Aerial Shells

[nath0r]

Garden twine should be fine (im not a poet) ive seen people use it on can shells and they function fine

[TheSidewinder]

"Garden Twine" is such an inspecific description that you really can't make any assumptions about it.

 

If it's the typical "Garden Twine" I've seen in Menards and similar places, it won't work very well at all. It's not strong enough, and too thick. If I built a shell using that stuff, and all other specs being "normal", I'd end up with a too-tight fit in the mortar and that's not a good thing. As well, I wouldn't get the correct degree of confinement during the burst phase. The shell would rupture too soon, resulting in a poor pattern.

 

You should be able to break a single strand of whatever you use, with two gloved hands, but not easily. I have both Flax and Hemp twine, and they're great for spiking. I can JUST BARELY snap the Hemp twine, and the Flax twine isn't far behind.

 

If you can break the nylon string with your hands, give it a try. But be aware of the pollution. The stuff doesn't biodegrade.

 

Good luck.

[nick2354]

Sorry I wasnt specific enough.

 

It is Green Jute Twine.

 

http://www.hardwarestore.com/media/product...29_front200.jpg

 

Its rather thick.

[TheSidewinder]

I suspect that won't be strong enough, and it looks really thick. If you start with a slightly undersize shell, before spiking, it might be OK. But you might get too-little confinement with it.

 

Like so many things pyro, though, you won't really know until you try it.

 

Can you break it easily with your hands? If so, I'd spike with twice the number of turns than you'd normally use.

[oskarchem]

I use a twine that stinks like goat . But have no idea what it's called...

[TheSidewinder]

If it smells like goat piss, it's probably Flax.

 

My roll of Flax smells like that. On a humid day, it's downright repulsive.

[FREAKYDUTCHMEN]

Hemp stinks, flax doesn't really.

A mistake that very often is made.

[FrankRizzo]

Hemp stinks, flax doesn't really.

A mistake that very often is made.

In the U.S., it's the other way around. Both are made from fibers that are processed via retting so both have the propensity to stink like horse/cow shit. The hemp sold here is used mostly for the handcrafted jewelry market, so it tends to be better finished and not stinky.

[psyco_1322]

Is hemp a good alternative to flax for spiking canisters? I dont feel like ordering flax. I have a big roll of cotton/polly but its knda thick and I would rather use something thinner. Plus coating the string in glue to help it out isnt so fun. Hemps got to be some kind of improvement.

[Richtee]

. Plus coating the string in glue to help it out isnt so fun.

What schmearing some glue on after spiking? Seems easy enough.

[FrankRizzo]

Is hemp a good alternative to flax for spiking canisters? I dont feel like ordering flax. I have a big roll of cotton/polly but its knda thick and I would rather use something thinner. Plus coating the string in glue to help it out isnt so fun. Hemps got to be some kind of improvement.

Yep. Use 12-ply (48lb) hemp twine. You can use the the 20lb stuff in two strands to keep the thickness down if making multibreaks.

[psyco_1322]

What schmearing some glue on after spiking? Seems easy enough.

Well not really after spiking but before. I usually have my brother help out with it. Pull a few feet off the horse and he goes along and smears glue up and down the string before its spiked onto the shell.

[Richtee]

Well not really after spiking but before.

Sooo why before? Seems easier after... or am I missing something? Could be... still brain addled from the B-day cannister I think.

[ULTRABUF]

I believe paste is applied before spiking so that when it dries it shrinks tighter around the shell.

[TheSidewinder]

Methods vary, but the result you want is that the wheat paste gets absorbed by the spiking twine. As it dries, the twine shrinks further making for a tighter spike.

 

It's somewhat of a balancing act, too, as you don't want to get TOO much paste on the shell, especially if you put your last turns of Kraft over the twine as I do. I smear a bunch of paste on the shell after spiking, working it into the twine, "strip" off as much as I can after a few minutes, then add my last turns of pre-pasted and broken-in Kraft over the spiking.

 

I should note that I've already put a turn of masking tape over the timefuse to prevent infiltration of moist paste into the fuse.

[Yankie]

I need help with my rising comets, they never light, I used C6 and the ends were rough so I figured they would not need priming, would this be my problem? I just cant think how it can be that hard to light, considering I used smooth rolled stars that are harder to ignite than C6 in shells and they work fine.

[TheSidewinder]

From what I've seen (although I've never made any) they normally don't have ignition problems, but I suppose it's possible.

 

What I've read/heard some folks do is take a aharp knife tip and "scratch" the exposed surface of the comet repeatedly until it's REALLY rough.

 

You could also prime them with some commercial 2Fg. I can't see how they could possibly fail to light if you did that.

 

Your problem puzzles me, too. Perhaps some of the more experienced folks will chime in here? (hint, hint )

[psyco_1322]

I suspect this is on a ball shell. Just put a dab of nc lacquer on the end of it and then press it into some fine granulated bp, 2 or 3fg works great. If you dont have it you can just use some homemade stuff.

 

I had a 3" ball shell full of pop glitter and had some extr stars left over. So I attached the around the top of the shell as rising tails. About 5 3/8" cut stars, primed and everything. Seemed every star in the shell lit just fine, though not one of them stars on the shell caught fire. Weird.

[ULTRABUF]

Well I wouldnt really call myself a "experienced member" lol but heres a thought. Theres a chance that they might not have been sealed completely at the bottom and burned from both ends very quickly before it even exits the mortar. Thats a problem I've been having, only about half my rising comets have worked.

[Bonny]

I find it hard to believe that a comet could burn out before the shell exits the mortar. Do you fuse to the comet and then BM to the lift? Or, do your shells launch in slo-mo?

 

For rising comets on my 3" ball shells I've used Shimizu willow + 10% Ti curls primed lightly in meal powder and they all lit fine.

I used to also add leftover TT stars to 1" cylinder shell by simply gluing them on top and the lift gasses always fired them up no problem.

 

Another way to prime the comets, similar to what psyco_1322 said is to use a BP/NC or even BP/water slurry then dip into some granulated BP.

[ULTRABUF]

You are right, it may not burn before it exits the mortar but if its not properly sealed on all sides but the top its effect is probably lost in the huge fireball shooting out of the mortar, and by the time thats gone, yes its very possible for it to have burned out. If its not sealed along the sides or the bottom then the burn time will decrease substancially.

[Bonny]

You are right, it may not burn before it exits the mortar but if its not properly sealed on all sides but the top its effect is probably lost in the huge fireball shooting out of the mortar, and by the time thats gone, yes its very possible for it to have burned out. If its not sealed along the sides or the bottom then the burn time will decrease substancially.

I guess it is possible for the comet to burn up and be lost in the lift fireball if not sealed properly around the sides, but that would mean you are making EXTREMELY fast burning comets.

Even when I shoot the same comets from a tube, with all sides exposed they burn nicely up to at least 50ft, probably closer to 75 ft.

[tentacles]

I agree with Bonny here, I don't see how a comet could burn so fast (if it's appropriately sized for the shell) unless it's cracked or breaks apart on firing. I know there are comet formulas intended to be wrapped, etc. The BP + Ti comets could possibly burn this fast if you used fast milled bp.

 

Bonny, had a chance to use that comet pump? Does it work okay?

 

I generally hot glue my comets on, the trick is to be sure to work the glue into the comet before sticking it on. If the surface the hot glue is going on doesn't get warm enough, it doesn't stick very well. Maybe your comets are actually falling off at lift and/or breaking up?

[FrKoNaLeaSh1010]

I think the comet either wasn't binded properlly and got blown apart or perhaps you had a very hard lift and it didn't ignite that way. As said before I would suggest priming the top with some granulated bp and it should work fine. C6 lights fairly easily and i've never had to prime them but if your using large lift charges they might be slightly overpowered and thus cracking/destroying the comet or just burning too fast to get proper flame propagation to the comet top. Prime it and try again and let us know. also is it possible that you messed up the ratios when u made the comet? did you make others that worked from that same batch?

[Bonny]

Bonny, had a chance to use that comet pump? Does it work okay?

 

I generally hot glue my comets on, the trick is to be sure to work the glue into the comet before sticking it on. If the surface the hot glue is going on doesn't get warm enough, it doesn't stick very well. Maybe your comets are actually falling off at lift and/or breaking up?

Which one...you made me 2 pumps. I have used both and they work well. The smaller one tends to flex a bit if I use the clamp to press it, but I've probably pumped 30 or 40 comets with it. The other one works great too, but I think the comets might be a a bit too tight of a fit in the tubes I have. The comets did fire, but I blew the sides out 2 tubes. I was trying to make them like a candle with (IIRC) 4 shots each. Too much lift is anoher suspect in this one.

 

I also hot glue my comets and then paste (if i have it handy or just masking tape to cover the seam where it joins the shell. I think it would be very difficult to break a comet with the lift charge if it's on top...you are putting the comets on top of the shell right??