Some questions regarding AN / AL (For use as reactive shooting targets)

[MatCat]

Greetings, I realize there are a few threads on this subject but none really answer my specific questions.

 

First is the general AL mesh most people recommend is 300 to 600 mesh, but some people use up to 4000 mesh, what effect will mesh size have? (My assumption is that smaller size AL will equal better surface area coverage of the AN equaling a more efficient detonation, am I correct in this?)

 

Secondly I see mention in ammoral formulas of charcoal, what effect would charcoal have on the chemistry?

 

Thirdly the official tannerite brand adds zirconium and titanium, what effect does that have on the chemistry?

 

Thanks everyone, just trying to get a better grasp of the chemistry involved.

[dave321]

actually, I think if you check the patent, you will find that tannerite includes

ammonium nitrate

ammonium perchlorate,

zirconium hydride

titanium

[lloyd]

And none of this has a whit to do with fireworks.

 

Get thyself a blasting license, and play all you want!

 

Lloyd

[MatCat]

And none of this has a whit to do with fireworks.

 

Get thyself a blasting license, and play all you want!

 

Lloyd

For reactive shooting targets you do not need a license for binary.

actually, I think if you check the patent, you will find that tannerite includes

ammonium nitrate

ammonium perchlorate,

zirconium hydride

titanium

Care to explain some of the chemistry as I originally asked? Thanks.

[MatCat]

Also for the record of what the Tannerite patent contains, I have quoted the relevant section.

 

http://www.google.com/patents/US20030033952

 

 

The Ammonia Perchlorate is added to the Explosive Grade Ammonia Nitrate once the Ammonia Nitrate prills are milled into a powder of 200 mesh. The Oxidizer solution is then funneled into the target containers and the labels attached. The lids are sealed. The catalyst is bottled with 90% Explosive Grade Aluminum powder, 5% Titanium powder and 5% Zirconium.

[Mumbles]

For the record, the actual patent says differently. Check out US6848366. What you are quoting is the application, and is also inconsistent with the diagrams included, which state zirconium hydroxide.

 

As far as the chemistry you keep asking about. Charcoal helps to bring the oxygen balance closer to zero. Aluminum does the same thing. Titanium or zirconium and their respective hydrides are really there for a visual effect (sparks), and really don't affect the actual reaction much.

 

Metal particle size can be measured in one of two ways. If it's quoted in millimeter or microns, it's a measure of either the average particle size or the upper and lower bounds. It's a measure of actual particle size though. Related, but not quite the same is mesh. This is a measure of holes per linear inch of the screen through which the metal powder is graded. It's sort of a proxy for particle size. To get a measure of true particle size based upon a mesh value you have to account for wire thickness. A 4 mesh screen does not have 1/4" openings. The real size is around 0.20" actually. They only make screens so fine. Any mention of a mesh finer than 600 or so is bullshit. A 600 mesh screen with infinitely small wires has openings of 42 microns. A real 600 mesh screen has openings in the single microns. There are some suppliers, most notably disingenuous sellers on ebay, which make up theoretical mesh sizes for their products as a marketing ploy. Thus a real -600 mesh, 5 micron, or theoretical 4000 mesh particle are all essentially the same.

[MatCat]

For the record, the actual patent says differently. Check out US6848366. What you are quoting is the application, and is also inconsistent with the diagrams included, which state zirconium hydroxide.

 

As far as the chemistry you keep asking about. Charcoal helps to bring the oxygen balance closer to zero. Aluminum does the same thing. Titanium or zirconium and their respective hydrides are really there for a visual effect (sparks), and really don't affect the actual reaction much.

 

Metal particle size can be measured in one of two ways. If it's quoted in millimeter or microns, it's a measure of either the average particle size or the upper and lower bounds. It's a measure of actual particle size though. Related, but not quite the same is mesh. This is a measure of holes per linear inch of the screen through which the metal powder is graded. It's sort of a proxy for particle size. To get a measure of true particle size based upon a mesh value you have to account for wire thickness. A 4 mesh screen does not have 1/4" openings. The real size is around 0.20" actually. They only make screens so fine. Any mention of a mesh finer than 600 or so is bullshit. A 600 mesh screen with infinitely small wires has openings of 42 microns. A real 600 mesh screen has openings in the single microns. There are some suppliers, most notably disingenuous sellers on ebay, which make up theoretical mesh sizes for their products as a marketing ploy. Thus a real -600 mesh, 5 micron, or theoretical 4000 mesh particle are all essentially the same.

I see, very informative thank you! Now when you say bring the oxygen down to 0 am I correct in assuming that you mean the amount of oxygen available in relation to fuel? If so then charcoal is just another fuel like the AL is? And if so what is the difference in reaction between the two?

[Mumbles]

If you'd like to read a little more about this, I'd suggest checking out information on oxygen balance. There's a primer on wikipedia, but it's not all that complete. You have the right idea though. The more balanced the fuel and oxidizer, the better and more cleanly the composition will burn or react.

 

The biggest difference between charcoal and aluminum is the energy released by their respective oxides when they burn (heat of formation). Charcoal produces -393.5 kJ/mol, while aluminum produces −1669.8kJ/mol. On an atom to atom basis, aluminum still produces about twice the amount of energy that carbon does.

[MatCat]

 

Just wanted to show off my first attempt at my own AN / AL blend. Came out pretty good, shot it with an SKS using 7.62x39 FMJ.

[Jakenbake]

Nice. What was your source for the AN?

[MatCat]

Nice. What was your source for the AN?

Cold packs from Walmart, bought a case of 24, roughly 1/4lb in each, $16.

[Arthur]

 

... 300 to 600 mesh, but some people use up to 4000 mesh, ...

 

IMO meshes to 600 may well exist and be sieveable by home users when the material is basically spheroidal particles. Finer than that is usually sieved by special means inc suspended in an oil -methods usually beyond the home experimenter. The smaller particles are often not spheroidal and have ragged edges if viewed under an electron microscope.

[MatCat]

 

IMO meshes to 600 may well exist and be sieveable by home users when the material is basically spheroidal particles. Finer than that is usually sieved by special means inc suspended in an oil -methods usually beyond the home experimenter. The smaller particles are often not spheroidal and have ragged edges if viewed under an electron microscope.

The AL I purchased (from eBay) was advertised as 1650 mesh, or 9 micron, says it is atomized powder, certainly a very very fine powder, how sure of course if it really matches the size spec, but I did get a good boom so I am pretty happy with it . I did notice it is way lighter in color then the stuff official tannerite brand uses.

[FlaMtnBkr]

Any aluminum powder finer than about 150 mesh and you won't be able to tell much difference other than color. Also, in my experience the stuff on eBay doesn't come close to the size it claims to be unless it gives an actually manufacturer and product name. Even then it's often not the real thing. If it was really 1650 mesh it would make some decent flash powder but I would be willing to bet flash made with it doesn't even burn in smaller quantities. But exploding targets are easy to make and don't require super fine aluminum like flash powder does.

 

I make my exploding targets with 325 mesh atomized aluminum powder as there is no need for an expensive dark pyro grade aluminum. Once it is sufficiently fine to 'sensitize' the AN it doesn't matter if it is any finer. At least it doesn't make a difference that I can detect. Exploding targets detonate where as flash undergoes deflagration which means it burns really fast so a smaller particle size is important because they can burn faster. Kinda like the difference between a log and a twig in a camp fire.

 

As long as your AN is dry, your aluminum is sufficiently fine, and you are shooting a fast enough round, your targets should work fine. I've found 2700+ ft/s is about the point where they become reliable. You might get away with speeds down to 2500ish but they won't be perfectly reliable, again, in my experience.

 

Make sure you always mix them on site and always use them once mixed or destroy them. You can destroy it by simply dumping on the ground and fertilize your shoot site at the same time. Also, not all instant cold packs are AN and it seems like those are getting harder to find and most are now urea. It is also an expensive source of AN but not as expensive a source as commercial exploding targets. Make sure they are legal where you are because the sound can travel for miles and you should expect a visit by the local sheriff at some point if you make them a habit.

[MatCat]

Any aluminum powder finer than about 150 mesh and you won't be able to tell much difference other than color. Also, in my experience the stuff on eBay doesn't come close to the size it claims to be unless it gives an actually manufacturer and product name. Even then it's often not the real thing. If it was really 1650 mesh it would make some decent flash powder but I would be willing to bet flash made with it doesn't even burn in smaller quantities. But exploding targets are easy to make and don't require super fine aluminum like flash powder does.

 

I make my exploding targets with 325 mesh atomized aluminum powder as there is no need for an expensive dark pyro grade aluminum. Once it is sufficiently fine to 'sensitize' the AN it doesn't matter if it is any finer. At least it doesn't make a difference that I can detect. Exploding targets detonate where as flash undergoes deflagration which means it burns really fast so a smaller particle size is important because they can burn faster. Kinda like the difference between a log and a twig in a camp fire.

 

As long as your AN is dry, your aluminum is sufficiently fine, and you are shooting a fast enough round, your targets should work fine. I've found 2700+ ft/s is about the point where they become reliable. You might get away with speeds down to 2500ish but they won't be perfectly reliable, again, in my experience.

 

Make sure you always mix them on site and always use them once mixed or destroy them. You can destroy it by simply dumping on the ground and fertilize your shoot site at the same time. Also, not all instant cold packs are AN and it seems like those are getting harder to find and most are now urea. It is also an expensive source of AN but not as expensive a source as commercial exploding targets. Make sure they are legal where you are because the sound can travel for miles and you should expect a visit by the local sheriff at some point if you make them a habit.

Just for reference http://www.walmart.com/ip/14321213($13.99, they went on sale since I bought my last box!), will yield 6lb AN

 

Luckily I live in a very remote area, and generally the wind is blowing away from any nearby civilization. Last time I had to call the police it took them 30 min to get out here .

 

One thing I noticed is my mix is easily 2x the potency of tannerite brand, I am wondering if them adding zirconium, titanium sponge, and perchlorate slow down their mix a little, I also notice official tannerite mix seems a little less smokey too.

 

I am using an SKS so 7.62x39 round, out of the muzzle it should be roughly 2,400FPS, shooting from 50 to 100 yards away so probably not losing too much velocity, sofar I have done 3 tannerite brand, and the 1 of my own all went off no issues.

 

I am thinking of trying flash powder with this AL I have, just to experiment and see, I will report back if I do.

[pyrojig]

 

One thing I noticed is my mix is easily 2x the potency of tannerite brand, I am wondering if them adding zirconium, titanium sponge, and perchlorate slow down their mix a little, I also notice official tannerite mix seems a little less smokey too.

 

After shooting all types , and homebrews: tannerite is more reliable and sensitive than the other name brands ( and home brews for the most parts. ) . It is not a accurate statement to claim such things above , w/o proper testing equipment . I understand your excitement as to experiencing your homebrew tarrget work , but unsubstantiated statements are not a good way to compare.Sound / smoke and noise are not a fair way to gauge power.; I have shot name brand targets and winged them ( and they just caught on fire) . It is more so a good shot placement and proper activation speed of the round shot at it. Good job getting the store brand stuff to pop. as said above , it is getting harder and harder to obtain these materials .

[MatCat]

 

After shooting all types , and homebrews: tannerite is more reliable and sensitive than the other name brands ( and home brews for the most parts. ) . It is not a accurate statement to claim such things above , w/o proper testing equipment . I understand your excitement as to experiencing your homebrew tarrget work , but unsubstantiated statements are not a good way to compare.Sound / smoke and noise are not a fair way to gauge power.; I have shot name brand targets and winged them ( and they just caught on fire) . It is more so a good shot placement and proper activation speed of the round shot at it. Good job getting the store brand stuff to pop. as said above , it is getting harder and harder to obtain these materials .

I agree that the 'power' may or may not be what I said, but I AM going by sound, smoke, and effect for my claim, which honestly is what matters to me, and in that aspect it was easily 2x moreso then tannerite brand for equal weight. I figured it would be before I even did it for 2 reasons, 1 the prill size of AN from these cold packs is about 1/4th size of tannerite brand prill, and secondly the AL I got is certainly a lot finer then tannerites, I assume that the greater surface area contact is what makes it so.

[MatCat]

 

Put together 12 cold packs which turned out to be 3.37lbs, the paper bundle has the AL in it. Going to be detonating this in 2 hrs with the pictured SKS Will have video afterwards.

[MatCat]

 

This one was fantastic! I was back 100 yards and man what a fantastic shockwave that was! I had my computer recording at home 1/2 mile away, in the video I have that clip of audio that captures the boom and rattling noises of my home, amazing no one called the cops considering roughly 300 people live within rattling range haha. I won't be doing any more of this size for a while, maybe I will do 7lb on the 4th, but until then I think I will stick to 1/2 and 1lb for my general weekend noise making .

Edited January 1, 2016 by MatCat

[MatCat]

What are good additions that could add something interesting to the reaction, I realize it would probably be difficult to do without really altering the reaction, but what is possible, say for colored smoke. Like say a layer of copper oxcide on the top of the target for green?

Edited January 5, 2016 by MatCat

[Seymour]

Copper won't do much colouring in this context. Copper thermite gives off nice pink metallic copper smoke, but AN type reactive targets already seem to be pinkish from nitrogen oxides.

 

If you want "coloured smoke" my suggestion is placing powdered dye, or powdered coloured chalk dust in a container next to or near your explosive target. I bet you could do some cool things with several different colours places in arrangements around your charge

 

Note that you will probably want quite a lot to get a good effect. I'm completely guessing here, but I would want to use several times the weight of the explosive in dye/coloured powder.

 

From a special effects perspective, I feel that the addition of course Titanium, and then a decent quantity of a hydrocarbon fuel would make a good looking reactive target.

 

Of course both the fuel and the titanium add to the fire risk, which should be noted. The Ti is for igniting the dispersed fuel, and the effect from the sparks, while great on it's own, is not why I mention it.

 

Can anyone verify that coarse Titanium does indeed light up in the context of AN/Al initiated by a high kinetic energy impact? It's not something I've tried, personally... ...Yet

Edited January 5, 2016 by Seymour

[PIL]

What are good additions that could add something interesting to the reaction, I realize it would probably be difficult to do without really altering the reaction, but what is possible, say for colored smoke. Like say a layer of copper oxcide on the top of the target for green?

Copper oxide? No green smoke for sure. But you can pack some colored corn starch or talcum powder around a small salute target to create the effect you want.

[MatCat]

Fantastic idea on the chalky type substance, I will have to try that. I will also have to try and experiment with Ti/Fuel, we have been getting crazy amounts of rain lately so everything is soaked, very low fire risk right now.

[pyrojig]

Ti will indeed ignite when An/Al dets. The heat and pressure from the explosion causes ignition . It indeed is a sure way to ignite a fuel placed above the target. I saw a demo on some tests Boomer shot did.

[ThatAKguy]

Hello All,

 

This is my first post and so far I'm enjoying all the knowledge.

 

I've recently purchased some AN and AL from amazon for making binary targets.

I'm having difficulty getting a reaction.

 

I'm using 1/2 teaspoon (approx 11.33 grams of AL) for every 1/2lb of AN.

 

I've increased the mix to 22grms of AN and still no change.

 

What is the recommended minimum maximum prilled size of AN for these type tragets.

 

I'm not sure the exact AL size, but is much finer than talcum.

 

I've tried using old water bottles for containers,and zip lock bags. Is compression a contributing factor to reaction?

 

I'm a total noobie to the Pyro world so any guidance is appreciated.