Sciencemadness Discussion Board - SC - Shaped Charge liner, glass

SC - Shaped Charge liner, glass

Fantasma4500 - 20-1-2014 at 08:43

my question is kinda hard to sum up in one sentence, it would look weird
anyhow here it goes
when i walk around i spot everything laying around, and happened to come by a wine bottle which i recall having a dented upwards bottom
and its made of glass -- ofcourse

so i decided to wrap it in plastic bags and some cloth and smack the side in on it to try to get the bottom of the bottle free
i realised after picking the quite sturdy bottom out that it had a clear crack in it..

http://puu.sh/6rKam.JPG

http://puu.sh/6rKbs.JPG

http://puu.sh/6rKcL.JPG

the piece is approx 6cm wide and 2cm tall (measuring from 10 to 12)
i know it might take a decent load to get this turned into a SC

main question however is..
will this function even tho it has a crack or will it completely ruin it all? just get blown apart and form no plasma?

assuming a mixture of ETN and NC wettened with acetone just before use to form a gel that can easily take up shock and should have decent performance

assuming the shape is useful for a SC, ofcourse

VladimirLem - 20-1-2014 at 10:14

Quote: Originally posted by Antiswat

my question is kinda hard to sum up in one sentence, it would look weird
anyhow here it goes
when i walk around i spot everything laying around, and happened to come by a wine bottle which i recall having a dented upwards bottom
and its made of glass -- ofcourse

so i decided to wrap it in plastic bags and some cloth and smack the side in on it to try to get the bottom of the bottle free
i realised after picking the quite sturdy bottom out that it had a clear crack in it..

http://puu.sh/6rKam.JPG

http://puu.sh/6rKbs.JPG

http://puu.sh/6rKcL.JPG

the piece is approx 6cm wide and 2cm tall (measuring from 10 to 12)
i know it might take a decent load to get this turned into a SC

main question however is..
will this function even tho it has a crack or will it completely ruin it all? just get blown apart and form no plasma?

assuming a mixture of ETN and NC wettened with acetone just before use to form a gel that can easily take up shock and should have decent performance

assuming the shape is useful for a SC, ofcourse

oh jesus...
IF you take a very strong explosive (EDGN, ETN<

it will work...but you should ask youself about the definition of "work" that piece of shit is definitifly too thick walled and the angle is so damn fucked up, i wouldnt even give it a try with C4 and would instead just press a (50dagree shaped cone) space in the explosive and would get better results...

buy some martini-glass...they are good (wall thickness and angle) and also work with low-performace explosives like ANNM...

Gargamel - 20-1-2014 at 13:09

This is shit.

Take a new bottle and use a gas torch with a concentrated blue flame.
And prepare a bucket with cold water.
Draw a line where you want the cut, point the flame only on that point and turn the bottle steadily.

After some time, quickly put the bottle in the bucket and knock it against the walls, or just shake it violently in the water.
Ping - you got a round cut.

I used five bottles and succeeded with 3.

NeonPulse - 20-1-2014 at 13:28

To get mine off I used one of them glass shattering hammers, you know the ones at the back of the bus by the window, chipped away excessive glass and used that. Works well with 200g ANNM on a steel tube. Plastic tube left a large pressed glass plug in the hole

roXefeller - 20-1-2014 at 14:49

Some of the demonstrations of that improvised shape gave something like 3 CD's of penetration through mild steel. The military ones do close to 7 CD's through ballistic steel. Glass is not the greatest material since it become particulate. I like the martini glass idea. You can also find ornamental copper bowls online.

Turner - 20-1-2014 at 19:07

I would say you would have more of an explosive formed penetrator. Probably wouldn't go through as much steel, but give a bigger hold and more like a slug rather than a jet. I have always looked at the bottom of a wine bottle as a possible shaped charge. I hope sometime I stumble across a nice uniform copper cone.

Ral123 - 20-1-2014 at 23:24

This guy has failed with somewhat decent setup. You wont results with garbage, initiated with garbage. Go ahead, waste 80g ETN.
http://www.youtube.com/watch?v=jU3TIpoMQN4

Fantasma4500 - 21-1-2014 at 11:07

damn.. yes i did suppose i would need quite the charge for it to work, martini glass i did consider, but i would need something alike a sandpaper machine (supposing you know im talking about band-sandpaper machine)
i tried searching for smaller martini glass, and actually heard norwegians use martini glass alot, although there sadly arent any small martini glass around

about making holes etc in glass i ofcourse happen to know some around my age which ofcourse gets creative when they need a bong, yes that what drives young people today.. they managed to make hole in a glass bottle with a metal working tool
http://puu.sh/6sP2x.jpg
dont know name for it, basically a somewhat sharp tool used to scratching metal plates to draw persistent lines for cutting and what not, very carefully hitting it to take chip by chip of glass off it

i also had an very heat resistant glass bottle, original coca cola which i dumped strands of rocket candy into lit, one time it cracked and i picked it up to take a closer look, as i put it down the bottom came right off, same thing happened with a beer bottle i did same thing to, although there might be a chance of having the bottom crack?
size might be a problem for SC as most of us doesnt want to start out with a 500g charge, possibly smaller wine bottles could be found?

i mean, for making a copper cone you would need either to bend a cut plate of copper then weld with TIG (assuming its possible to copper-weld?) or heat a plate of copper followed by hammering to fit a former made of iron etc

perhaps, if there could be made a coating of copper on something that would easily slide off, then it could be heated very violently with a torch of some sort, then be pushed off when throughly heated and melted together?

Ral123 - 21-1-2014 at 12:52

From a thin sheet of copper, you can easily make a circle, then cut out a segment and fold a funnel. It can be soldered with tin. The funnel can be quite thin and light. The charge can be with bigger diameter then the cone, with something dense and heavy for confinement. No empty spaces like on the video, where the volume is not well filled.

roXefeller - 21-1-2014 at 16:10

Copper can be TIG welded, but its very finnicky. You're dealing with geometry and material with a Biot number that indicates isothermal response... the heat is drawn away rapidly. When it gets to temperature, the puddle will be large. A little skill and practice will get it to work.

Will the solder trick leave an asymmetry that has poor jets forming?

Pard - 21-1-2014 at 16:26

Perhaps buy cheap martini drink glass and use dremel or cut off the stem. The stem is so thin it would not be a difficulty feat I think.

How is it that glass can work as a shaped charge? Copper makes sense to me but not glass. I can't imagine the explosive wuold heat it enough to become like molten as copper. Is it just the way the force is forced into a small area?

Metacelsus - 21-1-2014 at 17:48

A shaped charge just means that the shockwave is focused (usually by having a conical cavity in the explosive). This is different than an explosively formed penetrator, which actually shoots a jet of material.

Turner - 21-1-2014 at 18:24

Actually, Cheddite Cheese, a shaped charge (usually) produces an explosively formed penetrator which is the actual penetrating material.

When someone says shaped charge, you pretty much know what they mean.

Although you can make an indent in piece of explosives and call it a shaped charge (munroe effect).

Also, explosives do not melt the copper from heat in a SC, but since the copper is under so much pressure (kilo bar well into the 200-300 range) it behaves like a fluid., Same thing for glass.

NeonPulse - 21-1-2014 at 20:56

I have a couple of videos that show the performance of the wine bottle bottoms as liners, one used plastic tube and another with steel tubing as the casing fro the charge.
http://www.youtube.com/watch?v=RW1COESSJpI&feature=c4-ov... and
http://www.youtube.com/watch?v=AKll8udGswI&list=UUYoGL6L...
As expected the steel gave much better penetration. overall i think the wine bottle bottoms performed quite well, better than i expected anyway. give them a go. you wont be disapointed.

Bot0nist - 21-1-2014 at 21:25

There was a thread made a while back by a member who electro plated copper liners onto an aluminum fence post cap that were near perfectly shaped, and IIRC, his tests were very successful. Many older members found this technique revolutionary as a cheap and novel way to prepare copper liners ESP shaped charges without metal machining tools. Just UTFSE, Im sure you will find it. It is a great read. Highly recomended.

Ral123 - 21-1-2014 at 23:11

Quote: Originally posted by NeonPulse

I have a couple of videos that show the performance of the wine bottle bottoms as liners, one used plastic tube and another with steel tubing as the casing fro the charge.
http://www.youtube.com/watch?v=RW1COESSJpI&feature=c4-ov... and
http://www.youtube.com/watch?v=AKll8udGswI&list=UUYoGL6L...
As expected the steel gave much better penetration. overall i think the wine bottle bottoms performed quite well, better than i expected anyway. give them a go. you wont be disapointed.

Good ones, I like how PGDN preforms good, for it's energy density.
Years ago I've soldered copper sheets and tin to make cute model fuel tanks. I admit, the cone won't be perfect. How about a small light cone(may be aluminium), with diameter smaller then the charge diameter and big amounts of cheap material like UN/EGDN dynamite. May be reduced standoff distance. I'm convinced some penetration can be achieved even with cheap material.

Pard - 22-1-2014 at 03:09

Quote: Originally posted by Turner

Actually, Cheddite Cheese, a shaped charge (usually) produces an explosively formed penetrator which is the actual penetrating material.

When someone says shaped charge, you pretty much know what they mean.

Although you can make an indent in piece of explosives and call it a shaped charge (munroe effect).

Also, explosives do not melt the copper from heat in a SC, but since the copper is under so much pressure (kilo bar well into the 200-300 range) it behaves like a fluid., Same thing for glass.

Thanks, I'd been wondering. Can they tell me how the stand off distance is figured?

Fantasma4500 - 22-1-2014 at 08:16

Ral123: yes that is most likely gonna work, its all about how simple it can be done with decent efficiency, but as stated just below by roXefeller.. wouldnt the shape of the plasma be slightly affected, and possible be shooting slightly sideways etc? anyways, TIG welding sheet metal is something i find near impossible, had a go with approx 0.05mm stainless steel (unknown alloy, very shiny) and it has a much higher melting point than copper, the problem would be that much greater control would be needed, perhaps do-able if copper plates were pressed to overlap each other..?

but yeah Pard.. a dremel should be abit cheaper than a huge sandpaper band machine.. however now i think about it, if you could simply crack it off from the ~45* cone then the top would probably not matter than much

but yes, in amateur chemistry/energetics there is usually referred to formed penetrators when talking about SC's

i think ive been through all your videos, NeonPulse.. hard to remember who tested what tho, i think this was perhaps one of the things that backed up my idea of a wine bottle bottom being useful for SC, although the ones you found has much more desirable shapes, they are alot taller
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Obu...
like this one, alot longer than what the average amateur can get a hold of (:
infact i suppose you would get alot greater efficiency if you had the plates as one solid lump of metal, i somehow managed to discuss SC's with my class' technology teacher who happens to have worked at a place where they make high tech military equipment, and we talked about how it is needed to have plates seperated from each other to be efficient at withstanding SC's, even if i wanted to i wouldnt be able to think back on how we got onto the topic of SC's

Bot0nist yes i can imagine how the aluminium could then be dissolved away with something alike HCl, that would be quite possible... aluminium foil can be formed into something nearly as hard as solid aluminium, ill try to search for it, sounds like something that became forgotten knowledge?!

actually... can anybody explain me why its never seen that iron is used? is this something about the fourth state of matter that im absolutely blank on or is it simply the metallic properties disallowing iron or perhaps even other materials alike lead to be used?
lead could be pressed without much force into a cone..

edit:
10 fingers club shows how to use FMJ bullets as liners
could the potentially not so smoothly formed copper cone be dipped in electroplating solution rather than soldering?
a person in another SC thread asked why not use entire bottle, good question.. it would allow the use of HNO3 / NM without having to consider its etching properties
still wonder if aluminium foil might somehow be useful, lead could be plated on to create a H2SO4 proof coating / cone shaper better than just aluminium foil?

[Edited on 22-1-2014 by Antiswat]

Ral123 - 22-1-2014 at 08:26

I have the feeling that if the mass of the energetic material and tamping is much greater then the weight of the cone, you can get away with cone inperfections and zero standoff distance. But you have to watch out for inconsistency in the material. No powders.
For now I'd recommend you to make a nice linear shaped charge, with high power material, good (inertial)confinement and fine linear material.

VladimirLem - 22-1-2014 at 10:18

Quote: Originally posted by Antiswat

damn.. yes i did suppose i would need quite the charge for it to work, martini glass i did consider, but i would need something alike a sandpaper machine (supposing you know im talking about band-sandpaper machine)
i tried searching for smaller martini glass, and actually heard norwegians use martini glass alot, although there sadly arent any small martini glass around

uh wat?

how about this

doesnt looks as nice as more "professionhal" shaped charges, but it will give good results...

roXefeller - 22-1-2014 at 17:57

The developers actually try different materials for their effectiveness. Aluminum cones are used for concrete targets. Copper is used for its malleable, flowing properties at temperatures far from melting. It flows really nicely and so it forms the EFP/jet effectively. This is exploited in the wrought copper industries. They also use the property to lathe swage copper liners for SC purposes. This was described on the other SC thread. The glass liners don't deform as well, they tend to break apart further into particulate.

Bot0nist - 22-1-2014 at 18:52

Atiswat, the copper cone came right off the Al fence post top, and it was reused, IIRC. Try and find the thread, some really good tips on electroplating in it. He got an nice evenly formed liner too, if memory serves.

Edit: Here you go. I UTFSE for ya. A good read. Check it out.

http://www.sciencemadness.org/talk/viewthread.php?tid=14093&...

[Edited on 23-1-2014 by Bot0nist]

NeonPulse - 22-1-2014 at 19:30

as far as linear SC goes does anyone know how much stand off is needed in relation to the depth and width of the liner? A quick search turned up not alot. i read 0 standoff was recommended by someone but also the internal height of the liner was used as standoff distance im not too sure and i only have enough HE prepped for one decent go at it. failing that i guess its back to the lab for a few hours- its getting harder these days to get a few spare hours.... also i am going to give the electroforming liners a shot, they look like are well worth the trouble for the time spent.

Dornier 335A - 23-1-2014 at 07:59

Quote: Originally posted by VladimirLem

how about this

doesnt looks as nice as more "professionhal" shaped charges, but it will give good results...

That setup works well, as demonstrated by Boomboom314159:
http://www.youtube.com/watch?v=7ZN0-bW9esA

Ral123 - 23-1-2014 at 09:09

I can't get an idea of the damage. Also, if the sand was wet, the damage would've been much better. At these pressures the dry sand would be much more compressible.

Fantasma4500 - 23-1-2014 at 12:22

indeed.. actually another thing...
i recall this guy on youtube called ''iwasapenny'', hes not there, however he showed that an standard american penny could be made into a cone-ish shape with just approx 0.1g of HE, not sure if it was AP, or what it was? it was a primary of some sort, perhaps 1g? doubtful tho...

i suppose this little dented copper plate (aka damaged penny) could be used for a small SC?

infact, if you did not break off the thin glass piece below the cone of a martini glass, wouldnt that work anyways? i suppose you would need a stronger charge to add up with the laziness although..

i suppose that if CLAY could be used as a former for the SC (i recall having seen thread on copper electroplating a clam shell on here) it would be brilliant, as not many have a lathe or can get hands on a perfect cone of aluminium, supposing it would also require a power supply that would be adjustable, definately do-able..
perhaps if someone got a way to make liners somehow, perhaps stack 10 and sell them for interested fellow members?
incase it could be misunderstood -- i would only be interested in small homemade experimental, less than 20g, but im quite sure there would be a small desire for buyable copper cones?

last thing: yes Ral123.. i thought about that adding water would increase efficiency alot, as in water added to sand.. but what about something with higher viscocity? perhaps gasoline with styrofoam dissolved in it? would probably add a neat fireball aswell, in which we all no matter how much we imply we dont would all enjoy to see, even me.. (: