DanielC Posted February 3, 2012 Posted February 3, 2012 I've been looking at the wasp pasting machines and I'm blown away by how quickly the shells are pasted and the amount of control the user has.I have a question however. Obviously the fuse hole is pasted over and from what I gather a small magnet is inserted and then cut out after pasting.My question is how is the timefuse or spolette inserted with the shell aready closed up tight. Do they just glue in a cardboard tube beforehand and shove the time fuse inside afterwards. What about spolettes or multiple time fusing. I saw a video on it and it looked as if there was only one fuse hole for a 12" shell.
allrocketspsl Posted February 3, 2012 Posted February 3, 2012 I've been looking at the wasp pasting machines and I'm blown away by how quickly the shells are pasted and the amount of control the user has.I have a question however. Obviously the fuse hole is pasted over and from what I gather a small magnet is inserted and then cut out after pasting.My question is how is the timefuse or spolette inserted with the shell aready closed up tight. Do they just glue in a cardboard tube beforehand and shove the time fuse inside afterwards. What about spolettes or multiple time fusing. I saw a video on it and it looked as if there was only one fuse hole for a 12" shell. better drill your fuse then if you want ignition each time!If i had a 16" shell no way would i use one fuse.
Mumbles Posted February 3, 2012 Posted February 3, 2012 No one drills their fuse. It's actually kind of a poor idea. Yes, inside the shell, there is a tube that runs from the hemi to the center of the shell. Ned Gorski calls it a passfire, but that is a term for a part of a canister shell. There is a Japanese word for it, but that is rarely used. This tube is generally filled with blackmatch, or granular BP or something before the fuse or spolette is actually inserted. Some people feel the need to anchor the fuse a bit as there is no pasted paper to support it. They take a short segment of cardboard tube and place it around the fuse, and fill it in with hot glue to make a sort of collet. The same thing can be done for two fuses. What some people have taken to doing is just making a larger hole, and placing two fuses in the same hole so that only one passfire is needed.
NightHawkInLight Posted February 3, 2012 Posted February 3, 2012 What some people have taken to doing is just making a larger hole, and placing two fuses in the same hole so that only one passfire is needed. I'm not sure I like that idea. Yeah I suppose it gives you the security of two time fuses, but there would be two triangle shaped holes along side where the fuses contact each other that would be filled with nothing but glue. Could be a failure point. One large hole is more prone to failure under pressure than two smaller holes. You can easily enough make yourself two entries if it's a shell with the time and effort put into it to warrant two fuses. I don't doubt that two fuses side by side could work just fine with a good glob of hot glue, I just think it's going a little lazy on something that's not hard to begin with. Also, I've grown to call anything that moves fire from one ignition point to another a passfire. Seems appropriate enough even if there are other traditional names. Anyway, you can get a good visual of what the tube looks like on the inside of the shell in this video: http://www.youtube.com/watch?v=j0T_59k6s1s When the fuse hole is located with a magnet after pasting, usually a razor blade is used to cut an opening, not a drill. Even when not using a wasp, some sort of passfire made from a tube or even just a length of quickmatch is usually extended from the end of the time fuse in larger shells so that the ignition point is in the center of the burst.
marks265 Posted February 3, 2012 Posted February 3, 2012 No one drills their fuse. It's actually kind of a poor idea. Yes, inside the shell, there is a tube that runs from the hemi to the center of the shell. Ned Gorski calls it a passfire, but that is a term for a part of a canister shell. There is a Japanese word for it, but that is rarely used. This tube is generally filled with blackmatch, or granular BP or something before the fuse or spolette is actually inserted. Some people feel the need to anchor the fuse a bit as there is no pasted paper to support it. They take a short segment of cardboard tube and place it around the fuse, and fill it in with hot glue to make a sort of collet. The same thing can be done for two fuses. What some people have taken to doing is just making a larger hole, and placing two fuses in the same hole so that only one passfire is needed. I remember the conversation with Ned calling it a passfire. I call the tube a match pipe. It just reminds me of quick match in design so I go with that. With that said I use blackmatch only because I always have the fear of the powder grains leaving the "match pipe". I was also shown putting a hole and magnet on top of the shell and then tuck a string inside for the lifting loop. I have only done the anchor method a few times. I think that is something I will start to do more often. I start to get the heebee-jeebee's thinkin' about relying on the hot melt glue.
Peret Posted February 4, 2012 Posted February 4, 2012 Ah, hot glue is safe because of the thermal inertia. Sure it will soften and melt easily, but it isn't in the lift flame long enough to affect anything except the outer surface. What troubles me more is when people say they use superglue to fix the fuse in flash inserts. For that job, I prefer a gap-filling glue, not one that hardens in a thin film, and I generally use epoxy rather than hot melt because it sticks to the fuse better.
Bacon Posted February 4, 2012 Posted February 4, 2012 Also superglue sometimes heats up while setting, I have no idea why. Not sure if its enough to light any comp but I'd still be a bit iffy.
marks265 Posted February 4, 2012 Posted February 4, 2012 I was more concerned about the time fuse breaking through and not really the glue melting. I guess maybe it is OK as I have not had a problem with shells up to 12 inch. Actually I think the hot glue would bond much better to the time fuse than I thought. The pasted paper to the time fuse seems less likely to bond to the time fuse threads. Super glue I think would be bad also because it can't flex and would break free too easily.
NightHawkInLight Posted February 4, 2012 Posted February 4, 2012 (edited) I'll second superglue as a dangerous option. I even thought about making a post about it a month ago, but the circumstances under which I was noticing problems were unusual. When the glue comes in contact with a surface that has been marked up with a Sharpie permanent marker it will become hot enough to start smoking. Not good. Who knows what other nasty reactions it might have with some of the usual pyro chemicals. Edited February 4, 2012 by NightHawkInLight
Peret Posted February 4, 2012 Posted February 4, 2012 I'd forgotten about that aspect of superglue, but now you remind me, a few weeks ago I was supergluing something and it got so hot it burned me. I didn't know it got hot up until then. I was more concerned that it's a thin film glue designed to stick perfectly mating surfaces, so if you use it to stick time fuse in a tube or plug it's very likely there will be unfilled voids to let hot gas in.
dagabu Posted February 4, 2012 Posted February 4, 2012 I have used around 20 gallons of "superglue" in my life and have witnessed several thermal reactions in cotton and rayon cloth and cotton balls where the temp reaches ignition after just a few seconds. This prompted me to get data from my manufacturer on thermal ramping and runaway thermal reactions. What I got from them was a chart of temps in relation to the amount of glue poured on a cottonball. The temps all stay below ignition temp of BP until a large portion of glue is used, say 5-6 grams. Also, there have been only a few chemical interactions that are hazardous whith the glue and was not aware of any problems with markers but will do some tests and see what my IR thermometer shows for temp rises. All in all, I would not use more than .5g of superglue at one time and would never use it to secure it in a shell but using a single drop on time fuse to bond it to cap plugs is fine and has no detectable heat rise when used sparingly. I have made thousands of timed reports now and have never had any thermal concerns. I have also run a few industrial assembly lines using auto feeders to apply superglue to rubber surfaces for bonding without a single puff of smoke. That's not to say that there is no risk but I feel it is manageable as long as you are careful and don't over do it. Sent from my iPhone after a long day of riding trails on snowmobiles. -dag
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