braddsn Posted September 29, 2014 Posted September 29, 2014 I know when installing the time fuse in a ball shell, it is standard to split and crossmatch the bottom of the time fuse (inside the lift cup). I am just thinking out loud but, would it not be just as effective to maybe dip that end of the time fuse into some fencepost prime and call it good? I understand that crossmatching is to ensure fire transfer, but when making many shells, I would think this would be time consuming as opposed to just dipping in prime. We rely on prime to light other things, so why not rely on it to ensure fire transfer to the time fuse? BTW I am not being lazy... just wondering if the crossmatching may be overkill. I guess if nothing else, I can experiment a little. Thoughts?? Anyone else do it without crossmatching time fuse?
taiwanluthiers Posted September 29, 2014 Posted September 29, 2014 I tried that, and had a bunch of duds as a result. Crossmatching works every time. You don't even have to tie it, you can simply cut a split and jam the black match into the split if you have too little space.
braddsn Posted September 29, 2014 Author Posted September 29, 2014 In Takeo Shimizu (Firework art, science, and Technique) he shows several examples of ways to prepare fuse.. it kind of leads me to believe that experimentation might be the key. I particularly like the example where he cuts one end of the fuse at an angle. I would think that if you cut the fuse at an angle like that and primed it, it would take fire.
schroedinger Posted September 29, 2014 Posted September 29, 2014 It can work, many chinese shells are fired like this, most times incorparating two time fuses, other crossmatch their shells. Like said before it is just done to ensure the lighning, but why do you wan't to spare it out? The cheapest tool for doing this can be gotten for about 3-5 $ (revelt style lether punch) and with these crossmatching takes about 2 seconds. Even faster and more precise with some of the professional tooling available. Also you can look into priming by tying blackmatch onto the timefuse, have a look at vikings bomba da tiro construction videos to see how he did it.
dagabu Posted September 29, 2014 Posted September 29, 2014 I think that this is a common question when people start out building, once the experience of dropping a shell that has several hours of work into it is yours, i expect you will be very critical of your methods and start to cross match. I for one do not like to split the time fuse, I have had shells do a round trip that I spent all weekend preparing just because of the weaknesses of this kind of fusing. i prefer punching the time fuse and running two strands of good QM. For cylinders its allways spollettes with a drilled back core for timing nosed with several strands of QM.
enanthate Posted October 11, 2014 Posted October 11, 2014 I've shot around 30 shells, never crossmatched or primed the timefuse, never had a failure. Take a knife and just scrape the surface at the end of the fuse just before attaching the liftcup, leaving the fuse's surface fresh and rough. Ignites everytime.
Mumbles Posted October 11, 2014 Posted October 11, 2014 I wouldn't really consider 30 shells to be a large sample size. I have no doubts that it normally works fine, but this is more about avoiding that perfect storm of scenarios. Even 1% failure is too much for me. It's really a belt and suspenders approach. I'd rather take the extra 30 seconds and crossmatch or otherwise prime the fuse and only really need it 1 out of 100 or even 500 shells than risk dropping a shell I spent hours on or risk damaging property or individuals.
enanthate Posted October 11, 2014 Posted October 11, 2014 True, Mumbles.However, crossmatching would take me some extra time, and in say 100 shells, that time is probably more than losing a shell. At least in my case anyway, since I need to make the fuse and with no experience that also takes time. I need to experience the disappointment before I comment on it I guess :>
MrB Posted October 11, 2014 Posted October 11, 2014 Time isn't the thing here. A unlit shell will make a roundtrip. Not only can it cause significant injury / damage when it impacts something, it may very well end up in someone-elses care, who has no idea what it is, and ends up getting hurt, or even killed.B!
nater Posted October 11, 2014 Posted October 11, 2014 So what so you do if you drop a shell? They can be tricky to find at night, if your time is so precious to you, why not take steps to prevent the need to search for a live shell?
enanthate Posted October 11, 2014 Posted October 11, 2014 (edited) Nater! You seem provoked....I don't disagree with any of you. I simply believe that scraping the timefuse might be good enough for ignition, so I threw it out there. If you disagree just say so.Have you tried it though? I wouldn't lose a shell, otherwise I wouldn't take the risk. Common sense, if you dont mind me saying. Edited October 11, 2014 by enanthate
MrB Posted October 11, 2014 Posted October 11, 2014 (edited) I've lost a couple. 3 different shoots, 4 shells. Didn't even bother to go looking for them.There is a reason i shoot over water. And it's not only the way it reflects on the surface. I can hear them land. And (early) the next day i can go look for them on the shores, if they drifted up there. Had different luck with that, but as it turns out... not all shells will float. Imagine that. I've come to decide that if they don't float, then they most likely wont be recovered by someone who's going to manage to set them off and get hurt. I've been using spolettes, primed and matched. Switching to proper time-fuse when i find / figure out how to make a proper punch for cross-matching, and can restock on stranded quick-match.B! Edited October 11, 2014 by MrB
ddewees Posted October 11, 2014 Posted October 11, 2014 It is easy to make a simple time fuse punch, and almost guarantees ignition. Worth the peace of mind.
dagabu Posted October 12, 2014 Posted October 12, 2014 Nater! You seem provoked....I don't disagree with any of you. I simply believe that scraping the timefuse might be good enough for ignition, so I threw it out there. If you disagree just say so.Have you tried it though? I wouldn't lose a shell, otherwise I wouldn't take the risk. Common sense, if you dont mind me saying. You are lucky and have fortune shining on you my friend. I made two shells with hundreds of timed inserts in them, I even cut the time fuse at a 60° to promote the fire. Many of them blew blind. It was a mess beyond compare and still haunts me. Of EVERY shell with timed inserts since then (100+), every insert has lit when properly primed, every shell I have lifted that was crossmatched has broke. I believe that its' a fools journey to think that this is an acceptable method, you will find no one to back you up in the gallery of the old snorts.
nater Posted October 12, 2014 Posted October 12, 2014 Building fireworks takes time and the vast majority of the people on these forums do it as a hobby. The time it takes to cross match a fuse on a shell is minimal, yet it greatly increases ignition. One master does not crossmatch time fuse, but does prime the ends with a BP slurry for precise timing. Nobody will argue with his results. Why cut corners and take the risk? Are you so rushed that a minute is too much time to prep your fuses? Nobody wants to spend the time on a shell and watch it make a round trip. When this happens, it MUST be retrieved.
ddewees Posted October 12, 2014 Posted October 12, 2014 I'm always amazed when Viking says he doesn't prime or crossmatch any of his timefuse... his results speak for themselves, and I've questioned the extra work since he doesn't seem to see the need. I'm talking about inserts, where it does take time and space. Ball shells is really not much extra work...
taiwanluthiers Posted October 12, 2014 Posted October 12, 2014 If a 3" shell makes a round trip, it may be difficult to find, and I really hope some kid don't find it because they might think it's some cool firecracker or something. If a 6" shell makes a round trip, it may cause property damage, it's practically a cannon ball. You want 100% ignition, even 1% failure is too much. I'm telling you that cutting a time fuse at an angle isn't enough. I have a dud to prove that. I took all the shells I made and went back and cross matched it and all of them lit.
enanthate Posted October 12, 2014 Posted October 12, 2014 If a 3" shell makes a round trip, it may be difficult to find, and I really hope some kid don't find it because they might think it's some cool firecracker or something. If a 6" shell makes a round trip, it may cause property damage, it's practically a cannon ball.Sounds like you need a better location.Dont fire in a neighbourhood, etc.
nater Posted October 12, 2014 Posted October 12, 2014 We lost a shoot site because of the crater a shell made in a farmer's corn field. You don't want someone cutting hay or beans to find a live shell any more than you want a kid or pet to find one. We have lost shoot sites because of non-explosive debris left behind as well. Part of shooting fireworks is cleaning up after yourself. Be a good guest to someone gracious enough to host you. If you shoot on your own land, be a good steward to the hobby and leave as little behind as possible. I have shot fireworks on golf courses, athletic fields, public beaches, parks, cattle fields, parking lots, amusement parks, etc... In all of those places, and any others you shoot fireworks it is important to clean up your mess. Live shells and components MUST be found and picked up. You CANNOT leave explosives laying around outside where anyone can stumble across them. In some states it is the law to inspect the site at daylight the next day. The AHJ who issued the permit will follow up to make sure you were responsible enough to pick up any duds.
fredjr Posted October 12, 2014 Posted October 12, 2014 I have made a lot of shells of all different sizes. I have never crossmatched anything. I use a NC lacquer/BP (mill dust) mixture about the consistency of maple syrup. I put it into any empty elmers glue bottle. That makes it easy to put a dot on the end of time fuse, which is immediately pressed into some -20/+30 BP fines. When I make a rondelle using 1/32" or 1/16" increments in time fuse length this is the only way to get that kind of timing to work. Just don't believe that kind of accuracy can be done with crossmatching. For any shell over 6" I use multiple time fuses to ensure they break.
MrB Posted October 12, 2014 Posted October 12, 2014 Just don't believe that kind of accuracy can be done with crossmatching.I'm not sure what makes you say that.When using a punch, your times should be very consistent. If your sloppy when tying strands over the end of the timefuse, should that be the prefered method, then i can see how there could be issues with timing, but given the same method and care every time, it should provide consistent results.If your in doubt, check out "Fireworks Rocket Master 2013" at about 1:05:20 and forwards on Youtube. I don't care much for Dave, and his commentary, but He's got one thing right, TR is THE rocket master. If you can show him a faster, and more reliable way of setting up the time fuse, that gives a better result, i'm sure he's going to try it out. But claiming that it's not going to be accurate enough... He's going to laugh at you.B!
fredjr Posted October 12, 2014 Posted October 12, 2014 (edited) Are you calling a piece of black match tied across the outside end of time fuse cross matching? Because that is an elaborate priming method NOT cross matching. There is a reason he primes instead of crossmatching on time critical fusing... Edited October 12, 2014 by fredjr
nater Posted October 12, 2014 Posted October 12, 2014 TR was the master I was referring to who uses a slurry prime for time fuse. Priming in this way is still much more reliable than the plain cut ends of time fuse as was suggested by the original poster.
MrB Posted October 12, 2014 Posted October 12, 2014 Are you calling a piece of black match tied across the outside end of time fuse cross matching? Because that is an elaborate priming method NOT cross matching. There is a reason he primes instead of crossmatching on time critical fusing...Call it what you like. Dipping it in your NC/BP slurry is priming, while tying of quick-match, isn't, in my world. Fact remains the same. Punch, or tied, there isn't any problems with accuracy when it comes to timing. Unless you want to go in to semantics, about what "accuracy" means, in ways that currently eludes me, there is no if's or buts to it. You can decide exactly how long it should take your timefuse, from that it's introduced to flame, until it spits in the other end. TR was the master I was referring to who uses a slurry prime for time fuse. Priming in this way is still much more reliable than the plain cut ends of time fuse as was suggested by the original poster.Pretty much anything will be more reliable then cutting at an angle, and scratching the surface a little. B!
Mumbles Posted October 12, 2014 Posted October 12, 2014 I'm with Fred and TR on this. If you are punching or slitting the time fuse, you lose some of the accuracy. I don't know how to explain it, but it is a real phenomenon. Priming with a slurry or tying match over the top isn't affected in the same way for whatever reason. For what it's worth, I've usually heard tying the match over the top of the fuse referred to as top hatting or the top hat method. If I have critical timings with lengths less than 1/4", I would use priming or a top hat. If not, I generally stick with slitting and crossmatching. I guess there is no real reason for not just using priming all the time, but a few sticks of BM sticking out of the fuse feels like it will take fire better, though probably no different.
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