shell timing

[Merlin]

I didnt get my 3 inch shell perfected for this fourth so we just used consumer shells. I know my time fuse was too short on my test shells now and I did not cross match the end on the inside of the shell only in the lift cup portion. It went up really well until it prematurely went off. I destroyed the other test shells realizing something was wrong with the time fusing. I know now I need to increase fuse length and cross match both ends and use an abundance of glue around and in the washer. Having said this I had to painfully resort to consumer shells this forth. 1.75 shells but they performed perfectly. Upon recovering the debris I see that the Chinese shielded their time fuse with a piece of grayish plastic inserted through the hemi. Does the 1/4 inch typical time fuse need shielding? See insert in attach photos/

 

Let me say without you guys comments I probably would have give up even before making decent BP! Thanks to pyrotechnician and especially grandmaster and all of you.

 

[pyrokid]

Priming both ends is important. You can probably get by most times without it but at the end of the day it's a cheap bit of insurance. An very respected pyro told me a story about priming the fire giving end of the fuse. Moral of the story: it's worth it to prime both ends

 

I'm not sure of the value of plastic shielding. I can say that I've never needed to use it. Your plastic shells may be different, as I've never used them.

 

Hope this helps.

[Peret]

1/4 inch time fuse doesn't need shielding. "Economy" fusing with Visco works if you roll the Visco with several turns of masking tape - note that the Visco must be wrapped all the way through the fuse hole to the outside of the shell. It's always a good idea to take a few inches of whatever fuse you use and time its burn.