Underwater AP cratermakers

[Spoz]

Hi, since I recently acquired some nice underwater blasting fuse - a rarity in australia - Ive been playing around with underwater cratermakers filled with black powder. These were fun at first but they got boring pretty quickly.

Ive been thinking about using AP as a filler for these, but I have never made any HE before. Ive been reading this forum for probably over a year now so Ive come to see the different opinions on the sensetivity of AP and I have enough knowledge to make it.

What I wanted to know was, exactly how safe would putting AP into a CO2 cartridge be? How safe is it to press - does it even need pressing - how much pressure to use? How much should I use to ensure detonation, how safe is carrying them around?

These are all questions which have stopped me from synthesising AP (I have the precursors) and yes, it is a noobish question because I am a noob. But I would rather ask knowledgable people than blow my hand off finding out the hard way. If anyone here can answer some of the above questions or give me any tips for starting out, it would really be appreciated.

Undoubtedly someone will flame me for this, but "To be old and wise you must first be young and stupid"

Edit: Forgot to mention, the fuse hole needs to be 5mm (~3/16") to accomodate the fuse, might make a difference when it comes to pressing the AP

[Stone]

Personally, I wouldn't ever put AP into a metal container, it's too unpredictable.

Pressing helps but again, unpredictable AP is not something you want to cause friction with if it's in a metal container.

Think of a pea(the green thngs you eat), then halve that... That much AP wll detonate.

Again, I wouldn't want to be anywhere near AP in a metal container let alone carry it to a test site.

If you plan to make AP, make a small amount and experiment with it in SMALL amounts with heat, friction, etc so you can see how it reacts. Then think about if you'd want that going off in your bag, pocket, or whatever.

[Spoz]

Thanks for the warning. I might still go ahead and do as you suggested by testing a small amount. Ive seen the effects of shrapnel from cratermakers, and if AP is that unpredictable then I wont take the chance.

When dealing with HEs underwater, would cardboard casings provide the same effect as a metal one, or would it seem 'deadened' as it does with low explosives?

I might have to hunt around for a more suitable explosive to use

[knowledgehungry]

If you plan to make AP, make a small amount and experiment with it in SMALL amounts with heat, friction, etc so you can see how it reacts. Then think about if you'd want that going off in your bag, pocket, or whatever.

Do not assume that your AP will act a certain way because of previous tests with it. The danger of AP is that it is not only unstable but very inconsistent one day you have to hit it with a hammar to make it go off the next day dropping a nick bag

[xyz]

SWIM has filled CO2 cannisters with AP before (using light pressing) with nothing out of the ordinary occuring. I would still advise against doing it though, but if you must, use them soon after you make them or the AP will corrode the metal casing and possibly become more sensitive.

Underwater though, the casing doesn't really matter. Use plastic (small diameter PVC or poly pipe) or waterproofed cardboard. Even above water, the casings for AP matter MUCH less than those for BP. AP will still produce a loud bang when even slightly confined by a small piece of drinking straw or a few layers of paper.

Underwater stuff is fun, well, according to SWIM anyway ;) , he also says you get bonus points for flushing small charges down public toilets.

[Stone]

Do not assume that your AP will act a certain way because of previous tests with it. The danger of AP is that it is not only unstable but very inconsistent one day you have to hit it with a hammar to make it go off the next day dropping a nick bag
Yeah, sorry. I meant test to see how violently it reacts under certain conditions so he'd reconsider using a metal casing, not to predict how it would react in the future.

[Spoz]

I think Ive been adequately persuaded to stay away from metal casings now :rolleyes:

Youd think Id have learned my lesson when I had a BP filled one go off far too close for my liking, but instead I just shifted my experiments to a more aquatic environment...

Underwater charges are indeed fun, especially when the water is nice and clear... and theres plenty of wildlife around to scare.

Just out of curiosity, what would most people here use in such a charge (less than 5-10g of explosive, detonated underwater), taking into consideration that it needs to be carried a km or so on foot? Would you consider using an unstable primary for the entire charge (that scares me...) or would you use something like APAN or even ANFO?

I have read in detail on these, but I lack any practical experience to make a decision...

[Cyclonite]

If you really want the added umph of a metal casing here’s the least hazardous was to go about it...take a pipe with 2 end caps. Drill your fuse hole in one. For your AP charge here’s what I suggest. If your dead set on straight AP then wrap it in plastic wrap a few times nice and tight with the fuse. When the time comes you can simply insert it into your shrapnel producing case with little fear of getting HE in the threads or reacting with any metals. Hardware stores sells small diameter pipes with end caps, in my option easier than an empty Co2 cart. For a added effect you can etch with a dremal a shrapnel pattern on the pipe casing, good fun. The main lesson with you want your time within a device that can kill you to be as short as possible so only insert the HE into the casing when you ready to detonate it.

[Marvin]

My own opinion is that using AP as a base charge is pretty suicidal. We are reasonably certain on this forum that AP has killed one person and we can put a name to a nolonger posting nick. Of course, he was making a lot of the stuff.

I'm unsure what I'd do in your shoes for an underwater explosive, mainly because I don't know what you have access to. I do think that being able to carry a small amount of primary explosive seperatly from the main charge of secondary is much safer.

With regard to metal casings I think you may be missing the point.

With blackpowder the bang you can get depends very much on the degree of confinement you can provide. With high explosives this (a few large critical radius mixtures excepted) is untrue.

I'd say the only use for metal casings with high explosives is for hurting people. The other thing I'd add is that if you think you know shrapnel from the blackpower explosions - you really don't know shrapnel from a HE explosion and AP is not at the soft end of nasty, it can do some very scarey things with 'soft' plastic let alone steel.

[me234]

Spoz, from a simply bias point of view, I'd say go with APPN or APAN. If you can't get a hold of some secondaries, a nice mix like one of these ought to help with sensitivity, and it'll produce a higher amount of gaseous products per weight explosive (if that journal article detailing AP's decomposition to acetone and O2 holds true for higher temp. decomposition). The dead-easiest secondary I can think of to make would either be ANFO or UN. Unfortunately both need a booster, and you may be wanting to keep this dream of yours a bit small at first.
Also, how deep is this body of water you have in mind: 'cause if it's 3 inches deep, recommending a 1Kg charge is a bit silly.
Wait, what am I saying, a 1Kg charge (or any charge for that matter) is never a silly thing, it's a fun thing...
I say go for something small, 10g sounds reasonable for a first try.
P.S. Don't scare the wild life, if they can hear something, people can hear something. I hear pigs (the wild life ones of course) have exceptional hearing too.

[Spoz]

Thankyou guys for the positive and helpful replies so far. Not having experience with HEs before, I didnt really understand how confinement affects things like the sound of the detonation.

I should be able to track down some ammonium nitrate, so I can experiment a little with APAN and ANFO. If I can get the AN I dont see why an APAN booster would be a problem, other than the small size of the charge.

As for the depth, I have anywhere from a few inches to several metres - the size of the device would dictate how deep it would be placed.

[tom haggen]

Well as said before, stay away from metal containers at all costs unless you are trying to seriously injure some one. Anyway it sounds like you are quite fascinated with under water explosions. Let’s be honest who isn’t amazed by underwater explosions? Anyway this may sound kind of newbish but what the hell. I worked with AP for quite a while specifically an AP smokeless powder composition before finding a certain property out that is a characteristic of AP putty. The stuff is mildly water proof. It relatively powerful and you can experiment with safe amounts and still enjoy your self. Anyway if you have underwater fuse you can just make some AP putty and tape a fuse to it with no water proof container needed. Remember always carry detonators and main charges in separate containers.