Nessalco Posted September 4, 2012 Posted September 4, 2012 I think I've finally gotten how to make proper blackmatch. Yeah, I know, a simple skill - but I want a reliable product, with reproducible effects, but that had eluded me so far. For the most part the blackmatch will go into pipe for quickmatch. Until recently I had used the "keelhaul" method of making match - dragging the string through a BP slurry. I was really not happy with the result - too easy to leave white spots, there was a solid white core, and powder would flake and crack off. I discovered that dissolving the dextrin in hot water before adding to the powder helped, but did not solve the problem. At best I had what I would describe as 'inconsistent' results - enough so that I chose to use fast fuse in pipe in lieu of real quickmatch this year for my show. (Note to self: Don't do that again. That perchlorate based stuff overpressurizes and goes bang far too easily...) I had seen the method of making a hank of string, then soaking it in the BP slurry, and gave that a try. For all of these attempts I used 200g of home made willow BP powder to treat 250' of 6-ply cotton string. The string was soaked in the BP slurry until it had all been absorbed. It is then drawn through an aluminum sizing die onto a loom. In my first attempt I used 5% dextrin, but got the mix a bit too watery. I also made the mistake of using very hot water (180F+) to dissolve the BP granules. The result was a good black core, but there were visible crystals at the surface, and the burn was quite slaggy. I suspect between too much water and too much heat, the KNO3 was redissolved. Even so, the match burned consistently, and was reasonable fast in a pipe though not at all aggressive. The nice thing was there was no flaking off of powder at all. The match can be bent sharply (and will 'break' at the bend) but it does not seem to affect the burn rate at all. It lights easily from an ematch. In my second attempt I used 4% dextrin in warm water, with 1% CMC. I got this slurry *way* too watery, not fully recognizing the effect of the CMC. It took forever to dry, and there was still some redeposition of KNO3. Still, it was a significant improvement over the first batch. It works well enough that I pulled it into quickmatch. In my most recent (and I think finally correct) batch, I used 4% dextrin and 1% CMC, and just enough water to dissolve the BP granules. The resulting mix was more the consistency of wheat paste than a slurry. I threw in the string and worked the BP in the best I could. I actually got the mix a bit too dry, and had to use a spray bottle to add water a bit at a time until the string picked up all of the powder and there was no white visible anywhere within the hank. Then I pummeled it for a few minutes more to make sure the powder was fully worked in. I wound this on the loom and it was dry within a few hours - compared to a few days for previous batches. The result is excellent. I see no sign of crystals on the surface of the match. Burns consistently, very little slag, and lights perfectly from an ematch. No white core at all. Performs beautifully and predictably in quickmatch. I'm using three strands in flat match, with pipe that puffs out to about 5/16". Lightning fast, easy to work with, and it goes "whoosh" rather than "bang!!" Just what I was hoping for. I'm finding I like pyro more and more. The time and effort required to get the basic skills right is significant, and significantly rewarding. Kevin 1
psyco_1322 Posted September 4, 2012 Posted September 4, 2012 Something you might try is soaking your string in water before putting it into the slurry. It helps to not dry up the slurry since the string isn't trying to soak up water. Some people use a nitrate solution, but I see it as unnecessary and altering the ratios of your powder.
Mumbles Posted September 4, 2012 Posted September 4, 2012 The water the string soaks up is not just water. It's water plus whatever nitrate it has already dissolved. This is the rationale behind using nitrate solution to pre-wet the string. I've found that it's not too big of a deal as long as you can use up most of the slurry. The kneeding helps to keep everything homogeneous throughout. It sounds like you got your ratios about right. I found that 1g per foot is about right, but there is some left over. The next time I make any, I'll give your ratio a shot. Now that I think of it I do usually end up using an extra 50 feet or so to sort of soak up the extra paste. What kind of string did you end up using for the match?
Nessalco Posted September 5, 2012 Author Posted September 5, 2012 What kind of string did you end up using for the match? It's 6-ply cotton that I inherited when we cleaned out my mom's house. It is on a cone, and the whole thing weighs a bit over 5 pounds. I've used over 1000' already and it hasn't even made a dent. I guess I have string for life... Kevin
Dvorhagen Posted September 25, 2012 Posted September 25, 2012 Hi, all! I'm new to the forum, and to amateur pyrotechnics in general. I've found, over my many years of casual pyro experimentation, that making good fuse/initiator is one of the trickiest things about this hobby. I've tried several variations on black match (brown match with KNO3/sucrose, paper fuse, black match with various binders) and none seems to work well. Does anyone have a good suggestion for a quick and dirty fuse solution for testing compositions -- something like touch paper, but more evenly burning and able to stay lit when confined?-D 1
dagabu Posted September 25, 2012 Posted September 25, 2012 Try: PEACHES & CREME CONES 14 OZ WHITE IMHO, it is the best yarn to make black match from, it absorbs the slurry like mad and is 100% cotton. -dag
dagabu Posted September 25, 2012 Posted September 25, 2012 Hi, all! I'm new to the forum, and to amateur pyrotechnics in general. I've found, over my many years of casual pyro experimentation, that making good fuse/initiator is one of the trickiest things about this hobby. I've tried several variations on black match (brown match with KNO3/sucrose, paper fuse, black match with various binders) and none seems to work well. Does anyone have a good suggestion for a quick and dirty fuse solution for testing compositions -- something like touch paper, but more evenly burning and able to stay lit when confined?-D I tape a 3" piece of visco to a board and punch a hole through the bottom of a 1 oz paper cup, lead the visco through the hole and place my sample in the cup. There is virtually no danger of a premature ignition this way. -dag 1
Dvorhagen Posted September 25, 2012 Posted September 25, 2012 Thanks for the reply - yeah, I wonder if I just haven't found a good yarn/string. Maybe what I've been using isn't absorbent enough. I would just give up and buy visco or something, but I live in MA and they're very restrictive about such things here. Ever try making paper fuse with green mix or something? It seems like it should work, but I haven't had much luck..
dagabu Posted September 25, 2012 Posted September 25, 2012 Thanks for the reply - yeah, I wonder if I just haven't found a good yarn/string. Maybe what I've been using isn't absorbent enough. I would just give up and buy visco or something, but I live in MA and they're very restrictive about such things here. Ever try making paper fuse with green mix or something? It seems like it should work, but I haven't had much luck.. Black match is so darn easy to make and so reliable that I would never even try paper match of any kind. You have to ball mill your 75:15:10 to get a good burn then add 5% dextrin and hot water, 1% CMC works to keep the comp in suspension and if you make a hank of yarn, tie it off and knead the hank in the slurry, run it to a drying frame, you should have fine BM. -dag
Mumbles Posted September 25, 2012 Posted September 25, 2012 You can certainly get visco shipped to MA if you wanted to. One of the older members here runs or used to run a business which sold visco out of MA actually. http://www.buyviscofuse.com/index.html This is actually becoming a favorite thread of mine. I really like seeing the progression of getting to great match, and I've recommended and linked it to several people. One trick I've found for getting the consistency just right is to give the container containing the slurry a knock to start a wave. You want the wave to get to the other side of the container, but not make it all the way back. This is with warm water. It's just much nicer on the hands too. I would generally start with pretty warm water, but it cools down quickly in contact with the BP as the KNO3 dissolves.
dagabu Posted September 25, 2012 Posted September 25, 2012 I just use boiling water for the mix, it cools to "warm" in about 5 minutes. By that time I already have the string soaked and ready to pull. -dag
viziers Posted September 27, 2012 Posted September 27, 2012 I recently made a couple batches of match and I used warm water and kneeded the string in the BP and let it soak there until I had all my cut lenghs to of 28" soaking then i pull it through a silicone nozzle (the ones that screw on to the tube) hang it for 4 to 5 days... So far it seems to work pretty good burning unconfined, but I have noticed that when I put 2 lengths in my rolled leader pipes it burns something fierce and has blown out the side of the leader pipe but still keeps traveling to the end... I have also bent the match multiple times to see if it causes a delay when burnt unconfined/confined and I did not notice any delays.. I also cut one match in various places and I noticed the BP did not soak completely through to the core but close to it.... We will see how it does this Saturday when I launch 2 4" canisters (fingers crossed they break correctly and not like a opening can of pop) http://media.recordsetter.com/R81_lg.jpg vizi
dagabu Posted September 27, 2012 Posted September 27, 2012 So far it seems to work pretty good burning unconfined, but I have noticed that when I put 2 lengths in my rolled leader pipes it burns something fierce and has blown out the side of the leader pipe but still keeps traveling to the end... I have also bent the match multiple times to see if it causes a delay when burnt unconfined/confined and I did not notice any delays.. I also cut one match in various places and I noticed the BP did not soak completely through to the core but close to it.... vizi That is EXACTLY what black match should do inside a pipe and blowing out the side of the leader is a good thing as the excess gas created can escape the containment through the pipe wall. Good job! -dag
Mumbles Posted September 27, 2012 Posted September 27, 2012 It sound like you have good match there Vizi. With a lot of kneeding, I can usually get BP slurry all the way through the string core, however when you can still see the individual white strings usually. As long as it's decently penetrated, you'll be fine for any application. Good luck with the shells.
dan999ification Posted September 27, 2012 Posted September 27, 2012 the serious business of pyrotechnics, if twisted ply cotton string is used not only will it be absorbant but you can un twist the ply before you kneed and pull it, someone here used a drill to un twist it and re twist it after pulling, solves the white core problem but it has never bothered me, the match burns steady.If the match blows the pipe but keeps going it is good match, my bought qm makes the same effect ( pull one strand out tie both ends and you have a bp firecracker)said it before, for the fastest match dust it in meal d, it will speed up significantly but will blow thinner pipes easy ( still carrying on its way ). Dan.
Mumbles Posted September 27, 2012 Posted September 27, 2012 There really is no good reason to untwist string, and then retwist it. It's going to be bound together by the BP, so the retwisting is doing nothing besides squeezing BP out of the product. It'd make much more sense, and be significantly less work, to run several strands of string together and size them into the final product. This is really the only way to make the systems that pull string through a slurry yield good match. The people who try to pull a single twisted yarn through a slurry to give a single stick of match are wasting their time and materials.
dan999ification Posted September 27, 2012 Posted September 27, 2012 i use 3 or 5 strands and dont twist or untwist, the match is good but'not as good as commercial 5 strand.I see what you are saying, i never tried it thank god my match is alright. Dan.
dagabu Posted September 28, 2012 Posted September 28, 2012 There really is no good reason to untwist string, and then retwist it. It's going to be bound together by the BP, so the retwisting is doing nothing besides squeezing BP out of the product. It'd make much more sense, and be significantly less work, to run several strands of string together and size them into the final product. This is really the only way to make the systems that pull string through a slurry yield good match. The people who try to pull a single twisted yarn through a slurry to give a single stick of match are wasting their time and materials. Not in my experience Mum. I have been using only worsted yarn (Peaches and Cream 100% cotton) and find complete penetration when hanked and kneaded. I certainly agree with there being no need to unwind it and I see no reason to have seprate strands run through a die either. The one exception is the 5 string flat match I use for timed reports, that is run through a flat die, 1/32" thick. -dag
Col Posted October 27, 2012 Posted October 27, 2012 (edited) the serious business of pyrotechnics, if twisted ply cotton string is used not only will it be absorbant but you can un twist the ply before you kneed and pull it, someone here used a drill to un twist it and re twist it after pulling, solves the white core problem but it has never bothered me, the match burns steady.If the match blows the pipe but keeps going it is good match, my bought qm makes the same effect ( pull one strand out tie both ends and you have a bp firecracker)said it before, for the fastest match dust it in meal d, it will speed up significantly but will blow thinner pipes easy ( still carrying on its way ). Dan. I use a power drill to untwist 9 ply cotton string to make chunky blackmatch to ignite rocket cores. I find the slurry penetrates the strands better and it dries fairly quick too (overnight in the drying box and its ready to go). I use milled bp 75/15/10 (willow), +4% dex, +1% cmc.I dont retwist it afterwards Edited October 27, 2012 by Col
Sinken Posted May 22, 2013 Posted May 22, 2013 I guess it's this one. http://web.archive.org/web/20101221184632/http://pyroguide.com/index.php?title=CMC
Mumbles Posted May 22, 2013 Posted May 22, 2013 Not all wallpaper paste is made from CMC so that's not a particularly good suggestion.
pyrojig Posted May 23, 2013 Posted May 23, 2013 I use just plain 'ol' dextrin 5% to do the dirty work, and have never had bad match. Much goes into the initial prep and mashing of the slurry into the string.This is done before pulling it through the die , and to the rack to dry.I too enjoy seeing the diff methods used to obtain good hot match. Another fellow swears by using starch as a binder, he gets pliable and smok'n hot match.
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