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very snappy e-match


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#21 dave321

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Posted 15 February 2021 - 03:42 PM

That flame will be nowhere near as hot as a metal-enhanced mix, but might be sufficient for assisting BP motor ignition. Picasso was on the right track in his earlier post in this thread. If possible, use water-free acetone to minimize wire corrosion/oxidation over time if storing.

 

And "snappy" is not always a good thing, though it might sound kinda cool. Many of the pyrogen kits for model rocketry use a plastic plasticizer instead of NC, and some folks redip in plain NC lacquer after a pyrogen/NC dip, to provide "protection". Both will contain/confine your burn and cause pop, but that'll do very little to enhance ignition. Plastic coatings actually risk inhibiting flame transfer between pyrogen and target, and NC coatings though flammable, don't burn as fast as your pyrogen (thus containing it) except at very high (gun chamber) pressures (but at least it's flammable...). Find  what works. For hard-to-light items like AP rocket motors (for example) the heat of MgAl burning goes a long way.

 

this thread has nothing to do with trying to create an e-match for ignition purposes.

its all about creating a very snappy, LOUD bang "e-match" to produce noise or which could be used as a bullet hit effect in dry plaster board walls


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#22 SharkWhisperer

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Posted 15 February 2021 - 04:37 PM

 

this thread has nothing to do with trying to create an e-match for ignition purposes.

its all about creating a very snappy, LOUD bang "e-match" to produce noise or which could be used as a bullet hit effect in dry plaster board walls

Aha, I see. Well, I still think Picasso is on the right track. Dip in an NC slurry and cover with a final dip in pure NC lacquer or just a plasticizer for a containment coating. Any semi-hot to hot FP can be made to burst loudly in small volumes. So will a dark flash that doesn't produce a lot of light output. Easy to whip up a few grams of various suspects/experimentals for cheap and test 'em out. Use a decibal meter to get active readings.

 

Big difference if you're looking for particleboard shatter/separation or sound, because bullets don't typically make exploding sounds on impact. Tons of established FX squibs already available,with MSDS showing basic comps but not details of construction. You shouldn't have any real issue replicating them. I can imagine some more brissant components more similar to that used in firearm cartridge primers that in low quantities could be coated for "safety" and easily snap with an electrical charge application. Would need to see if there'd different shipping regs for different formats--i can just walk into any sporting goods store and buy boxes of primers (when they're not in short supply like they are now some places). Simple to extract and reformulate, though obviously that's not what a commercial vendor is doing.

 

Will be interesting to see what you arrive at.



#23 WRAITH

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Posted 18 February 2021 - 03:17 AM

I don't usually coat my ignitors as i never found corrosion on nickel/chrome because Nichrome wire develops an outer layer of chromium oxide, which makes the wire thermodynamically stable around oxygen. If i need it to ignite thermite or metal based pyrotechnics, i make a sparkler mix slurry & then coat it with nail polish. Different color nailpolish for different compositions so i know what to use them for.

#24 Mumbles

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Posted 18 February 2021 - 11:10 AM

Using non-aqueous binders usually helps with any corrosion.  Using non-nitrate based formulas, at least for the initial dip also generally helps.  I'm familiar with a manufacturer who was experimenting with alternative formulas and processes to try to improve cost and reduce some sensitivity issues.  Shelf life became an issue with some of the attempts within about 6 months if I recall. 

 

Visually, those matches look to be a single composition.  The potassium ferricyanide suggestion made is not a bad one.  The red color would be consistent.  Another distinct possibility would be a composition containing elemental boron.  Finely powdered boron is remarkably reactive.  I've seen some mentions that their Firewire igniters are based on "other thermite formulations".  Something of this nature was brought up as a possibility https://arc.aiaa.org/doi/pdf/10.2514/1.24915 

 

Another thing I've been thinking of is an overcoat of something.  Basically some sort of minor confinement to increase the noise level.  I've seen some testers of e-match made with H3 and the same thing coated with BP by Octavio Aguiar.  The BP coated ones threw off considerably more flame and seemed louder.  He reported that they were allegedly safer due to the lack of exposed chlorate as well.  It's been probably a decade, but I wouldn't say they were as loud as the FER initiators. 


Just so you guys quit asking, here is the link to the old forum. http://www.xsorbit2....forum/index.cgi

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#25 dave321

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Posted 18 February 2021 - 02:07 PM

 Something of this nature was brought up as a possibility https://arc.aiaa.org/doi/pdf/10.2514/1.24915 

 

 mumbles,

 

pm sent

also the above link does not seem to work


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#26 WRAITH

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Posted 19 February 2021 - 07:52 AM

Sounds real snappy like when you add a drop of concentrated sulfuric acid on to potassium permanganate, then when it changes color from purple to clear it starts releasing ozone & all you do to make it explode is add 1 drop of alcohol to it & detonation occurs.
It could even be a mix like Crimson Powder with the chemistry of Potassium Nitrate, Ascorbic acid & Red iron oxide.

#27 WRAITH

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Posted 20 February 2021 - 06:54 AM

Mercury fulminate & potassium chlorate snaps that way. Potassium ferricyanide is not flammable or explosive on it's own unless it's mixed with nitrite salts & could possibly explode if mixed with a solution of concentrated ammonia.

#28 Mumbles

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Posted 20 February 2021 - 11:26 AM

http://arc.aiaa.org/...10.2514/1.24915
 
Sorry, the forum is weird about putting spaces at the end of links sometimes, which gets included in the URL.


Just so you guys quit asking, here is the link to the old forum. http://www.xsorbit2....forum/index.cgi

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#29 SharkWhisperer

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Posted 23 February 2021 - 11:34 PM

http://arc.aiaa.org/...10.2514/1.24915
 
Sorry, the forum is weird about putting spaces at the end of links sometimes, which gets included in the URL.

You might find a slideshow summary of this groups' practical conclusions interesting. And neither copyrighted nor behind a paywall: https://ndiastorage....kiewTuesday.pdf



#30 dave321

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Posted 26 February 2021 - 12:33 PM

re the posted video

 

 

that is one loud , snappy bang, more of a crack

 

personally, i do not think it sounds like it is due to "confinement" by coating the fusehead with a rigid coating, since it is more of

a loud "crack".

 

i simply do not know any composition that comes anywhere near this effect, although a dragons egg composition could be similar, 

but there is no lag time from the fusehead unlike a dragons egg composition.

 

maybe a nano thermite type composition would give this effect ? 


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#31 WRAITH

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Posted 28 February 2021 - 10:38 PM

Could be that nano explosive, but an ever long process to create.
Sounds even more like an explosion of silver carbide (silver acetylide), Ag²C².
Google it & guys, how do you add video to this ?
Thanks

#32 dave321

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Posted 01 March 2021 - 02:09 PM

no its not SADS, there is too much smoke,

also although sads makes a nice bang, it is a relatively weak explosive, also 

the manufacturer states no lead, no primary.

 

i do think it contains copper oxide since there is a black residue after firing


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