Hockeydemon
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Relatively safe impact smoke grenade ideas?
Seeing as the other thread on impact deflagration devices was closed for getting off topic, and being unsafe. I would like to get that conversation
back on topic because I think we could come up with a relatively safe way to make a 'smoke grenade'.
After searching around I found someone who made a pretty decent 'torinoko' on youtube by utilizing the caps from a cap-gun wedged between two rocks
surrounded by flash powder from firecrackers, and wrapped in toilet paper.
Now Armstrong's mixture kind of scares me, but I really don't want to sit and take out hundreds of little caps either. I feel that there must be a
reasonable way to make small quantities of Armstrong's mixture at separate times from matches, and some oxidizer (suggestions?). In my mind I would
like 1x1" paper squares - though I truthfully cannot speak to the dangers of this so your wisdom or suggestions would be appreciated.
Next comes the task of smoke production. After looking at what the military uses I quickly decided I am not overly interested in
hexachloroethane/zinc, terephthalic acid, or WP mixtures. These are all unreasonably toxic for a fun toy IMO. After searching around I found a neat
(free) publication from a laboratory who went about trying to find a replacement smoke grenade coming from a safety aspect (I believe for military
training purposes). Here is the link to the .pdf containing the publication - I'm sure some of you will find something interesting in it.
Here is the abstract:
| Quote: |
The compositions made were containing various amounts of NaClO3, cellulose, CaCO3 and Mg (from two different sources). From the laboratory scaled
tests the composition named “11EM0745” was the best performing composition made. When these compositions are compared to the benchmark obscurant
compositions (HC smoke, red phosphorus smoke, and TPA smoke) it is concluded that the transmissions through the smoke of the new sea-salt compositions
are much higher compared to the HC and RP smoke, but lower compared to the TPA smoke. The smoke from developed compositions are less toxic than the
HC, RP and TPA smokes.
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I think their composition (ratio's provided) is reasonably safe for a fun toy. However I can't say I know whether or not it is feasible to use an
impact ignition source such as Armstrong's mixture in order to light it. I'm open to suggestions here also.
Last but not least comes the containment vessel. I guess this would depend on what is required for an ignition source, but continuing with
Armstrong's mixture until I'm given a better idea.. I was thinking eggs? I'm not exactly sure how to make a straight cut around an egg, but it has to
be possible. Eggs are incredibly cheap - you could cut them in half, remove the contents, place a piece of that 1x1" Amstrong's paper in the egg with
some sort of abrasive material upon it. Then fill the egg with the smoke mixture mentioned before hand - then simply use super-glue to close the egg
back up (or tape idk).
Hopefully this sparked some sort of ideas on how to go about this. It needs to be relatively safe to use, and I would like that it not leave behind
something potentially hazardous such as glass shards, chemicals ect..
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Bot0nist
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Remember, these pose a serious fire hazard. starage is a no no, and whenever, whoever is handling them they must be ready for it to light at anytime.
A small amount of Armstrongs mix can be had from matchbooks and KClO3 from the bleach. just wash the impure phosphorus with plenty of atone to remove
most of the adhesive. And for gods sake, ever mix more than a couple 100mg. It is sooo easy to destroy your fingers and eyes with even little bits of
armstrong mix. I doubt it is the best choice for your project anyways.
Maybe a couple R candy ball with a small patch or spot of KClO3/sugar and think up some way for a tiny amount of H2SO4 to come into contact with it,
when ignition is needed.
IDK though, its not an easy problem without some good engineering.
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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Hockeydemon
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What is it that makes the little papers from cap guns 'less reactive'? I get that they are obviously small, and contain a minimal amount of Amstrong's
mixture, but I remember playing with the little papers from the caps when I was younger. How would I go about calculating the catalytic amount of the
mixture I'd need in order to ignite the mixture composition described in the publication?
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chemcam
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I don't think your ignition source is going to work very well, two scenarios for you, you fill the egg with powder because that has the best
properties for ignition. You throw the egg, hits the ground, powder cushions the blow and nothing happens other than your mixture is now around
outside the broken egg shell. Scenario 2, you throw the egg it hits the grounds, this time the charge goes off but the explosion spreads the smoke
powder out so thin it burns within 2 seconds, more like smoke blanket.
I think this topic is more about engineering, and not possible by a home chemist, at least a safe one is not possible. If you use a metal container
you cant have the charge in the middle or it will explode without a proper vent hole anyway.
If I were forced to make an impact smoke grenade in an egg shell I would forget about explosives and just do the process in an inert atmosphere, and I
would add a certain amount of pyrophoric metal into the smoke mix and make sure the seal is air tight.  That is a lot easier than it sounds trust me, I use argon atmospheres all the time for welding aluminum and for
certain experiments.
This is a throw down bang-snap I made with SA*DS you could do something like this but use much less if you are stuck on igniting with explosive
material.
SA*DS Bang Snap 1 (from distance)
SA*DS Bang Snap 2 (close-up)
[Edited on 5-7-2013 by chemcam]
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Finnnicus
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Hey chemcam, on an semi-related note. How hard is it to get argon? Price? License?
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Bot0nist
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In the usa. Easy peezy. 18 or older and i think it is OTC...
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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chemcam
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Very easy to get it, no license needed, I forget the cost its been a while since I needed a refill, my tank is huge. For MIG welding you need inert
atmosphere so the weld doesn't oxidize. Some though are mixed gas cylinders which are argon and CO2. I have both kind along side oxygen and acetylene,
I had a nitrogen tank but I left it out front and it got stolen. 
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Finnnicus
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Back to the subject, I yet again recommend strike anywhere matchheads for the amateur. They work great, but I can't buy more here in Australia.
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Hockeydemon
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<HTML>
<Body>
Here is the composition I feel has the best chance of working, and the data they acquired while testing it. Any thoughts?
Why is this space here?!
<table border="1">
<td><td>Composition(wt%)</td>
<tr>
<td>NaClO3<td> 69%</td>
<tr>
<td>Cellulose<td> 23%</td>
<tr>
<td>Mg<td>3%</td>
<tr>
<td>Oxbal (%)<td> 2%</td>
<tr>
<td>Solids (%)<td>45%</td>
</tr>
<tr>
<td>Friction Sensitivity[N]<td>Relative Humidity %<td>[Temp C]</td>
<tr>
<td>120<td> 47.1%<td> 17.7C</td>
<tr>
<td>Impact Sensitivity[Nm]<td>Relative Humidity %<td>[Temp C]</td>
<tr>
<td>30<td>47<td>18.1</td>
</table>
</body>
</html>
[Edited on 8-5-2013 by Hockeydemon]
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APO
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I started a "Deflagration On Impact" thread, but it got away from me and it was closed since people started talking about 3kgs of APAN (which is
crazy), but in the mean time I thought maybe some magnesium/ferrocerium could be a start.
"Damn it George! I told you not to drop me!"
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Dornier 335A
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I have some experience with impact igniters.
My solution was to make a device that was ignited by strong acceleration in one direction only, rather than have something that ignites on contact
anywhere. This makes it much safer to handle and store.
Here is a small diagram:
The whole thing can be as small as a few cm long and 5 mm thick. The primary of choice is Armstrong's mixture with coarse magnesium powder. It
deflagrates relatively slowly with a hot flame.
To further increase safety, this can be stored separately and inserted into the smoke mix just before use.
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