First 6": Top or Bottom Fuse?

[xBangergoosEx]

I am building my first 6" ball shell, and i am wondering if i should top fuse it using a passfire or if i should bottom fuse it like most smaller shells (where the fire from the lift charge ignites the time fuse, etc.). I am particularly nervous about this shell because a great deal of raw materials, time, and effort is going into it and i would hate for it to flowerpot.

[dagabu]

I am building my first 6" ball shell, and i am wondering if i should top fuse it using a passfire or if i should bottom fuse it like most smaller shells (where the fire from the lift charge ignites the time fuse, etc.). I am particularly nervous about this shell because a great deal of raw materials, time, and effort is going into it and i would hate for it to flowerpot.

 

Cylinders I like to top fuse, ball shells, never seen it done. Anybody here ever top fused a ball shell?

 

-dag

[Mumbles]

The only ball shells I've ever seen top fused were 36" in diameter. I believe Ned or someone may prefer to top fuse when using spolettes as well in 12" or so. A 6" will be fine. I've bottom fused every 6" ball I've ever made including when I made the mistake of lifting one with 10% by weight of commercial 4FA. Don't do that.

[californiapyro]

haha ohhh geez. wow, that shell must've gone to the moon

[Potassiumchlorate]

I have made two 6" this far, bottom fused. I considered making top fused this year, since I have spolettes now, but it turned out that the spolettes don't fit in the holes, so I will drill holes and bottom fuse with an ordinary delay fuse instead.

 

They used to top fuse all shells back in the 19th century, though, from what I've understood. We discussed it in another thread.

Edited December 21, 2011 by Potassiumchlorate

[dan999ification]

i only top fuse my cans if they are to be lifted hard, come to think i never saw a top fused ball shell before, certainly the bigger ones have paste/glue soaked string wrapped around the one or two fuses allowing the fire/pressure to pass the weak spot, rigidity is as important you need to pack it solid.

take your time

 

dan.

[cogbarry]

haha ohhh geez. wow, that shell must've gone to the moon

 

..or maybe not. What did happen mumbles?

[Mumbles]

It didn't go as high as I would have thought, but it made a hell of a bang when it exited the gun. I was almost positive I had blow up the fiberglass gun, though it was fine. It got higher than normal, maybe 700-800 ft, and was still traveling up when it went off.

[cogbarry]

It didn't go as high as I would have thought, but it made a hell of a bang when it exited the gun. I was almost positive I had blow up the fiberglass gun, though it was fine. It got higher than normal, maybe 700-800 ft, and was still traveling up when it went off.

 

Ah, glad the shell and gun survived.

[Algenco]

Dan Creagan says he top fuses ball shells sometimes.

It might prevent a few "flowerpots" that way

[Bonny]

For a 6" ball, just botton fuse it. As long as the shell is well made (nice and full) and well pasted you have nothing to worry about. The (chinese) shells I've worked with up to 12" are all bottom fused.

[DanishPyro]

I would also just go for the bottomfusing, as long it only is 6" shells, when they get double the size - or even bigger, i would start considering about top fusing them, but it won't get a problem as long as you ensure the fuse properly. :-)