3 replies to this topic

[Burtgummer]

Hey everyone! I searched around but could not find any answers relating to my question. I've been making both spherical and cylindrical shells lately, but one thing has me concerned about my 3 finished cyclindrical shells. When I made them, I separated the very center of the shell from the outskirts of the shell (where stars are placed). Of course I filled the center section with granulated black powder and filled the gaps between the stars with black powder. However, the separator of the two sections of the shell is printer paper. It isnt extremely think and heavy duty, but it also isnt tissue paper. Now I can't stop wondering if my stars will ignite or not, because the paper might be too much of a barrier between the burst charge and the stars. Of course I can't open the shells back up to fix them now, but I'd like to know if anyone has done the same, and maybe I should change it before I make any more cylindrical shells.

Thanks!

[pyrotrev]

Bert: I don't think you'll have a problem (assuming the outside of your shells are properly spiked): once the inner core of BP lights, there'll be temperatures of >2,000C and pressures >1000psi inside that core - what price printer paper then? If you're worried about this in the future you can use a "canula" - a thin walled tube you withdraw after filling the core and between the stars with burst charge.

[karlfoxman]

You will not have a problem, my shells Canule's are made from 3 turns of Kraft. This is easily burnt away during the break.

[cooperman435]

Karl from what I can remember I thought from your demo at last years AGM that the cannule was removed after loading the centre? Was I just assuming wrongly?