Betchur bippie. Did this a couple of times with smallish party balloons. Then got to thinking about even the remote possibility of static electric discharge while inflating. Didn't do it again.
Were I to do it again, I'd want a remote fill, i.e. one gas at a time through long -- no, no, longer than that, Jack -- tubes,
There was at one time a Japanese company selling gear for small scale farming that had (IIRC) a Bird Scarer Boom, a carbide & water canon, battery-ignited every minute or so.
There used to be a blacksmith shop in Blockhouse, NS, in a building formerly soemthing much more prestigious, judging from its plastered catherdral ceiling. They had an oxy tank on a dolly with a 5' tall acet generator. You know, with the mechanical gadget at the top to let in more carbide when the telescoping tank top dropped.
I asked the smith, "Isn't that thing kinda dangerous?" He points at the ceiling. I look up to see a big starburst of soot on the high ceiling. "She goes off once in a while", say he. Nerves of steel, I guess, or significant blood alcohol.
My understanding was that a sealing a rigid container with calcium carbide and water can produce acetylene under enough pressure to explode without a spark. Is that right?
When I was a kid, my Dad would either let us use his cigarette (to light fire crackers, etc.) but he taught us how to use a "punk," which was just a piece of ordinary cotton clothesline-type rope.
I heard that all you need to do is adjust your OA torch for a "neutral" flame, snuff it out in a sandbox or maybe against the bench, and capture whatever mix you've got. :-)
The strips need to be the correct length for the radar you are spoofing for a little bit of aluminum to have a decent sized signature.
Wavelengths for various kinds of radar can range from 100 meters down to
1 mm.
Air traffic control long range radar runs about 15 to 30 cm.
Local traffic control, weather and marine radar runs 7.5 to 15 cm.
Then there is "Speed Gating", the filters that knock off anything below a certain speed, so that every pigeon and seagull doesn't show up on the screen..
OK, a corner reflector. But I am intrigued by that velocity thing - would the blip get suppressed? If so it sounds like a perfect window for dropping something nasty, by just flying it in on a small blimp.
your correct, you get a nice blue" neutral" flame mix [ thats usually a good indicator of perfect ratio], snuff it on a wet rag, not a sand box!!! you'll clog the tip. fill your bag, then re-light the flame and touch off the bag. I do this with Tim Horton/starbucks cups placed upside down with the edge overhanging a table about an inch. Even a small foam coffee cup sounds like a shotgun.
we just did a large garbage bag last weekend hung from a wire about six feet up and touched it off with a E-match and 100' of wire . sounds like a howitzer!!!!
"Probably" . I do know that acetylene becomes unstable above (IIRC) 15psi unless it's dissolved in a solvent (acetone ?) . I think it would depend on how much cc and what size container .
When a substance detonates, energy from the surface of the detonating part is transferred into the not-yet-detonated part of the substance, and causes that part to detonate, and so on - this is how the detonation progresses. This surface usually has a radius.
As an instance, if you start from a point in an infinitely large block of substance then the detonation wave takes the form of an ever expanding sphere.
Now consider a tiny bit of not-yet-detonated substance which is just about to get hit by a detonation wave.
If the wave is tightly curved then the bit is getting energy from the points on the wave which are closest to it in an efficient manner, but the parts of the wave nearby are further away from the bit than they would be if the wave was flat -- the energy transferred to such an bit from a tightly curved wave is less than (and is transferred slower than) the energy transferred by a flat wave.
If the total energy transferred is not enough, or the energy is not transferred fast enough, the bit won't detonate, and the wave will die out.
This process means that in order to propagate a detonation wave has to have at least a certain minimum radius.
In PETN, used in detcord, the minimum radius is very small, less than a millimeter. In more usual high explosives it's on the order of a couple of millimeters. In gunpowder it's about a foot (yes, gunpowder will detonate if there is enough of it).
Probably. It's not something I'd care to try, and it's probably illegal too.
For acetylene at 15 psia the minimum radius of detonation is about a couple of inches - the exact figure is subject to dispute.
This means that it's reasonably safe to use acetylene at 15 psia if the tubes it's in are less than a couple of inches across - even if a detonation starts (for instance in an acetylene/oxygen mix rather than in pure acetylene) it will die out in acetylene at 15 psia if the container is small.
At higher pressures the minimum detonation radius decreases, and a cylinder of high pressure acetylene would be extremely dangerous, so acetylene cylinders are filled with diatomaceous earth [1] mixed with cement, or similar substances, to fill up the spaces.
The acetylene is also dissolved in acetone, so the pressure in the cylinder is less for a specific amount of acetylene.
[1] as used in dynamite to lessen the sensitivity of nitroglycerin - same principle, lowering the maximum radius of the substance available so it's less than the minimum detonation radius
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