Perchlorate Bursts

[lodcomm]

Hello Folks,

 

I see several references to perchlorate based burst charges.. I am looking for some general input/experience on your preferred composition. I see a few different formulas, most being shimizu comps. KP, no5, no44 etc. I most often see experieced pyro's refering to KP burst. What is the advantage this formulation (kcl04,charcoal,sulfur) vs say no5 - which is simply kcl4+charcoal? (I understand the absence of the sulfur would make the composition slightly less friction sensitive, however I assume there are some advantages to having the sulfur in the KP formulation)

 

 

thanks.

Edited August 11, 2009 by lodcomm

[Mumbles]

The sulfur both decreases the ignition temperature, as well as increasing gas output and burn speed. This means it is better for smaller shells. I've used it down to 2 or 3" shells. Though, it lacks some power at that small of shells.

 

No. 5 I've heard is good for larger shells. A guy I know says not to use it for anything smaller than 10" peony single petals. He also likes very hard bursts. I'd say it'd be good down to 6" or 8".

 

No. 44 is simply No. 5 with +5% dichromate. It's almost as powerful as KP. I find it isn't as pressure sensitive though, so to get the needed compression, it needs to be used in larger shells. I used it in an 8" double petal, and it really broke it nicely. I used it in a few 6" shells, and it just didn't have the same pop. One was a double petal, and the other had some pretty big stars, so there may not have been enough volume. A bit of extra pasting could have done it though probably.

 

i got another from Eric Hunkins:

 

Perc - 70

Charcoal - 11

Potassium Benzoate - 15

Binder - 4%

 

I'm sold on it. It broke my 3" shells very nicely. It seemed the video of some 5" he shot broke pretty nicely too. His original notes said sodium benzoate I think. You can vary the amount of Charcoal to benz to vary the power.

[lodcomm]

The sulfur both decreases the ignition temperature, as well as increasing gas output and burn speed. This means it is better for smaller shells. I've used it down to 2 or 3" shells. Though, it lacks some power at that small of shells.

 

No. 5 I've heard is good for larger shells. A guy I know says not to use it for anything smaller than 10" peony single petals. He also likes very hard bursts. I'd say it'd be good down to 6" or 8".

 

No. 44 is simply No. 5 with +5% dichromate. It's almost as powerful as KP. I find it isn't as pressure sensitive though, so to get the needed compression, it needs to be used in larger shells. I used it in an 8" double petal, and it really broke it nicely. I used it in a few 6" shells, and it just didn't have the same pop. One was a double petal, and the other had some pretty big stars, so there may not have been enough volume. A bit of extra pasting could have done it though probably.

 

i got another from Eric Hunkins:

 

Perc - 70

Charcoal - 11

Potassium Benzoate - 15

Binder - 4%

 

I'm sold on it. It broke my 3" shells very nicely. It seemed the video of some 5" he shot broke pretty nicely too. His original notes said sodium benzoate I think. You can vary the amount of Charcoal to benz to vary the power.

 

 

 

Thanks for the reply.

 

I think I will play a bit with the Hunkins composition. I have a good quantity of Sodium Benzoate on hand in the chem bin. I work mostly with 3" & 4" shells. What binder do you prefer with this - and do you rice it or simply granulate it for your bursts?

 

How about using this (or a variation) as a lift composition as well - any thoughts?

 

thanks again

 

todd

Edited August 11, 2009 by lodcomm

[Mumbles]

I coated it 5:1 on rice hulls. I use dextrin to coat all my media.

[lodcomm]

I coated it 5:1 on rice hulls. I use dextrin to coat all my media.

 

5 parts burst : to 1 part dry hulls by weight?

[Mumbles]

Yes. I normally put the binder into 4 or 4.5 parts of it, and leave it out of the last increment. I add this binderless layer last to help them to keep from sticking together.

[The-T]

Im looking for fairly hard breaks for 3" shells. Do you guys think Hunkins comp might do?

[Mumbles]

I think that you will be satisfied with it. I blew a bunch of stars blind, but the few that did light were thrown a pretty considerable distance, and it gave a good pop. I used 7 layers of 35# gummed kraft to paste them in.

[TrueBluePyro]

Im thinking of useing this Eric Hunkins formular, just for a try:

 

Perc - 70

Charcoal - 11

Potassium Benzoate - 15

Binder - 4%

 

Im pretty sure it is a bad idea to ball mill any perc formular, so just simply screen it?

 

Does anyone want to explian how this formular works chemicly? how does the k benz help.

 

How would KP compare to this formular?

[Ralph]

its a bit like benzo lift (with out any sulfur) and yeah not a good idea to ball mill it considering it is pretty much whistle mix with added charcoal i found it wasn't to easy to ignite though a fuse did it it wasn't like bp and in open air it was slow

[Mumbles]

I'd imagine it is stronger than KP. It seemed to break harder in the smaller shells I tried it in. I've yet to shoot any 5 or 6" with it, where I'd really be able to compare.

 

All of these perc bursts burn slow in open air, relatively.

[Swede]

i got another from Eric Hunkins:

 

Perc - 70

Charcoal - 11

Potassium Benzoate - 15

Binder - 4%

 

I like the looks of this formula. It should be a decent burst, with good ignition characteristics. I'd suspect that by altering the proportions of charcoal and benzoate, you can have an almost variable burst in terms of strength. "Dial-a-burst" by varying the proportions... sort of like the "Dial-a-yield" tactical nukes we had in the Air Force! "Hmm, do I want 10 kilotons, or 100 kilotons? Turn the yield knob one way or the other."

[Ralph]

on the topic of using benzoate as burst i have used it in kno3 baced rocket fuel and it is very powerfull (seems almost to powerfull for a nozzeled rocket)and it burns quite fast i think that it could make a good burst though I haven't tried it

[dagabu]

I like straight whistle fuel (Benzoate) for breaking 3" and below, strong, can dial it in with charcoal.

[flying fish]

I've also used pure granulated whistle, but never in 3"ers. Tried it in 1-3/4" shells; the break is perfect. Throws the stars out a good ways with a nice pop. I figured a 3"er broken with pure whistle might as well be a salute...but what do I know...

[dagabu]

I've also used pure granulated whistle, but never in 3"ers. Tried it in 1-3/4" shells; the break is perfect. Throws the stars out a good ways with a nice pop. I figured a 3"er broken with pure whistle might as well be a salute...but what do I know...

 

Use around 20% charcoal and it calms right down. Not a good break for lots of metal, pops too hard and blows stars blind.

[flying fish]

Oh thanks, I must have missed that part. Do you granulate, or just use the loose powder?

[Bonny]

I like straight whistle fuel (Benzoate) for breaking 3" and below, strong, can dial it in with charcoal.

 

Are you using that as the only burst or as a booster with a BP burst? I break my 3" nicely with BP coated vermiculite and a spoonful of whistle mix (non granulated).

[lodcomm]

I made up 1lb of this mix. I proceeded as follows:

 

I cut the dextrin by 50% (which I generally do when graining my BP also)

 

I ball milled the dextrin, sodium benzoate & charcoal together with about a teaspoon of cab-o-sil for 1 hour. (I am using Phils benzoate which is small extruded "noodles" and has to be milled before using in any composition).

 

I ball milled the perchlorate (chinese anti-cake from Thunder V. or similar) by itself for 45 mins.

 

Screened the perchlorate into the mixture.

 

used a 5:1 burst:hull ratio, and coated the hulls using the shake method in 4 steps. I observed little to no clumping of the coated hulls.

 

 

Spread the mixture and sun dried for 24 hrs.

 

Ignited a small test pile of the hulls.

 

 

 

I am very pleased with the performace of this composition. It appears to release a vast amount of gas during combustion. I will be testing it out in some three inch shells shortly and will report the results.

 

Thanks everyone for the great input on this.

 

-t

Edited August 17, 2009 by lodcomm

[Mumbles]

A note I recently found out about that benzoate burst. It is designed to be used with shitty charcoal, commercial airfloat or the like. I made the mistake of using my hot willow charcoal, and have lit a grand total of about 5 stars in 4 shells. Now I don't feel so bad about blowing those spider stars blind. As is, eric said it was good for 4-5" shells, but I imagine it would work for 3" too. I dropped benzoate back a bit, and coated on cotton seed 10:9 for potential use in 6". I wanted to use it in 8", but I think it might be a bit much. Maybe I'll make a triple petal or something.