Method of storing AP indefinitely?

[Spleenman]

Couldn't one use those kitchen vacuum sealer devices (The ones meant for vacuum-packing meats and other such perishables to keep air from them) to store AP? Since it's sealed off from outside air, there would be no evaporation of the AP, and plastic bags typically don't involve grinding friction when opening, so couldn't one store AP relatively safely like this? Of course, if one were to bend or crush the package, the individual crystals would rub together and... :( . Perhaps one could fabricate his detonators (Or whatever the AP is to be used for) in advance, then vacuum-seal the completed dets. Just a thought.

[Fallout85]

I always thought things volatilized faster at lower pressures...let alone near vacuum! In fact I remember an "acetone volcano" demo that involved acetone in a vacuum quickly vaporizing and forming a gaseous jet! Now I don't think that would happen with a solid but it would still be very bad. Am I wrong? :confused:

[TheBear]

Fallout85, You are entirely correct. Lowering the pressure will increase rate of evaporation.

[Spleenman]

Damn, didn't think about that. Just saw a commercial for one of those kitchen vacuum seal gadgets and though "No air=nothing for AP to evaporate into". Meh, brain fart on my part.

[Fallout85]

Now this does get the wheels rolling though...what if you pressurized the container? I'm sure even relatively thin steel or aluminium could with stand the pressures generated by a simple workshop compressor. Would ~300 psi have any significant effect on its rate of evaporation? And why stop with ordinary air? Pressurized nitrous, hydrogen, oxygen, (insert favorite) might make the explosions significantly more powerful...and prettier. ;) Pressurizing with butane, propane, or acetylene and the like are not advised though. Butane and propane would most likely act as a solvent and dissolve the ap. Acetylene doesn't like being under pressure with out a suitable solvent. I would also check to see if the gas would react with ap especially at elevated press.

[tmp]

What about storing it wet and cold ? I've noticed that CFR 49 prohibits many
materials, such as RDX and HMX, from being transported dry. Water seems to
to desensitize many explosives. Just a thought.

[Hang-Man]

Am I the only one who <b>does not</b> want to store AP? I mean, having a sensitive primary around seems to create more problems that it solves.

[MightyQuinn®]

Would the AP be able to volatize that quickly? Those sealers work fast. Once there is no air, there would be no place left in the package for the AP to re-crystallize. This is assuming that there will be no outgassing of the AP Forming pockets of gaseous material and inflating the sealed package like a balloon?

I think this is a great question really. I have visions of a sheet of AP “meatballs” all pouched up tight and cut in to individual “meatballs.” To use, simply prick the plastic with a knife, insert chosen favorite igniter and blammo.

Here comes the “but” part. Fallout85, are you saying that the will be some type of reaction taking place as soon as the vacuum is applied? There will be little time during the vacuum process for much to happen, no? I can understand this happening if you were trying to apply a vacuum, to say, a Mason jar half filled with AP (do NOT do this!) and having room left in the container for evaporated AP to collect, but in a sealed bag with NO voids? Unless……(see above) regarding gaseous output

Worst thing that strikes me about it is the “pucker” factor while the vacuum is applied and the AP is compressed to some extent.. Once sealed, I would feel better about handling them…but will NEVER feel totally safe around AP, considering what I NOW know about AP (see my results post in the AP thread (coming soon))

This is where my relative ignorance of chemistry becomes a detriment to me. Somebody set me strait, please.

_____________________________________________


Am I the only one who does not want to store AP? I mean, having a sensitive primary around seems to create more problems that it solves.

I agree Hang Man......however, it is nice to theorize about methods to give me every ounce of safety edge for storage of even the 'fresh' stuff I dream of making. :D

[mikeg]

Will cold storage work? I think one of the problems with AP is that it goes from a solid to a gas over time(it sublimes). Storing it cold might slow that process down. You may want to experiment with a small amount in case cold causes detonation.

[Fallout85]

See the thing, is I think it would actually turn in to an ap balloon as you said. Anything volatile WILL expand in a state of near vacuum...as to say how fast or how much this would happen with a volitile solid like ap, your guess is as good as mine and I'm not going to be the first try it! :p

Hang-man is probably right though...better to just not store it all. It's really not that hard to whip-up on short notice anyway. Still some interesting ideas though.

[Desmikes]

Vacuum will cause the equilibrium to shift towards gas production. Another problem is that trying to get the air out of fine dry powder often causes the powder to flow; you risk sucking AP crystals into your vacuum machine. The safest method to store AP would be to sink it in a container with distilled water via drop-wise addition of acetone, and cover it up with clear sticky plastic wrap and a rubberband.

[Boomer]

I don’t know who invented the "extremely volatile AP" ! I even read it looses half its weight in 10 days at room temperature, but this is complete BS :mad: (unless he was speaking of the dimeric form, but even that is more stable I bet).

I once stored DRY AP in a marmalade jar for a year, and it was still perfectly OK. The crystals seemed slightly larger, but there was hardly any re-sublimated stuff at the lid and the upper walls. BTW it cannot get into the screw threats, as they are outside, and the rubberised lid is sealing the jar on the rim. No way for crystals to get between something there. Cleaning the lid every month is advisable though. ;)

Now I found a much safer method: The AP is mixed with water and the slurry is stored under water in a jar in the fridge. Every 2 month I check the ph and add a drop of bicarb solution if needed. It seems the crystals do NOT sublimate under water, they do NOT get bigger with time. The smell is noticeable above the surface though, and some small crystals seem to form on the upper walls. I simply shake the glass to soak them wet before opening.

Though they are really wet, complete drying takes one hour only! Tale out a spoon full, put it on a filter, wrap it up with TP and step on it. Repeat with a new filter. Within a minute it is so dry it flashes with a “WHOOOMP”. It contains only a few percent water and could now be pressed into caps if they are left to dry before crimping fuse in. Or one hour on the oven makes the stuff bone dry if the caps are to be sealed ASAP.

Yes I said on the oven! It is spread in a very thin layer on a paper, this is placed on the biggest plate with a surface thermo coupler beneath. The oven is switched to full power for 8 seconds and left for 10 minutes. A few more times I come back to switch it on again for 4 seconds. This keeps the plate between 30 and 35C, which is harmless as any shed in Arizona will be hotter. The full power is necessary because lower settings don’t power all heating elements, possibly leaving you with one hot spot in the centre of the oven plate.

You could replace the oven with a big enough dessicator, or wait overnight at room temp, but I prefer to have AP around for one hour max before it is processed 'cause my careless GF puts her cigarettes everywhere ... :D

[matjaz]

"...wrap it up with TP and step on it. Repeat with a new filter. Within a minute it is so dry..."

Just don't land on my head when you're done. ;)

[Boomer]

When you step on it it is still quite wet, THEN the water is soaked out and into the paper and you take the foot away. You dont jump up + down on it.

Anyway the pressure per area is much smaller then when pressing caps, and there is only soft tissue around, no metal cap + hardwood dowel.

If I only need 1/2g for a cap, but FAST, I even press it in a big vice after using my body weight (wearing protection)! ;)

[Anthony]

Whether or not it is safe with AP, it doesn't exactly promote good practice for general handling of explosives!

Who here honestly needs to store AP for months or years?

It takes very little effort, and not much time to make - especially if you use concentrated H2O2. I'd make up 10-20gm every know and again when I needed caps, and kept the surplus in a shallow open dish in a cool, dark place where it won't be disturbed.

Yes, you lost some to volitisation, but not all that much.

AP doesn't need to crystalise in screw threads. If it coats the inside of the container, a sheet of crystal could form across the joint between the lid and the jar. Which you will shear when you twist the lid off. An accidental explosion might not be very likely, but you have to be lucky every time to keep your hands, you only have to be unlucky once.

All this effort of vacuum packaging seems a lot of effort for lowly AP. Perhaps it would be better invested in other areas?

Also, I wouldn't make a cap with damp AP. I'd be worried about them not drying out fully, leaving a damp core, leading to a dud. Do you dry the loaded caps on the oven? How do you makes sure hot spots don't develop inside? A loose, thinly spread powder is easy to manage.

Do you remove the AP/caps from the oven before giving it another 4 second blast of heat?

You mentioned crimping fuses into caps, what is the design of your caps like, and is this process safe?

[Boomer]

“Who here honestly needs to store AP for months or years?”

It is not so much about yearS, but several people here seem to believe it gets incredibly dangerous after 1 week. This is BS, even if the crystals get slightly bigger (maybe more so in hot climate, but who has no fridge?), you can dissolve them in acetone , dump in water and viola – they are much smaller again. Plus, you can re-neutralise if needed. :)

“… every know and again when I needed caps”

I need them every second weekend. Even if AP is easy, I don’t want to spend 2-3 hours 25 times a year when the time could be used better (e.g. improving my EBW B-Box :D ).

“Do you dry the loaded caps on the oven?”

Surely not, they all have a 2g booster of MHN or PETN. They belong in a dessicator, this should dry them up through the whole mass. Anyway, it was just an idea, I also press them dry (if only to save time).

“Do you remove the AP from the oven before giving it another 4 second blast of heat?”

No, the thermal lag is so great the surface reaches its maximum temperature about half a minute after the 4-second blast. I am currently designing a kind of hot plate (without stirrer), thermostat controlled. It will have a 1’x1’x1/4” aluminium plate with the sensor inside the plate, heating elements below and electronic power control to within +/- 1C. We build similar controls in the company, I will just have to modify one and build the plate.

“You mentioned crimping fuses into caps, …”

I was referring to others, I have no visco and nearly always use electric caps. My standard cap is made from a nickel plated brass tube, closed at the bottom and made from one part. They are 9mm inner diameter, 45mm long. 1g MHN is pressed in at 20000 PSI using a vice, giving a density of 1.6. Another ½ g is pressed on top at 1500 PSI to density 1.3, then comes ½ g MHN/AP mix hand pressed, and a little AP surrounding the Xmas bulb igniter (3x4mm micro-bulbs). Some tissue is put on top around the cable to keep the AP inside and fix the cable, leaving space for some epoxy seal. They are absolutely air/water tight and store at least 2-3 month.

IF I DO use fused caps, I drill a small hole in the cap bottom, glue china (cracker) fuse in and load in reverse order. The disadvantage is you cannot press the booster charge as hard because AP is below it, and the cap might break if not suspended from all sides. :(

“Which you will shear when you twist the lid off”

The same is true for the much praised film canister. That is why I shake the glass before, wetting the crystals at the joint.

The must important reason to store AP is safety! Yes I said safety, because I strongly believe that a glass of dripping wet AP is no threat at all, you can probably put a cigarette out in it.
The preparation of AP is safe until the drying stage. If you don’t dry it but put it in lots of water after neutralising, I cannot see a danger at all. Now instead if drying a month’s supply, you make 12 times as much, but keep it wet all year. You only take out the immediate need, a few gram max.

You save the time to prepare lots of batches, you know it is always from the same batch, and – most important – you never have more than a few gram around dry, and that only for 1-2 hours!

[kingspaz]

boomer, heat drying AP, whether for a few seconds or not is not an ideal way. the best way is to use a fan assisted oven. then turn it to its lowest setting. this *should* be room temperature but because the oven is on the fan still blows and dries the AP like clothes on a line. this will take longer but is a much safer way to dry the AP.

in light of recent posts i think you should also remember not to get over confident and not forget to respect AP.

[Evan007]

Why you would need to store AP indefinately is beyond me, but I suppose if you had to store it, I just sticking it in water and putting it in the fridge would be your best bet.

I thought for a moment Freezing the AP in Water might be the go, but then the AP would settle to the bottom during freezing, and then there would be a plain old block of DRY AP at the bottom of a container. The water would just be a solid, confining and compressing on top of our AP.
If your pulling a large block of ice out of the freezer, would you like high explosive on the bottom of it, vulnerable to every bump on the table, drop on the floor.......
Hey, it probably wouldnt detonate even if you dropped that block on concrete, but its not something I would bet body parts on.

If you are storing AP Indefinately, Think about what you are doing.

If you are still storing AP indefinately, you haven't thought long enough.

[vulture]

People who are really into a way for storing AP for long periods of time are usually the people that use AP as the base charge.

Murphy's law will get them eventually, don't worry.

[tom haggen]

I don't even like keeping my AP putty for longer than 2 weeks.

[FrankRizzo]

I shudder when I realize the cavalier attitude that many members of this forum posses. DO NOT advocate drying AP in an oven. If you're that hurried and careless about your experimentation, I suggest you find another hobby. Conventional oven thermostats are not sensitive enough to maintain an even temperature throughout the unit. A localized hot spot could cause the detonation of the surrounding wet material. Remember too, that the heating coils that are above and below are MUCH warmer that the surrounding air. If just a tiny bit were to fall or blow onto them, hell would surely ensue. You have all the WRONG conditions....it's only a matter of time.

No, the thermal lag is so great the surface reaches its maximum temperature about half a minute after the 4-second blast. I am currently designing a kind of hot plate (without stirrer), thermostat controlled. It will have a 1’x1’x1/4” aluminium plate with the sensor inside the plate, heating elements below and electronic power control to within +/- 1C. We build similar controls in the company, I will just have to modify one and build the plate.

Great idea......:(

Take a look at this thread (AP under a DESK LAMP detonates unexpectedly):
http://www.roguesci.org/theforum/showthread.php?t=314

If you want to dry it out, just use an empty ice cream pail and some Damp-Rid dessicant.

AP is really not the dragon that some people make it out to be. You do however, have to RESPECT it.

[Boomer]

kingspaz, vulture, all:

I DO respect AP, and never even considered it as a base charge. In fact I treat it as if it would explode every moment if dry! You only cannot do so once it is in the cap, and this is in the charge ....

The biggest amount I ever handle (unless dripping wet) is ONE spoon full, and that is kept away from my hands by gripping the paper at the edges and taking a spatula per cap. It is left on the paper until used up, or any surplus is put back under water.

I don’t even fill the caps completely with AP, they are the compound type with only ½ g AP as a primary. The cap press is remote of course.

And I would not call 30-35 degree C HEAT drying. This is lower than the ambient in some countries. Plus, the amount I have on the oven is so small and so thinly spread that I would not mind much if it detonated, as I wear ear protection in addition to goggles. And in such a thin layer I guess it would only flash anyway, but you never know.

P.S. I had already seen the photos of the desk, that was 20 times the amount I would handle dry!
This is exactly why I make 200g in one batch, and keep it under lots of water at all times (ok, under dilute acid and bicarb during manufacture). I bet drying 50 g every 2 month is more danger than drying 2-3 g every few days. BTW the oven is just to cut the time down I have it around dry to under one hour. If you press it out well it also dries at room temperature over night.

[Guerilla]

I remember reading how somebody once had his oven (and kitchen) devastated after a spark from the thermostat ignited an ap batch that was drying in it. I wouldn't dry any primary in oven just for time's sake, but hey you know the risks..

[chris S]

I have to agree with Boomer: I also don't know where all this 'evaporation/deterioration/not able to store AP' story came from.

I also had never any problems at all, even with AP over a year old. It detonates nicely and initiates even more nicely the main charge. Certainly when it's in a closed detonator.

But I had also some dry AP stored in a closed plastic bag, and when used and pressed into a detonator, it functioned perfectly. And that batch was also over a year old I think.

I still have some dets manufactured in 1997, I'll bet they will work just fine, but I'm not longer 'practisicing' (but I'm thinking to picking it up again. I need a new hobby...)

Anyway, must say that I always use HCl, and wash endlessly and dry long. The big advantance of HCl obviously being that it evaporates and leaves no acidic residue.

[chembio]

A possible method of storing AP for transportation:

Store the AP in small containers (pill boxes etc.) and seal the containers.
Fill the bottom of a slightly larger container with a viscous fluid (slow-hardening glue, cooking oil, maybe KY jelly?)
Carefully place the AP-filled container in the viscous fluid.
Close the larger container.

Please note that the AP-filled container would have to be suspended (not touching the larger container's base) and yet still have its bottom part immersed in the viscous fluid.

Will post up pics soon. I've made the stuff mentioned above but not the AP :D

[Boomer]

Just a little update now this thread is bumped:

First of all the crystals DO grow even under water, but not that fast. In fact I noticed after 2 years. That original batch was 4 years old and still fine this new year.

I moved to storing in solution though: Crash in water, filter, press dry, oven-dry (yes half a gram thinly spread on paper), assemble, done. One hour max. Never handle over a gram, never touch it directly, and never hold the cap when pressing.

Another important point is small amounts, I used to use half a gram, but 100-200mg is more than enough for a cap with 1g of solid nitric ester base charge. Why handle more at a time?

Finally, after a house search by police investigators (after a fire in the living romm - of all rooms!), I had to clean my flat. They must have seen the dozends of jam jars with powders, and dozends of acid/solvent/... bottles, but did not care and left after telling me to "smoke more carefull".

Later I feared they only went to get a search warant to be able to use the evidence, so got rid of everything but OTC chems. Small HE samples and some dual-use precursors are stored elsewhere.

Sad but this is my long vacation now - loosing fingers did not stop me but the pigs did. Maybe I'm back some day.