22 replies to this topic

[50AE]

This summer, I'm resuming my pyro activity and I'm nervous to find out the best chlorate compositions. I'm also nervous about safety, so I want safe compositions. But you may wonder why I want to use "chlorate" as oxidizer ?

The main reason it's - it's very cheap and easy to get ! I'm preparing it by the electrolysis of KCl solution. I recrystallize it two times and I obtain a good quality chlorate.
But as you know, it has incompatibilities ! No sulfur, no metal powders, and many others. As safety reference, I'd like to use Bill Ofca's article about chlorates.

So my requirements are :
1. Safety at first place
2. Good color/effect at second place
3. Simplicity at third place.

The chemicals for colored stars I have are :
Oxidizers : barium nitrate, strontium nitrate, cupric oxide*, sodium nitrate, potassium perchlorate*
Fuels : red gum, parlon, shellac, PVC, charcoal

*cupric oxide (metal oxides) is not recommended to be added to chlorate compositions, by Bill Ofca
*I don't have much potassium perchlorate and it's very hard to find, I'd like to use as little as possible.

The chemicals for colored stars that I'll try to get :
Fuels : barium carbonate, strontium carbonate, copper oxychloride (Paris green - I can't !)


Note that I'm also able to make barium chlorate.
Also note that next week I'm buying a passfire account, for now I have a guest one.

Thanks ahead !

[maxman]

Hi and welcome to the forum. There is a wealth of info on here if you search and some very experienced people to back it up.

Barium chlorate will make some of the best green's and make ideal roman candle stars as they ignite easily, give a great green and have a large flame so look big in the sky However!!!! Did you know that Barium chlorate is very unstable and has caused many accidents in history?! Green chlorate stars can and do spontaneously ignite! Not something I'd want hanging around in my house.

I'll say this before someone else does. Fantastic effects can be made from the three main ingredients of gunpowder. Have you seen tiger tail stars? add a little aluminium powder and make streamers, a bit of sodium bicarbonate from the supermarket and you've got glitter too.

I wish you well in your pyro activities, but I think you'll find that the general consensus it to stay well away from chlorates or you activities could be very short lived!

Good luck and stay safe.

Maxman

[50AE]

Hi and welcome to the forum. There is a wealth of info on here if you search and some very experienced people to back it up.

Barium chlorate will make some of the best green's and make ideal roman candle stars as they ignite easily, give a great green and have a large flame so look big in the sky However!!!! Did you know that Barium chlorate is very unstable and has caused many accidents in history?! Green chlorate stars can and do spontaneously ignite! Not something I'd want hanging around in my house.

I'll say this before someone else does. Fantastic effects can be made from the three main ingredients of gunpowder. Have you seen tiger tail stars? add a little aluminium powder and make streamers, a bit of sodium bicarbonate from the supermarket and you've got glitter too.

I wish you well in your pyro activities, but I think you'll find that the general consensus it to stay well away from chlorates or you activities could be very short lived!

Good luck and stay safe.



Maxman

Thanks

Well, of course I know that chlorates have done incidents before. And maybe you know that in the past, many "unsafe" compositions were used. Chlorates were mixed with Sb2S3, realgar, sulfur... Chlorate stars were primed with black powder... Chlorate burst charge was used with sulfur containing stars and etc...
What I know also, is that today the Maltese continue to use these dangerous combinations, which results in an "incident" per year.

I cannot aggree that all chlorate mixtures are so evil. H3 for example, is proven to be weakly sensitive to shock and friction. So why should a star composition containing barium chlorate and shellac be so dangerous.
I can't see a problem, after I've done isolating my working area from incompatibilities and static electricity.

I want to let you know that I'm not a beginner, I've read many info about chlorates and I know its properties. And if I missed something, I'll gladly read it as well.

I've made stars from the free components of gun powder and I can't deny, they're beautiful ! Glitters, flitters, strobes, spider stars, tigertails...I prefer them than most of the colored star compositions that exist But I'd want some color too, it's not useless to make some different stars.

[Arthur Brown]

I bought a copy of Weingart, though it's an old text you may find it useful as most mixes he makes are chlorate or nitrate based, though perc still features in some.

Alternatively get some of Swede's MMO electrodes and go for NaClO3 then get some Pt electrodes to go through to perc, Only then can you exchange the cation for K.

[50AE]

I got my anodes from Swede to make chlorate, but the synthesis of perchlorate seems to be very complicated. Platinium is expensive, alternatively I don't have the chemicals and lab materials to make PbO2 anodes. Let's say that I've made some perchlorates, that are impure. Next, I have to purify them from chlorates. I really don't have many tools and money to do this. Maybe I will, in the future.

So why bothering preparing perchlorates, when chlorates are simpler and give off a better color ?

Some of my friends had a copied .pdf of Weingart, I'll ask him and check it out.

[Creepin_pyro]

I haven't done much with chlorates, but this is a great formula from John Rielly:

This is a very nice chlorate "violet purple" Giovanni Forli sent me
some time ago and I like it a lot:

Potassium Chlorate 1 kilogram
Black Copper Oxide 220 gms.
PVC (very fine dust) 160 gms.
Strontium Carbonate 160 gms.
Red Gum 100 gms.
Gum Arabic 60 gms.

Damp with water and cut or roll. Makes a fast burning, easily lit
star. I prime lighly with fine meal. If you use Parlon instead of
PVC, it may change the color and burn slightly. Also, this is more on
the blue side of "purple" than the red. Hardt also has some very good
compositions for purple using chlorate as well as perchlorate.

Passfire has a boat load of chlorate comps so you should have all you need when you get your membership. Baechle's pyrocolor harmony also has some interesting comps, but alot are older and contain sulphur. I did do a very small scale test of a scarlet red which was absolutely beautiful, but Iwouldn't recommend it from a safety point of view.

If you're going to make any Barium Chlorate, I would recommend making some aqua stars with it.

Please do stay green : )

[50AE]

Thank you ! I wonder though If i can replace the gum arabic with another binder ? Dextrin, or adding more red gum ?

[Creepin_pyro]

When I tried it I used dextrin - 5% IIRC. Worked fine. Alternatively, you could probably omit the gum arabic and just bind with alcohol, but it is likely to get very sticky.

[Arthur Brown]

There must be a system of Chlorate compatible mixes somewhere without all the incompatibilities. Perhaps it's time to have a chlorate formulary.

I note that above someone has primed a chlorate star with meal that's a chlorate sulphur mix straight away.

Chlorate stars need H3 for break and the fuse needs to be sealed against sulphur leaching out of the BP based compound into the H3 -should be easy with NC lacquer but should be done.

Most of the old formulae were developed without the present wisdom about incompatibilities.

[50AE]

I note that above someone has primed a chlorate star with meal that's a chlorate sulphur mix straight away.

Chlorate stars need H3 for break and the fuse needs to be sealed against sulphur leaching out of the BP based compound into the H3 -should be easy with NC lacquer but should be done.

Most of the chlorate star mixtures are easy to ignite, so they wouldn't need prime. But I heard somewhere that priming them with sulfurless meal will increase their stability to friction.

I plan using chlorate stars on small shells (2 and 3"). I don't have visco, so I'll be using a spolette with sulfurless BP. For the smaller than 3" shells, I will of course isolate my visco.

[pyromaniac303]

Unfortunately it seems most of the blue/purple chlorate comps have copper oxide in them. I have done friction and impact tests on one of these and I couldn't get it to ignite, though that does not mean it is safe though, just helped to reassure me it was OK to make.

I think that copper salts have a catalytic effect and speed up the burn rate of chlorate mixes, so even stars with relatively low oxidiser content will burn fast and brightly.

I have spoken to several people who prime chlorate stars using ordinary meal and it seems to be normal practice in some countries, though I wouldn't do it personally.

I prime all my chlorate stars with sulfurless meal +10% silicon (run bentonite or KNO3 through your mill jar after washing to ensure all sulfur is removed before milling the sulfurless meal). Although I'm sure the silicon isn't needed with most stars, it is nice to have a jar of universal prime that you know is safe on all chlorate stars, and will ignite anything. This also enables me to use any burst I like without worrying about incompatibilities, provided that the layer of prime on the stars is above 1mm thick, and will not crumble when dropped from a few feet in the air.

Remember that starch based fuels sensitize chlorate mixtures also, things such as sucrose, glucose, possibly dextrin, has anyone tested this? Also compositions with higher acidity are far more sensitive, therefore gum arabic is not the best binder for chlorates because solutions of gum arabic turn acidic over time.

Edited by pyromaniac303, 23 May 2009 - 03:38 PM.

[50AE]

I have also wondered if replacing the perchlorate with chlorate in some compositions with compatible reagents will work fine ?

[digger]

.

Edited by digger, 25 May 2009 - 08:09 AM.

[pyrotrev]

PS shouldn't this be in the Pyrotechnic Formulas section?

[Mumbles]

You know, sometimes I wonder if you guys have any practical experience with these warnings you're giving, or are just regurgitating stuff you've read. Most of them are over exagerated, and founded in accidents that happened well before most, if not all, of you were born. Sulfur causes issues when it contains residual acidity, primarily when purified by sublimation. With the quality of sulfur available now, it's almost completely devoid of acid. Chlorate and sulfur is only marginally more impact sensitive than perchlorate and sulfur(less than a 3% difference IIRC). That is with an intimate mix too.

All fuels are going to be sensitizers for chlorate, and every oxidizer. Charcoal is a sensitizer for KNO3, I guess you guys have to stop using BP, and every charcoal streamer. Copper oxide speeds up the burn rate of chlorates and perchlorates alike. Most transition metals do actually. There was some concern raised elsewhere with the formation of copper chlorate, but that stuff is so insanely hygroscopic it'd never do anything.

Granted, I try to avoid the mixture of chlorate and sulfur like most should out of the legend more than anything really. I would certainly do it in a commercial setting too, but we're not professionals here. However your shell is not going to set off a nuclear reaction if the stars are primed with BP, or broke with BP assuming you don't have shit chemicals. Neither will having a BP based fuse. About the only "downside" is that your shell will go off almost every time if the fuse fails to light and strikes the ground, if you can even call that a downside. I'd rather have a shell go off on the ground than have some kid find it.

Edited by Mumbles, 07 June 2009 - 04:05 PM.