Merlin Posted June 29, 2014 Posted June 29, 2014 (edited) I dont understand the purpose of enclosing the fuse in a "leader". It is just a paper casing. Since the lift is enclosed in a lift cup what purpose does enclosing the fuse serve? Also, how do you connect the initial piece of visco ( for escape time) to the fast burning fuse? I just taped them together and the visco burned out and the fast fuse did not ignite.I then, after sufficient time, I pulled the shell and refused it with only visco. I took quite a while to go off of course. The fast fuse is about the same size as the visco 1/8th inch so surely you dont split and splice them together?Sans all else I can use a remote nichrome igniter on the fast fuse and remotely fire the mortar by radio control. I just dont understand the fusing procedure.I know I am ignorant but what better way than to ask the experts? Edited June 29, 2014 by Merlin
pyrokid Posted June 29, 2014 Posted June 29, 2014 Real professional shells with leaders have quickmatch, which is BP coated onto cotton string, inside a paper tube. This is designed to burn instantaneously or at least very fast. If you're making your own shells you want to have access to quickmatch. It sounds as though you are using one of the internet methods of enclosing fast Visco in a paper tube. I've always been skeptical of this. However, since you're using two Visco type fuses, standard procedures for connecting those fuses apply. I prefer electrical tape, and you want at least an inch of parallel contact between the two fuses, with a snug piece of tape holding them together. The end of the fuse taking fire should face the direction the fire comes from. It's best to avoid the use of slow Visco for the entire length of the shell fuse, due to the uncertainty it creates.
schroedinger Posted June 29, 2014 Posted June 29, 2014 Maybe you can post a picture of the fast fuse you are using? But like said before you want a quichmatch, do you know how to make black match? Thats the best point to start with. Most fuses will light from visco if you tape em together for about an inch. The purpose of paper wrapping is to increasethe burn speed. This doesn't work for coated fuse types, these are just coated to protect the mortar from theside spit off a slow burning fuse
dagabu Posted June 29, 2014 Posted June 29, 2014 I dont understand the purpose of enclosing the fuse in a "leader". It is just a paper casing. Since the lift is enclosed in a lift cup what purpose does enclosing the fuse serve? Also, how do you connect the initial piece of visco ( for escape time) to the fast burning fuse? I just taped them together and the visco burned out and the fast fuse did not ignite.I then, after sufficient time, I pulled the shell and refused it with only visco. I took quite a while to go off of course. The fast fuse is about the same size as the visco 1/8th inch so surely you dont split and splice them together?Sans all else I can use a remote nichrome igniter on the fast fuse and remotely fire the mortar by radio control. I just dont understand the fusing procedure.I know I am ignorant but what better way than to ask the experts? Qiuckmatch, or QM from here on out, is a two part mechanism. The paper tube is a 'pipe' that allows for slight compression which allows a "flame front" to propagate down the pipe well ahead of the burning center of the Blackmatch (BM). This flame front can reach speeds of several hundred FPS when no restrictions are in its way. Once the BM is removed from the pipe, the flame front ceases and the BM becomes just BM and burns about as fast as standard Visco. The correct way to use visco in a paper pipe (QM) is to insert the visco about 1" into the pipe, fold over the extra paper to cover the exposed BM and use masking tape to seal and fire proof the BM. Why? Other operators can tell you stories where a spark, ember etc. have fallen on to exposed BM and the shell fires immediately, no time to move or react. We call visco, chicken-wick.
nater Posted June 29, 2014 Posted June 29, 2014 I had typed and deleted it thinking I was quickly getting way over the poster's head. QM burns ~86 ft/s and bare BM should burn about 3-4 seconds per inch. I do not like visco leaders when hand lighting. I typically leave a little black match exposed and cover it with a safety cap. This gives me time to turn around and duck my head before the shell lifts. DISCAIMER!!: I regularly hand light displays and am comfortable being very close to 6" and under shells lifting. I do not recommend this practice to those without the proper PPE, training and knowledge of the product they are firing. I do not like visco on display shells, it is harder to keep pace and burns too slow. For homemade shells, I often tie a bucket to the spolette and drop a shrouded ematch in the bucket. This way I can be far enough back to film without using a long delay. Rockets just get a few inches of visco and handlit.
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