Scabbling

[nbk2000]

"Scabbling" is where a thin layer of explosive is painted onto a surface and then detonated. The shock causes fracturing and spalling of a thin layer of the surface the explosive was painted on.

In a patent (6438191) I read about this technique, RDX is mixed with shellac, and thinned with acetone. This mix is then sprayed onto concrete till a 1.5mm thick layer is layed down. This is then detonated. The resulting shockwave blows off a layer of reinforced concrete several centimeters in thickness.

It doesn't damage the structural integretity of the concrete support or wall, but it DOES blow walnut sized chunks of concrete at speed in what ever direction the wall is facing. <img border="0" title="" alt="[Wink]" src="wink.gif" />

Some ideas that come to mind is to paint a wall in advanced as a sort of "stealth" claymore. The layer can be as thin as a half a millimeter (0.5mm) and still be exploded. At these thin of a layer, it's possible for the layer to be transparent, thus it could be painted onto glass windows at night, then exploded during the day, spraying the occupants with glass shards.

Or, for instance, an entrance way could have a wall painted in anticipation of ambushing a target. Or, a parking garage space could be primed to blow out a parked vehicles tires (like a mine) to prevent escape.

Many ideas come to mind as to what you could do with a transparent explosive layer that uses on site materials as shrapnel.

I wonder if AP could be used instead? The patent mentioned use of silver acetylide in prior art for the same purpose. AP might not have the brisance needed though...

<small>[ October 20, 2002, 04:06 AM: Message edited by: nbk2000 ]</small>

[Korfaction]

It could be a good way to mine some stuffs, without the problems of sticking a bomb or whatever, thus being very discreet.

But I see a few problems with that:
- Do you know the power of 0.5 mm of HE on a wall ?
- Do you think it would be still powerful enough once mixed with stuffs to stay on the wall ?

In terms of damages, I doubt that it may be really efficient (I haven't tried though...). Or on a wide surface? In a hall/corridor, painted on every wall for the guy to be at the center of the shrapnel projections.
I can see many applications too...

Another question: in the patent it's said that it would be used to destroy a layer of a wall or a surface for any purposes. I'm wondering then how do they paint it to have the explosion destroy the wall and not just be pushed away ? And shrapnels are not mentionned ?

[nbk2000]

While the power of a .5mm layer of explosive would be minimal, it makes up for it in surface area. Also, .5mm is the minimum explodeable thickness, not the optimum thickness for the perverted use.

For instance, explosive weights of 1 to 10 pounds per square meter are possible. A pound of RDX, regardless of thickness, is going to fuck someone up if they're near it at the time it explodes.

Also, concrete is hard...but also brittle. The shock from the explosive goes through the concrete and reflects off the rebar and such within, the reflections then hit the surface and spall off the concrete the explosive was original in contact with.

As for shrapnel, no, the patent doesn't discuss that because it's so obvious a hazard that they feel those "skilled in the arts" don't need to be told that. It's obvious, isn't it? Large chunks of concrete are broken off using high explosives...they aren't going to just sit there, now are they? No. They're going to fly off at speed.

It'll explode just fine, even mixed with shellac, because it's going to dry out into a film that more than 90% explosive.

[vulture]

With a layer of Al paint over it, it could maybe even burn the victim close to the wall or create an FAE effect after the explosion. But maybe the dust created by the blast would interfere with that.

With a sensitive explosive this could even serve as reactive armor, or be used for blowing out doors.

Suddenly moving objects at high speed opposite to the direction the explosive is facing might also be interesting.

And of course, last but not least, alot of pranks come to mind! :D

<small>[ October 20, 2002, 04:27 PM: Message edited by: vulture ]</small>

[nbk2000]

I can envision a ceramic vase made from pre-formed cubes bound together in a matrix, with one half of the vase painted with an scabbling layer.

When detonated, the vase shatters into the cubes, which then fly out like shrapnel from a claymore. :)

Or, line the inside of the vase with scabbling paint, then you've got an omnidirectional device. :D

Wonder, what would an ashtray made from compressed RDX powder and coated with scabbling do when a hot ember was ground out in it? <img border="0" title="" alt="[Wink]" src="wink.gif" /> That's one way to quit smoking. :p

[mongo blongo]

I imagine something like Lead Azide would be good for this. Since it will be able to make the D to D transition without confinement you would not need a detonator. Maybe a mixture of Lead Azide and a brisant secondary HE like RDX could be a possibility.

[Spudkilla]

The only major problem I see here is the time it would take to cover a portion or the whole wall efficently. You would have to have time to prepare, and do it in a place where pesky people wouldn't ask you questions. The only place I see this happening is maybe under a bridge, or in your own home, but neither of those places is to useful for much of anything, unless as a denfense measure if you get stormed by the SSSWAT Team.

You could maybe dress in handy man clothes, and get a paint spray, but the thickness of the explosive would easily clog up the sprayer. Hell, a a mix of stain and paint even clogs up paint sprayers. If you don't have a good sprayer, or a bottle of acetone handy, I would suggest not using one.

Another matter I really haven't seen discussed, how would you set a secondary explosive off while its on a while? Maybe a cap located in a lightswitch or electrical wall outlet.

That gets me thinking, you could make an exploding trap. Wire the cap to the switch, and when they go to turn the light on, it completes the circuit, ignites the cap, which detonates the wall. Think if you got the whole room covered!

[nbk2000]

Commercial HVLP (High Volume, Low Pressure) sprayers are used by the pros.

Besides, who's to say some vandals won't spray paint graffiti on a wall that some painter (you) will have to "paint" <img border="0" title="" alt="[Wink]" src="wink.gif" /> over. :D

That's your cover.

[spydamonkee]

the idea with the light switch as a trigger to all four walls, ceiling & even the floor sound pretty damn lethal

imagine being in a room that is basically an explosive cube

oh yea dont forget the door too, could use the door handle as the trigger

[vulture]

If you want to get rid of someone, spray his cars brakediscs with a pressure sensitive explosive....

[spydamonkee]

spraying someones diskbrakes with a pressure sensitive explosive would not garuntee to get rid of the target, would give them one hell of a fright when it went off though then they would have no brakes adding to the mayhem

[kingspaz]

what about spraying his break discs with oil?

[vulture]

Gotta love that simple but wicked idea of you kingspaz.. :D
But I think it will evaporate or get driven of by the centrifugal force when the wheels are turning.

[powdermunkey]

Riceboyz hot Jap car + WD-40 on exposed eleet brake disks= Kerunch...

[FUTI]

I wouldn't oil the disk, but the brake plates instead (things that are pressed on the spining disk during brakeing). It would take more oil for it, but no centrifugal force can remove it. The reactive armor idea kick ass!:) As for Al paint I'm not so sure it would work that easy but it is something worth trying.

[A-BOMB]

I just tried something like this a few days ago. I took a halloween pumpkin egg ball thing(think like an easter egg except round not egg shaped) and filled it with AN/lamp oil, Then "painted" a mix of acetone/NC&TCAP on the outside to about 3-4mm thick and then it dry. After it was dry I misted it with acetone and rolled it in the compisition from some old rifle primers(I think lead styenalate{sp?}). That unit did some rather good damage to the ground where it impacted. Also it sounded and felt like the AN detonated much more powerfully, like if it was a nitro explosive rather than AN. Maybe it was all the AN being detonated simultaneously by the TCAP/NC on the outside? Or maybe the AN was compressed to a type of "critial mass" not unlike the core of a implosion "FatMan" type a-bomb, before detonation?

[Jacks Complete]

I can see some great uses for this...

You want a simple ambush to take out 20 enemy troops wearing body armour and helmets? Spray the road the night (or week) before, then trip it using whatever you want when they are all standing on it. That's 20 fewer guys right away. Use a few landmines at either end, under the typical cover spots, so the first team walk past them (low threat) but the backup team (high threat, so moving from cover to cover) set them off. Gives the medivac team something extra to think about, and ensures few more issues for those with no legs...

Get a few idiots for Allah (or a telesniper) and you would get a very high ROI.

Combine the "paint" with a layer of supressant such as foam or dust, and it might even be possible to have multiple charges. Another trick might be to have several areas of explosive, wired to different triggers, so getting one large group with the first blast, then anyone escaping/aiding with the second.

[furdog]

Great ideas! I have made some crude APM “Anti Personnel Mines” with a great deal of luck, also claymores, trip devices that use various detonators.

The best is the APM using a re-freezable ice pack cutting the top open and then boring a 3/16 hole in both sides. The taking a hollow steel pipe 3/16 or so and making a firing pin to fit inside the pipe along with a spring behind it. Place a 22 blank in the other end along with powder.

Then mount this between the 2 outer holes. Place a string on each end to the firing pin and run it out both ends. Now the best way is to bend a metal plate into one side of the ice pack to allow the pellets to go forward not out both sides.

Now you can fill the bottom with Black powder or what ever you choose. Do it in layers like powder, 000 buckshot etc... now cap the top off with JB weld .

I will tell you”be careful as hell when playing with this until you put some sort of a disarming pin on the outside of the pull
string. "Because if you let go of the string your not going to be around to find out what happens "

The simplest way to do this is by placing round key ring through a shaft with a groove just enough to catch without going off, leaving a way to remove it when you arm the device. I do have some blueprints on paper I would have to put on PDF not sure how to do that.

I have used these with great effectiveness with wild hogs. Awesome sight to see one get shredded to bits.