every thing will be at same potential.

It is amazingly sensitive to heat! Lead azide is sluggish by comparison. Well worth the effort to have IMO.

here have a 300+ page pdf, chapter 7 has priming mixtures and good data on LA

[Edited on 12-5-2020 by XeonTheMGPony]

Attachment: TM 9 1300 214 Military Explosives - Upload by Dave the Rave.pdf (1.9MB)
This file has been downloaded 637 times

mackolol - 11-5-2020 at 23:41

Quote: Originally posted by XeonTheMGPony

Unstable no, that sensitive yes.

I dry it on a filter paper till free flowing dry then either compound it, or use it. but only the amount I need, and bulk container goes back into the safe right away.

All my work is don on a grounded mat. you want every thing at the same potential, why I use steel containers any sparks happen away from the stuff that goes bang, and the second you touch it every thing will be at same potential.

It is amazingly sensitive to heat! Lead azide is sluggish by comparison. Well worth the effort to have IMO.

here have a 300+ page pdf, chapter 7 has priming mixtures and good data on LA

[Edited on 12-5-2020 by XeonTheMGPony]

So why do you prefer styphnate over just lead azide? And what for do you use it, if I may know?

Herr Haber - 12-5-2020 at 04:27

Styphnate serves as tinder when mixed with LA that has a much higher ignition temp.

If memory serves, LA ignition should be around 400 and some degrees so you "might" not set it off with a fuze (even though it's burning temp is much higher). And a mere squib ? Meh.

XeonTheMGPony - 12-5-2020 at 04:59

Quote: Originally posted by Herr Haber

Styphnate serves as tinder when mixed with LA that has a much higher ignition temp.

If memory serves, LA ignition should be around 400 and some degrees so you "might" not set it off with a fuze (even though it's burning temp is much higher). And a mere squib ? Meh.

This is indeed why, it acts as a sensitizer ensuring a strong thorough ignition of the L.A. and leads to a stronger initiation of it.

so the main azide pellet is 80% lead azide, with 20% Lead Styphnate, then topped by a dusting of the Lead Styphnate in pure form to act as tinder for the bridge wire.

But this configuration makes it just easily utilized by the old fashioned powder fuse as well, so it makes for a dynamic use cap.