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Necessary to cross-match?


Merlin

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I just use a razor blade.

 

Edit: more precisely I use anvil cutters because they are always close by, which contain a long replaceable razor blade. You don't want to cut pyrotechnic composition like fuse with things like scissors because the metal on metal has caused ignition before and it wouldn't be good if the fuse was attached to something. Or you cut the first piece of time fuse on a 50 meter role and you watch it go up in smoke.

Edited by FlaMtnBkr
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I use one of these now.. a hammer punch. way easier than splitting the fuse ( for me)

original.jpeg

 

before I made these i just used a punch. like this.

original.jpeg

 

 

You will never be sad about buying either once you get to use them. :)

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  • 1 month later...
I made sixteen shells for the 4th all were cross matched the same. Four of the sixteen made return trips and all had the same issue. The cross match lit but did not ignite the time fuse. I had switched from tying the end of the split fuse closed to using a small zip tie. Is the zip tie the problem or is there something else going on.
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Did you have ONLY one strand? was it loose in the time fuse?

 

I punch all of mine double over a single strand and shove it through to make it snug. Put a dab of hot glue on one side of it to make sure it doesn't come out while i'm sealing the outside of the time fuse to the shell . Haven't had a round trip since I started doing it that way a couple years ago.. had a few come back while trying to just split the fuse... ( cheap skinny time fuse)

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I as well had issues with crossmatching this 4th. Of my 15 shells, 6 didn't light from the lift. I've never had this happen before when not crossmatching and honestly I'm still scratching my head as to what went wrong. I as well punched my fuse but only placed a single 1.25" long strand of black match through the hole (the diameter of my black match seems to be on the large size apparently) and hot glue in place. After finding a failed shell, it seemed the black match did light but didn't light the time fuse.

Edited by Rmholbert
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I fired 16 3 inch shells and 10 4 inch shells. I dont know where I got the idea or just made it up but. I use large drinking straws like you get at McDonalds. I punch- cross match the time fuse on the end that takes fire but I do it with ultra fast paper fuse. Then when all is hot glued in place I put hot glue on the inside around the time fuse. I then take measure from the base of the fuse inside the shell and cut a piece of the drinking straw so that when slipped over the time fuse the end will be at the center of the shell. Before I place it over the time fuse I cut three or four pieces of fast paper fuse and place inside the piece of straw and put over time fuse and bend down the excess fast fuse sticking out the top and tie, then I slip a piece of thin sandwich bag containing flash while I have the straw out of the shell twist that around the straw and fast fuse and tape with masking tape- then tie. Then I place the tied straw containing the fast paper fuse with flash bag secured over the time fuse and hot glue the straw at the base of the time fuse. The flash bag ends up right in the center of the shell. I have fired 26 consecutive shells with zero failures. You have to take proper precautions with the hot glue gun in the vicinity of flash. So my time fuse is not cross-matched on the inside at all. I guess you could say it is end-matched. That is for 4 inch shells. On the three inch ones I just fill a fuse protector about 1/2 full with flash and slip over the time fuse in the inside and crossmatch the fire end with a punch and fast paper fuse- very fast and easy.

Edited by Merlin
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I made a punch that makes some nice round holes in the quick match that just fits a piece of the white paper fast fuse. Going to test about a dozen of them and see what happens. The fit is fairly snug do you see any reason to hot melt the cross match in place?
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I made a punch that makes some nice round holes in the quick match that just fits a piece of the white paper fast fuse. Going to test about a dozen of them and see what happens. The fit is fairly snug do you see any reason to hot melt the cross match in place?

You mean holes in time fuse? I have not glued it because I think if the hot glue gets into the time fuse it could cause it not to take fire. If the fast fuse is really tight on a 3 inch I might let it go but with twice the materials in a 4 I tie the fast paper fuse to the time fuse after I pull it through tight or not.

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It wouldn't take much to tie it off just in case. Should I do anything more with the end in the shell? I was wondering if I should coat the end of the time fuse with a BP slurry or something. This fuse seems to be a bit lethargic it burns but its not real energetic.
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I dont use a slurry. I would take a couple pieces of the time fuse say 1 inch punch it, put the fast fuse in it and light it to see if it burns reliably. Your lift charge will definitely light the fast fuse. Just see if the fast fuse lights the time fuse. You need to burn a piece several inches long and time it precisely with a stop watch to determine the actual burn rate of the time fuse. Kill both birds with one fuse.

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The time fuse I have figured out its a pretty consistent 3.5 seconds an inch. I was more concerned about the time fuse lighting the burst charge. The burst end of it doesn't have a lot of spark to it and was wondering if I should do something to give it a kick.
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" I then take measure from the base of the fuse inside the shell and cut a piece of the drinking straw so that when slipped over the time fuse the end will be at the center of the shell. Before I place it over the time fuse I cut three or four pieces of fast paper fuse and place inside the piece of straw and put over time fuse and bend down the excess fast fuse sticking out the top and tie, then I slip a piece of thin sandwich bag containing flash while I have the straw out of the shell twist that around the straw and fast fuse and tape with masking tape- then tie. Then I place the tied straw containing the fast paper fuse with flash bag secured over the time fuse and hot glue the straw at the base of the time fuse. The flash bag ends up right in the center of the shell. I have fired 26 consecutive shells with zero failures."

Cut a piece of drinking straw the length you need to slip over the time fuse to reach the center of the shell. Place several pieces of fast paper fuse inside the straw so they stick out the top. Bend them down and tie with string. Put some fine BP instead of flash in a thin sandwich baggie and cut off excess and place over the straw with the fast fuse and tie. Now the time fuse will light the fast fuses which are in direct contact with your BP in a baggie. Of Course more BP is added to the hemis for proper burst. In a four inch shell I use 40 grams in the bottom and 40 grams in the top.

Just slip the drinking straw over the inside time fuse with several pieces of ultra fast paper fuse in the straw with the baggie and hot glue it at the base..

 

If you are making 3 inch or smaller shells get some black time fuse protectors from calebkessinger. Simply fill them half way with flash or very fine benzolift and slip them over the time fuse. Its quick and easy for small shells. Problem solved.

Edited by Merlin
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When precise timing doesn't really matter, I cut the end of the fuse on an angle. This exposes more of the core to spray fire. I also tie a piece of quickmatch over the end and run it to the center of the shell. This ensures a good fire transfer from the fuse, and the quickmatch sprays a lot of fire around. It's basically the same idea as a straw with BP or match in it, or the blackmatch nosing on a spolette. Lots of ways to skin a cat on this one.

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For clarification. I don't glue the crap out of the crossmatch with hotglue.. just touch a little to one side. Makes me feel better and keeps it secure.

 

The quick match is a great Idea, Thanks!

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It's basically the same idea as a straw with BP or match in it, or the blackmatch nosing on a spolette. Lots of ways to skin a cat on this one.

Oh, the skinned cat method doesnt transfer fire as well. Last time I got clawed and called it a day :o :P . I use the method of passfire with BM stuffed in the tube butted up to the fresh cut time fuse. Never had a failure this way, or the granulated powder in the passfire .

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I use the same method only with 4 strands of ultra fast fuse instead of blackmatch
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I use the same passfire method only with 4 strands of ultra fast fuse instead of blackmatch
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Before I decided to get into this hobby I had the perception that it was mostly chemistry and and physics. All I had to do was do my research and be meticulous in my execution. I have found this is not so, it truly is more of an art. The only thing universally agreed on is the ingredients and percentages of each in black powder. After that for every opinion on one thing you can usually find one that contradicts it. Its not because of contrariness its just that there is so many variables involved. I kind of had the idea that I wouldn't have to reinvent the wheel so to speak to get into this. But other than the fact that the wheel is generally round you are left to your own on the best way to execute it. Its going to be interesting.
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I was the same way. Chemist was my job title. Pyro is not spelled out as you would expect a lab analytical procedure in standard methods. It's all about finding what works for you and doing it consistently the same way. Kinda like shooting a muzzle loader but more complicated
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  • 2 months later...

I have noticed and have caught this when poking a hole through time fuse missing the core of the fuse. I am pretty sure this will cause a bring back. the only time that i had a bring back was in a canister shell, for some reason i have trouble getting the spoolett to burn right. Test results on the ground the spoolett burns accurett but in the air somethings not working right. Results = break on the ground.

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Oh, the skinned cat method doesnt transfer fire as well. Last time I got clawed and called it a day :o :P . I use the method of passfire with BM stuffed in the tube butted up to the fresh cut time fuse. Never had a failure this way, or the granulated powder in the passfire .

It transfers fire fine, it just transfer the fire (from the cat) to you. Or you could always put the cat inside a box with a Geiger counter and a vial of poison... so the cat is alive and dead.

 

I never skip cross matching. I did that one time and none of the shells took fire, or took fire with great delay.

Edited by taiwanluthiers
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i still time shells with gum tape wrapped visco. the 3mm safety fuse burns at 2.7 seconds per inch. 1 inch tape is perfect for 2.5"-3" shells and 1-1/2" for four inch shells(2.7 + 1.35 =4.05 seconds) with aggressive priming and this method has produced no round trips.

 

the last time fuse i had was that white chinese garbage that was only about 70% reliable even with ridiculous cross matching. it went in the burn pile. to pass fire to the inside, i just roll a 1/4" - 5/16" tube to reach the center of the shell, fill with b.p. rice hulls and seal with tissue (1 layer taped on top of the tube).

 

i would always crossmatch time fuse if i had some decent time fuse to use.

 

when i do cylinders 3 inch and up, ram spollettes.

Edited by rogeryermaw
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It transfers fire fine, it just transfer the fire (from the cat) to you. Or you could always put the cat inside a box with a Geiger counter and a vial of poison... so the cat is alive and dead.

 

 

LOl ..., you may have a point , maybe thats why I got the claws.

 

@ Roger: I too have had very bad experience with the cheap tan crap. Since then, always bought the good chinese stuff. Also, ramming your own Spollettes is the preferred method for canisters . Seem to be much stronger and take the spiking quite well.

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