39 replies to this topic

[Lil_Guppy]

I know a nail is a bit of a wierd ramming tool, but it was what I had at the time. It was filed nice and flat. I like to figure out what works with the tools I have at hand and then think about buying proper tools. It kind of a wierd way to go about it, but like Phoenix said, each to their own

[BurlHorse]

An alternative to spiking with string is to use long thin strips of pasted paper wound horizontally and vertically, this seems to be the favoured method in Chinese factories making stuff for Italian companies, and it can give a creditably even burst. If you can't be bothered to mess with all the gluey stuff I guess you could try that old gummed kraft tape you sometimes see in art/stationary shops... though I wouldn't advise licking to moisten it, one's mouth might get a little dry after the first metre or so.....

I like using gummed kraft paper/tape, for pasting round shells, I made a jig with 2 sponges so its wet when pulled through, TIP, Using 1 1/2" Gum Tape for shells, like 6"s and bigger, start the wrap from the time fuse ring, go ll the way around the shell, bottom, over top, back down to the fuse ring ovrlap about 1/4" , after youve gotten enough wraps to cover the shell x 1, take a sharpie, and write the numeral 1, start your next wrap right next to that, do the same as above and when you get to where you marked, your last wrapwill cover it, then mark numeral 2, easy to keep track of number of layers and produce repeatable shells..... End TIP Consistency pays off in manufacturing....

Keep up the good work,

Regards, Stay Green,

Bear

[BurlHorse]

OH, Be sure to smooth each wrap, and don't do more than four complete layers at a time before you let it dry for a day or two, then add layers until you get where you want.

Dialing in the burst to the number of layers takes practice, 12" shell of shells, for me is 5:1 BP Hulls, 10 Grams 70/30 whistle mix on the hulls, and exactly 16 layers of kraft, works for me.....

Regards, Stay Green,

Bear

[JamesH]

Heres a 2" ball shell I fired the other week. As can be seen from the video clip they still need dialing in, as they burst with poor star ignition. There was about 80 1/4" round D1 glitter stars in the shell but only about 1/4 of them ignited. The priming on the stars may be the cause of the problem. It was a very thin layer of ball milled meal that I forgot to add dextrin to, so that might be a factor.
The burst charge was 4:1 H3 on puffed rice and the shell was pasted in with 5 layers of 90gsm kraft. The delay was a 2 second spolette and the lift was 8g of 2fg equivalent BP.

Take a close look at the very first couple of frames of the burst - the priming seems to fire ok but then most of the stars seem to go out.
http://media.putfile...nch-round-shell

[Kevin J]

Would PVC be safe to use at least for mines and comets? There is nothing in the mortar that is supposed to be exploding then,( except for the lift charge of course).

[koobee]

I use pvc for mines and comets, but there is still the risk of something being too tight and the burst charge blowing your tubes into little bits. I take this risk from a distance in a concrete bunker. So far, no little flying pieces of plastic/

[Pretty green flames]

Would PVC be safe to use at least for mines and comets? There is nothing in the mortar that is supposed to be exploding then,( except for the lift charge of course).

This was discussed to some extent in the past, you might want to look here for some additional information.

[Kevin J]

Would there be some sort of strong/fiborus tape that you could wrat it with to make it safe? I wuld really like to be able to use them because it would make comets very easy. Just cut off a one inch long piece, fill it up, and let it dry.

[Pretty green flames]

If you'd burry it completely you would be pretty safe, or think sandbags and a very large safety distance.

[adamw]

There is nothing in the mortar that is supposed to be exploding then

Indeed, but what if it doesn't go according to plan! Just because it should not happen doesn't mean it won't. Think about these things!