Small shell burst

[Swede]

I am making some simple shells for the fourth, and have read quite a bit about the need (with tiny shells) for a burst with a bit more oomph than BP.

 

I am thinking KP, Nitrate Flash, whistle, or benzolift as a burst. Which of these do you guys think will work best for 1.5" and 2.0" round shells, which will probably be rocket headers?

 

I'm leaning towards KP. Can KP be safely milled, or would it be best to screen or even diaper the K-perchlorate into the milled fuel mixture? As always, thanks!

[BLAST420]

I just whipped up a 3" paper shell and used a gram of whistle in the middle it had a nice "uhmmp"

 

http://youtube.com/watch?v=hZ3uCmwNYxY

[FREAKYDUTCHMEN]

I would go for the kno3 flash.

[frogy]

I am making some simple shells for the fourth, and have read quite a bit about the need (with tiny shells) for a burst with a bit more oomph than BP. 

 

I am thinking KP, Nitrate Flash, whistle, or benzolift as a burst.  Which of these do you guys think will work best for 1.5" and 2.0" round shells, which will probably be rocket headers?

 

I'm leaning towards KP.  Can KP be safely milled, or would it be best to screen or even diaper the K-perchlorate into the milled fuel mixture?  As always, thanks!  

Your KClO4 should already be pretty fine, just make sure that you use Air-float charcoal and screen the KClO4 through a 200 mesh screen on so...

 

KP works (on rice hulls 7:1) as a decent burst for even 1.75" shells, though it will give a rather unsymmetrical circular break... But it is still incredibly better than a straight Rough Powder\Crispies break.

 

I like to use Whistle mix in smaller shells, as it gives a near instant break, without the flash, and high ignition temperature.

 

Nitrate flash is more of a booster for larger shells if you ask me, since it tends to be slightly slower.

 

Perchlorate Flash and Benzoate Whistle would be my top choices.

 

 

I've had quite the success with granulated KP and whistle booster though.

 

Granulating the KP with 1% Red Gum instead of 4% Dextrin would probably give a faster burn rate.

 

Back to your question... Perchlorate should never be dry-milled with a fuel. You could mill it wet, but IMO that just makes a mess.

 

An added bonus though, you could probably subtract the binder and just granulate it with the water content from milling.

[mormanman]

I would go with slow flash. It has an umph but its not like a kaboom. Don't test it un-contained though b/c it doesn't tell you how powerful it is. I would test it with like a 1 in. aerial salute.

[Swede]

Wow, thanks for the prompt replies. I think am going to mix a small batch of whistle and KP + rice hulls. I can use the whistle to boost the KP, or alone. Between the two, I should be able to get some good performance. If not, it'll be dirty flash or something similar.

[crazyboy25]

I always use rocket whistle (the kind that has iron oxide and Vaseline.)

[frogy]

Granulate some 65/35/1/4 Benzoate whistle, or use anything between 60-70 and 40-30 as a powder booster... Whistle doesn't really depend on specifics when you are just using it as a booster.

 

KP 7:1 on rice hulls\corn\cripies alone is a decent break charge though.

 

Also stated above, it seems that Nitrate flash is very pressure dependent...

 

I've seen the same powder that burns like a flare in open air, report like 7/3 in a 1/8" thick tube.

[FREAKYDUTCHMEN]

KP 7:1 on rice hulls\corn\cripies alone is a decent break charge though.

 

Also stated above, it seems that Nitrate flash is very pressure dependent...

So is KP.

[FrKoNaLeaSh1010]

I dont like to use flash for shell breaks because I think the flash takes away from the shell. I always used straight whistle mix for smaller shells and kp on rice hulls or benzolift on rice hulls for larger shells.

[Bonny]

I've only built up to 3" shells. For my 1" cylinder shells I use whatever is laying around... meal D and or -20 mesh granulated BP (both from corning dust), star fragments, meal powder.

For my 3" ball shells I use meal coated vermiculite and about 1 tablespoon of whistle as a booster. For 3" cans I use my version of rough powder (pulverone) and no booster.

[Swede]

I mixed up some KP last night, a small test batch, 150 grams. While I was screening it, I did some thinking. Screening will never force an intimate mixture as well as ball milling does. So am I correct in saying well-screened KP is still more potent than expertly processed BP, with a good charcoal?

 

KP really seems to be nothing more than a perchlorate BP. I used the passfire formula, and since I have real SGRS, I used that, per Shimizu, rather than dextrin. We'll see how it works.

[frogy]

KP 7:1 on rice hulls\corn\cripies alone is a decent break charge though.

 

Also stated above, it seems that Nitrate flash is very pressure dependent...

So is KP.

I haven't found KP to be too pressure dependent...

Here's 1 gram or so of granulated KP, in open air...

 

http://youtube.com/watch?v=07jtxq_wjI4

 

 

I know what you mean about Nitrate flash detracting from the shell... It really matters for the effect though. For Charcoal stars, I like the bright flash in the center, but for Colors, I think a whistle break is much better.

 

I'm going to have to make some Benzolift soon.... I'm currently tired making BP in such small amounts.

[Swede]

Here's 1 gram or so of granulated KP, in open air...

 

http://youtube.com/watch?v=07jtxq_wjI4

That is exactly what my KP looks like, so I guess it'll work well. For the burst, is there any advantage to granulating, vs. simply coating rice hulls 7:1? I'm thinking the rice hulls will do two things - cushion the internals of the shell during lift, and also ensure potent ignition, since the hulls fill voids in the shell, and surround the stars themselves.

 

Not looking to be spoon-fed, I just enjoy talking about this stuff. I've had a few days off from work, and I've spent a lot of time here, as well as making pyro. Work sucks, hobbies rule. I want to retire!

[bogey1]

well i dont have any of the above chemicals, and only have until friday to come up with some sort of burst. my question is, if i pestal and mortar some fffg and add a little flash, would that be sufficient? (im using charcoal tiger tail stars and zinc stars) the zinc stars are cut without prime.

[TheSidewinder]

If you have FFFg, that alone will work for most shells.

[Mumbles]

It seems you have things pretty much figured out, but thought I might toss my two cents into the ring. I find I need to use a good charcoal to get the full potential out of the KP verses just a spill type of opening. Commercial airfloat just doesn't cut it. I normally use ground up cowboy charcoal to pass an 80 mesh screen. This time I used airfloat willow, so we shall see how they turn out. I coated puffed rice to cover the surface, so it's a bit of a two variable experiment. This is in bigger shells though. I've only made about 3 ball shells smaller than 3" I always used BP on hulls with some whistle booster, about a gram and they popped pretty good.

 

I've heard Eugene Yurek touting NC bound whistle granulated to -20 mesh as breaking small shells like this excellently.

 

With canister shells of this size I have been using -16+30 mesh good quality meal. and packing it in between the stars in place of polverone. They pop open pretty well too. For my spider inserts I tossed in a pinch of flash to get them to break a bit harder.

 

Good luck, and let us know how this works.

[bogey1]

If you have FFFg, that alone will work for most shells.

very good, i did not know that. should i leave the fffg as is or should i refine it to a "more finer powder" i just dont want my stars to blow blind

[Mumbles]

Finer powder increases the chances of them blowing blind.

[bogey1]

Finer powder increases the chances of them blowing blind.

thanks mumbles.. i'll report back with results and possibly some video....everybody have a safe 4th.. bogey

[Swede]

I'm milling some benzoate (alone! ) right now to reduce it to superfine powder... it'll become whistle, I've already got plenty of milled perc. Rather than using the fine mill powders in a little tissue bag in the center, I'm thinking about dilute NC lacquer-soaked vermiculite, placed in a PE container, and gently stirred/mixed. Hopefully the vermiculite won't clump too badly. I'm thinking this might be a good burst or boost, with excellent flame propogation and strong ignition for stars.