Ionforbes Posted October 27, 2020 Share Posted October 27, 2020 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! Link to comment Share on other sites More sharing options...
Piccaso Posted October 28, 2020 Share Posted October 28, 2020 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. 1 Link to comment Share on other sites More sharing options...
Carbon796 Posted October 28, 2020 Share Posted October 28, 2020 Did you balance out the fuel value of the epoxy. With the available oxygen supplied by the nitrate ? Link to comment Share on other sites More sharing options...
BetICouldMake1 Posted October 28, 2020 Share Posted October 28, 2020 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. Link to comment Share on other sites More sharing options...
Ionforbes Posted October 28, 2020 Author Share Posted October 28, 2020 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? Link to comment Share on other sites More sharing options...
rogeryermaw Posted October 28, 2020 Share Posted October 28, 2020 (edited) 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 October 28, 2020 by rogeryermaw Link to comment Share on other sites More sharing options...
Piccaso Posted October 30, 2020 Share Posted October 30, 2020 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. Link to comment Share on other sites More sharing options...
SkyArt Posted November 2, 2020 Share Posted November 2, 2020 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-rocketry.net/rnx_int.html Link to comment Share on other sites More sharing options...
Ionforbes Posted November 2, 2020 Author Share Posted November 2, 2020 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? Link to comment Share on other sites More sharing options...
SkyArt Posted November 2, 2020 Share Posted November 2, 2020 (edited) 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 November 2, 2020 by SkyArt Link to comment Share on other sites More sharing options...
SkyArt Posted November 2, 2020 Share Posted November 2, 2020 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.amateurpyro.com/forums/topic/2217-kclo4epoxy-resin-propellant/ Link to comment Share on other sites More sharing options...
Androbroiler Posted May 3, 2021 Share Posted May 3, 2021 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. Link to comment Share on other sites More sharing options...
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