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Epoxy-Oxidiser fuse


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#1 Ionforbes

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Posted 27 October 2020 - 05:33 PM

So I tried making fuse using epoxy and string where I mix finely powdered KNO3 with epoxy resin into a slurry, and apply it to string in a similar way as blackmatch. However it only burns reluctantly so I guess I'll need potassium chlorate. I know chlorate based flash powders tend to explode if you store them too long, does the same apply for all chlorate mixtures? I live in a very rainy area so blackmatch is kind of pain to use so I need something water resistant like epoxy, but if it self-ignites after a week then obviously it's not worth it. Any info much appreciated!

 



#2 Piccaso

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Posted 27 October 2020 - 06:39 PM

Chlorates are generally prone to self ignition when mixed with things they shouldn't be like sulfur for instance. They also react strongly with organics. I am by no means an expert in them as I use them very little and then only in proven formulas. Be very careful mixing chlorates with organic substances without first researching what they will do. Chlorates mixed with certain things make explosives that are very sensitive. I do not have the answer you are looking for but you are barking up a dangerous tree.


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#3 Carbon796

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Posted 27 October 2020 - 10:57 PM

Did you balance out the fuel value of the epoxy. With the available oxygen supplied by the nitrate ?

#4 BetICouldMake1

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Posted 28 October 2020 - 08:05 AM

Have you considered applying a coating to your black match rather than mixing it into the slurry? Thin epoxy may work or something like pvc cement.

#5 Ionforbes

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Posted 28 October 2020 - 08:38 AM

What sort of coating would you consider? Nitrocellulose lacqeur isn't available where I live (maybe it is but I don't know what it would be called). Could a coating also act as confinement and tuen it into quickmatch?

#6 rogeryermaw

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Posted 28 October 2020 - 01:10 PM

it's not really confinement that turns black match into quick match. the sleeve provides a channel for sparks to fly forward and quickly ignite match downstream.

 

eh...i guess in some sense it is confinement but if you wrap black match tightly, it's not that fast.


Edited by rogeryermaw, 28 October 2020 - 01:11 PM.


#7 Piccaso

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Posted 30 October 2020 - 05:31 PM

You could try applying your epoxy to a string to get it sticky and then roll or dredge the string through a nitrate based slow flash mixture before it hardens. Regular cheap glue would do the same just dry slower. I do not know if it will work just a guess.



#8 SkyArt

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Posted 02 November 2020 - 01:04 PM

Try adding a small amount of iron oxide? I have no experience with this but i am always on the quest for better/more durable black match.
This link is where i got the idea, they say without iron oxide it burnt way to slow.
http://www.nakka-roc...et/rnx_int.html

#9 Ionforbes

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Posted 02 November 2020 - 02:31 PM

I'll give it a go with iron oxide and update. I think this a great candidate for a fuse since epoxy is strong, flexible (when drawn out thin) and waterproof. Does it matter if I use Fe(II)O or Fe(III)2O3? Could I just use regular rust?



#10 SkyArt

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Posted 02 November 2020 - 03:03 PM

I am not sure, I would try experimenting with different catalysts. Maybe someone with more experience would have better insight.
"In addition to epoxy and potassium nitrate, a third constituent makes up the RNX propellants -- Ferric Oxide (Fe2O3). Also known as iron oxide (common rust), this is the key ingredient that led to the successful development of the RNX propellant. Without Ferric Oxide, the formulation simply burns too slowly to produce a practical propellant. Small quantities of Ferric Oxide will increase the burn rate significantly, but the resulting formulation possesses a burn rate pressure exponent (symbolized as "n") that is too high to produce a successful propellant. After much development work, it was found that a relatively large percentage (8%) of Ferric Oxide provides the requisite traits -- moderate burn rate and reduced pressure exponent."
- Richard Nakka

Edited by SkyArt, 02 November 2020 - 03:47 PM.


#11 SkyArt

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Posted 02 November 2020 - 03:24 PM

This discussion also has some good stuff. I know its all for rockets but I think it will somewhat translate to fuse or at least be helpful. I may be making fuse later this week!

https://www.amateurp...sin-propellant/

#12 Androbroiler

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Posted 03 May 2021 - 06:44 AM

I read somewhere in russian literature about so-called "white match" which is made like "black match" but instead of BP composition of phenolic resin + potassium nitrate is used.

 

I used the following composition:

 

Phenolic resin - 30%

Potassium nitrate - 70%

solvent - ethanol

 

 

The burning rate of such fuse is about a half of black match and it is more resistent to humidity and moisture.






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