jwitt Posted May 5, 2010 Posted May 5, 2010 So I have a roll of white chinese time fuse. It specs out at "about 3.25 seconds per inch." That equates to .307 inches per second. Started testing tonight. My time measurements appear to be accurate to roughly .01 seconds over my trials. I have a burn time of .212 inches per second. That equates to 4.717 seconds per inch. You guys said this stuff wasn't the highest quality, but man that's a pretty big difference, no? To time my 3" ball shells to 2.75 seconds, I need .583 inches between cross matches. Wowzers. That doesn't extend the fire very deep into the shell, so my passfire tube needs long pieces of blackmatch to reach out and ignite the burst. That's actually pretty inconvenient to work with! Argh! Hopefully my other roll of time fuse, chinese stuff with some red string binding, will be better. On to making a prototype completed fuse assembly.
Xtreme Pyro Posted May 5, 2010 Posted May 5, 2010 (edited) So I have a roll of white chinese time fuse. It specs out at "about 3.25 seconds per inch." That equates to .307 inches per second. Started testing tonight. My time measurements appear to be accurate to roughly .01 seconds over my trials. I have a burn time of .212 inches per second. That equates to 4.717 seconds per inch. You guys said this stuff wasn't the highest quality, but man that's a pretty big difference, no? To time my 3" ball shells to 2.75 seconds, I need .583 inches between cross matches. Wowzers. That doesn't extend the fire very deep into the shell, so my passfire tube needs long pieces of blackmatch to reach out and ignite the burst. That's actually pretty inconvenient to work with! Argh! Hopefully my other roll of time fuse, chinese stuff with some red string binding, will be better. On to making a prototype completed fuse assembly. I remember that white chinese fuse to be pretty inconsistent as far as burn rates go. I use the stuff with the red string coiled around it, and it seems to be pretty consistent if I remember correctly it was something like ~3.2 seconds an inch, your roll may be different though. Is this the stuff your talking about? http://www.pyroguide.com/images/c/cc/Time_fuse.jpg Edited May 5, 2010 by Xtreme Pyro
jwitt Posted May 5, 2010 Author Posted May 5, 2010 Yep, that's the "good stuff" I need to test my white stuff midway through the roll I guess, and again at the far end. Anyway, prototyped my "shell timing/ignition complex" and it works like a charm. Totally original...exactly like Ventsi's tutorial. That blackmatch blows out the end like a stuck pig! Made a dimensioned drawing so it's repeatable- and the dimensions reflected the times of 3.02 sec, 2.81 sec, and 2.74 sec. Yeah
Ventsi Posted May 5, 2010 Posted May 5, 2010 Glad to hear that it worked out for you. The only difference I've noticed between the red/white vs. the all white string is that the all white stuff is harder to light. This has only troubled me with touch priming inserts, x-matching works charmingly however and I've had more than a dozen or so shells go up and not one fail yet. Again, I believe the right technique to igniting the fuse is key.
angelluis Posted October 3, 2010 Posted October 3, 2010 So I have a roll of white chinese time fuse. It specs out at "about 3.25 seconds per inch." That equates to .307 inches per second. Started testing tonight. My time measurements appear to be accurate to roughly .01 seconds over my trials. I have a burn time of .212 inches per second. That equates to 4.717 seconds per inch. You guys said this stuff wasn't the highest quality, but man that's a pretty big difference, no? To time my 3" ball shells to 2.75 seconds, I need .583 inches between cross matches. Wowzers. That doesn't extend the fire very deep into the shell, so my passfire tube needs long pieces of blackmatch to reach out and ignite the burst. That's actually pretty inconvenient to work with! Argh! Hopefully my other roll of time fuse, chinese stuff with some red string binding, will be better. On to making a prototype completed fuse assembly. I have the same time fuse and all I do is cut a straw and hot glue it to the time fuse then fill my time fuse with some 4fa or even meal d and then put a very little rolled up ball of tissue at the tip when the time fuse burns trough it gives the same effect as a spolette this gives me the lenth that is needed to reach the burst this actually works well! give it a shot!
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