chuck45 Posted November 23, 2011 Share Posted November 23, 2011 Hey Team, I'm looking into making shells, having been doing bottle rockets, starmines and also other ground pyro for a while. I like to be well informed. My question is; what type of fuse do you all use as your shell time fuse? I intend on having some homemade blackmatch with a short cannonfuse leader for the lift fuse. I am considering using my cannon fuse for the shell burst charge, it seems to be of good quality and stays lit when immersed. It is constructed of a pyrotechnic core, wrapped in metal strands and some thin paper as well. But I would like to know of other methods. I like to make eveyrthing as ideal as possible. I'm weighing up which will give the best product. Or should I suck it up and buy some thick visco from overseas? Thanks lads. Link to comment Share on other sites More sharing options...
nater Posted November 23, 2011 Share Posted November 23, 2011 I use some inexpensive Chinese time fuse. I've noticed most consumer shells use visco as time fuse, so that would work to. I'm confused though, do you intend to use bits of fuse instead of a burst charge? Or are the bits of fuse the stars? Link to comment Share on other sites More sharing options...
petroleum Posted November 23, 2011 Share Posted November 23, 2011 I use some inexpensive Chinese time fuse. I've noticed most consumer shells use visco as time fuse, so that would work to. I'm confused though, do you intend to use bits of fuse instead of a burst charge? Or are the bits of fuse the stars? I use only spollettes (ID=5 mm). Meal/KNO3/S mixture work well. Link to comment Share on other sites More sharing options...
Algenco Posted November 23, 2011 Share Posted November 23, 2011 different strokes for different folksSame applies to fuse, it's very difficult to use time fuse in 1.75-2" shells, for those I use ViscoWrap the Visco with a piece of masking tape to get the delay you want .75-1" wide, this section is placed inside the shell, this will stop the "side spit" from ingiting the burst too early3" and up time fuse or spoolettes Link to comment Share on other sites More sharing options...
Potassiumchlorate Posted November 23, 2011 Share Posted November 23, 2011 "Ordinary" delay fuse has caused flowerpots or burst just above the muzzle in 2" shells for me. Never had that problem with bigger shells, though. Link to comment Share on other sites More sharing options...
Mumbles Posted November 23, 2011 Share Posted November 23, 2011 I'm a little confused that you say your "cannon fuse" is wrapped in metal. Is this possibly a translational issue? The only fuse I know of that is wrapped in metal is thermalite type, and it probably wouldn't be a very good delay fuse. Link to comment Share on other sites More sharing options...
dagabu Posted November 23, 2011 Share Posted November 23, 2011 I like to use cheap Chinese Visco wrapped in aluminum tape and cut at an angle and dipped into fencepost prime. The timing has been just great and the fire spit will light anything. -dag Link to comment Share on other sites More sharing options...
50AE Posted November 23, 2011 Share Posted November 23, 2011 I use chinese time fuse only.I don't see a problem using time fuse in 2" shells. I've been top and bottom fusing cylinder shells without issues. Link to comment Share on other sites More sharing options...
dagabu Posted November 23, 2011 Share Posted November 23, 2011 I use chinese time fuse only.I don't see a problem using time fuse in 2" shells. I've been top and bottom fusing cylinder shells without issues. In ball shells, I just don't have the dexterity to work with cross punched time fuse that is only 3/4" from punch to punch. -dag Link to comment Share on other sites More sharing options...
50AE Posted November 23, 2011 Share Posted November 23, 2011 You don't have to punch in both sides. What I do, is I slice the outer side and put BM strands in it. I don't touch the inner side, but I add a passfire tube and i put BM strands into it. The BM then only touches the time fuse. Fired about 80 shells this ways ranging 2" to 5" without failure.About 26 shells 2"35 3"17 4"2 5" Link to comment Share on other sites More sharing options...
Potassiumchlorate Posted November 23, 2011 Share Posted November 23, 2011 (edited) I don't crossmatch. I just cut the timefuse oblique, so that a larger area of the BP is exposed. This works for me. Only thing is that the shell has to be fired within some weeks at most, otherwise the fuse will absorb moisture and fail to ignite. I have bought some plastic spolettes, though, that fit predrilled holes in some 6" hemispheres that I bought. Only thing is that the hemispheres are of paper, so I hesitate to bottom fuse them. I have never top fused a shell, but it doesn't seem to be a problem. The flame from the lift charge lights it anyway, as far as I understand. Edited November 23, 2011 by Potassiumchlorate Link to comment Share on other sites More sharing options...
50AE Posted November 23, 2011 Share Posted November 23, 2011 Top fusing is done by making the quickmatch passfire pass by the time fuse before igniting the lift charge. This way the time fuse is ignited first, then a few milliseconds afterwards the lift charge. Link to comment Share on other sites More sharing options...
Potassiumchlorate Posted November 24, 2011 Share Posted November 24, 2011 Top fusing is done by making the quickmatch passfire pass by the time fuse before igniting the lift charge. This way the time fuse is ignited first, then a few milliseconds afterwards the lift charge. I know that that is often done, but I have also heard from several pyrotechnicians that, since there is a gap between the shell and the mortar, part of the flame from the lift charge will reach around the shell, before the shell leaves the mortar, and ignite the top fuse anyway. Right or wrong? Seems logical. The burn rate of the BP should be higher than the muzzle velocity of the shell, shouldn't it? Link to comment Share on other sites More sharing options...
nater Posted November 24, 2011 Share Posted November 24, 2011 (edited) The flame from the lift definitely beats the shell out of the mortar. I don't doubt that it would light a primed time fuse, comets and rising effects light just fine most of the time. Assuming the shell has a normal leader, why not tie it off to the time fuse with a bucket anyway for extra insurance? http://www.youtube.com/watch?v=OdJSr4i3aNM Edited November 24, 2011 by nater Link to comment Share on other sites More sharing options...
Potassiumchlorate Posted November 24, 2011 Share Posted November 24, 2011 There you could really see that it was the way I said, though. Link to comment Share on other sites More sharing options...
nater Posted November 24, 2011 Share Posted November 24, 2011 There you could really see that it was the way I said, though. Right, I was agreeing with you that the flame from the lift engulfs the mortar before the shell lifts. I've never seen tails and rising effects on commercial shells fused into the leader, they light from the gasses from the lift. Like I said, since it is so important to light the time fuse on a shell, why not use a bucket to attach the leader to a top fused shell? It will most likely light anyway, but I would rather have the insurance of direct fire into the primed fuse than the chance of a shell making a round trip. Link to comment Share on other sites More sharing options...
Potassiumchlorate Posted November 24, 2011 Share Posted November 24, 2011 You're right. Link to comment Share on other sites More sharing options...
Peret Posted November 24, 2011 Share Posted November 24, 2011 I've used Visco wrapped in masking tape for smaller shells with great success but it's important to time it, as Visco isn't consistent from batch to batch. I timed one batch, then set it aside only for fusing. I cut the bottom at an angle and just leave the top the way it is. I had one or two failures from priming the bottom with powder and NC, since the acetone dissolves the NC on the fuse, but I never had a failure unprimed. Now I have adequate supplies of good quality 1/4 inch time fuse I use it for everything. I cross match the bottom and use a tube inside stuffed with black match, as 50AE described above. I've never had one of these fail. I know spolettes have their enthusiasts, but I'd be concerned about consistency if I made my own. With proper time fuse I know it's going to burn 3 seconds per inch. With spolettes I'd have to make 100 and batch test 20 of them to have the same degree of confidence. Link to comment Share on other sites More sharing options...
chuck45 Posted November 24, 2011 Author Share Posted November 24, 2011 Thanks for all the help guys. I'm sorry for the clarity of the post, I must have been very tired last night, I've been up late all week completing Uni work. Yes my fuse is the thermalite type. I was thinking the same, that it probably wouldn't be great. From what y'all have told me, I think I will use some visco, the only issue I have is the overseas delivery to Australia, the police state extravaganza where lasers are prohibited weapons. I do have bottle rocket tubes I could use to make spollettes, I could adjust the timing by changing the composition. I think my first shells will be 1.75 inch as I have the hemis and mortar to suit. Cant wait until I have some free time! Link to comment Share on other sites More sharing options...
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