Chlorate stars

[hondo]

I have been reading that chlorate stars are easier to ignite and thougt about trying a batch, so what are the dangers? I know potassium chlorate and sulfur are a no no but why do they say to prime with meal? isnt that dangerous? and can you use meal coated rice hulls too? if its too dangerous I will keep using perchlorates

 

thanks

Edited January 12, 2009 by hondo

[WarezWally]

They are more sensitive but fine to use assuming you keep them away from sulphur, use a sulphurless prime (there are plenty out there) and burst charge.

[Miech]

The maltese prime them with meal, but the big difference is they can afford themselves some accidents. I'd go for a potassium perchlorate prime, and put a thin paper liner between the stars and burst charge. A sulfurless burst charge limits you to using H3, which is way to powerfull for anything exept 2" and 3" shells.

 

Take care when using chlorates though. Many accidents in workplaces I've heard of involved the use of chlorates.

[hondo]

Maybe I will make my comets using potassium chlorate since when I load and shoot like a single shot roman candle and I cant imagine using goex as lift would affect them when they are loaded and shot within a few minutes

[Swede]

I am still very much a novice with pyrotechnics in general, but I know a bit about chlorate, just from my masochistic amounts of research and experimentation.

 

There is no doubt perchlorate is safer in almost all regards. But I believe chlorate has gotten a bum rap, possibly because of noobs (like me) having accidents. Approached with care, and knowing the chemical and mechanical incompatibilities (such as separate tooling, screens, mill jars and media, ramming, etc) potassium chlorate could be a valuable tool in a pyro's arsenal for the prime reason that it is SO CHEAP AND EASY TO MAKE. Much more than even potassium nitrate. If you need a powerful oxidizer (your gov't has perhaps clamped down on the others) a simple cell plus table salt will yield kilos of chlorate with ease.

 

It's a kind of "self-weeding" process. If you have the technical ability to understand, conceptualize, build a cell, harvest the oxidizer, then by definition, in my book, you are smart enough to use it properly. It is the guys who buy 5 pounds off the street that are causing the accidents.

 

Remember, it was potassium chlorate that launched the color revolution in pyrotechnics. Pound for pound, it is one of the best, but it has its well-known drawbacks, hence the expensive perchlorate option. Given a choice between the two, I'd take 5 pounds of perchlorate over 15 pounds of chlorate, because I am a safety nut, and because I know now how hard it is to make (and clean up) the perc from the chlorate seed stock. But if I needed an oxidizer, and had to make my own, chlorate would be the one I'd produce, only if I lacked the ability to turn it into perchlorate. There is always the thermal decomp process in which you lose 1/3 of your chlorate, and get to experience the joys of molten potassium chlorate. NO THANKS, I'LL PASS.

 

Electricity, plus "sea water", plus the now very common MMO anode fro pool chlorinators, should allow you to make chlorate for years.

Edited January 12, 2009 by Swede

[tentacles]

Swede, you're not the only one who feels that way about chlorates - here's Mike Swisher's words on the subject -

 

"Ned, certainly having dedicated mixing sieves, and a separate place to mix chlorate-containing compositions, as distinct from those containing sulphur or antimony sulphide, is highly desirable.

 

You had mentioned in your first post to this thread a supposed hazard of mixing chlorates with sulphates. This is not entirely correct. The sulphur in sulphates is completely oxidized and there is no particular incompatibility in mixing a chlorate with a neutral sulphate such as those of strontium or barium. The exception to the rule is copper sulphate, which has a very acidic pH in solution - hence the customary name 'blue vitriol.'

 

Both sulphur and antimony sulphide sensitize potassium and barium chlorates, sulphur more so to shock and antimony sulphide to friction. These are manageable hazards - chiefly managed just by avoiding such mixtures.

 

The most disturbing hazard is that of spontaneous combustion, which was often reported during the nineteenth century when sulphur/chlorate mixtures were in widespread use. Unlike shock and friction sensitivity, spontaneous combustion is a hazard that cannot be predicted. It is hence the most frightening, because the most unmanageable potential hazard. However there were several issues at hand then which are not now.

 

The chlorates of the day were prepared using solution chemistries that typically led to impurities of potassium chloride or calcium chlorate. Traces of these compounds are known to render mixtures containing potassium chlorate less stable. According to Lancaster, some years ago the British Home Office advised firework makers to use distilled water when dampening mixtures containing chlorates. The reason for this was to avoid the formation of calcium chlorate. Shimizu notes the instability of chlorate mixtures in which potassium chloride is present. However, today's potassium chlorate is electrolytically prepared and does not contain the impurities that would have been present in nineteenth-century materials.

 

Nineteenth-century sulphur was derived from surface deposits or relatively shallow underground ones, both of volcanic origin. These contained impurities that could not be removed by liquation - e.g., iron and arsenic sulphides. The alternative was sublimation (making 'flowers of sulphur') which invariably resulted in the presence of sulphur oxides in the material, rendering it acidic in pH. This, again, contributed to instability and the occasional case of spontaneous combustion. However, today's sulphur is obtained either by the Frasch process from deep underground deposits, or as a byproduct of the desulphuring of 'sour' crude oil. Like chlorates of current manufacture, the impurities that led to problems in the nineteenth century are absent from the modern product.

 

A final consideration is the way in which star compositions were formulated 150 years ago. The typical ratio of chlorate to sulphur was about 2.5:1. Binders were not mixed with the composition. The custom was to dampen star compositions using a previously prepared solution of gum arabic in water. Those who have worked with such solutions know that they sour easily. Spontaneous combustion was not a surprising result when impure chlorates were mixed with impure sulphur and the mixtures dampened with soured gum water!

 

Today we very seldom mix chlorates with sulphur or sulphides at all. In the few cases when we do they are seldom dampened at all. This eliminates just about all the potential for spontaneous combustion.

 

I have seen advice similar to that in the Ofca book mentioned about never priming chlorate stars with black powder. I suppose if it gives one peace of mind to avoid this practice, one should by all means do so. However, I have not. The person who first taught me fireworks primed chlorate stars with homemade meal powder. He died in bed with all his fingers intact. The same was true of the man who taught him. Their combined experience in firework making went back to the 1920s. Priming chlorate stars with black powder does not bother me.

 

There is a great deal of difference between intimately mixing a chlorate with sulphur, then dampening it with sour gum water, and dusting a chlorate star with meal prime. There is simply not the intimacy of mixture nor the amount of it. If there is any danger in the process it is when the excess meal is shaken from the stars. Care should be used in this process. Gentleness in handling is necessary.

 

The only chlorate compositions I use on any scale are red, green, blue and purple colors, and silver tailed stars. The red and purple compositions contain strontium carbonate which phlegmatizes their burning and would neutralize any acidity present. The green and blue contain stearine, which is a lubricant providing physical protection against friction. The silver star uses white aluminums which are greasy in character and they fulfil the same function in that mixture.

 

Use care in handling potassium and barium chlorate mixtures and be sure to clean up well afterwards. All compositions need to be treated with respect, bearing in mind that 'safety' is a relative term in pyrotechnics. Accepting and managing risk is part of the skills of the craft.

 

If you want to eliminate risk totally from life, check into a padded cell. Someone once said that the problem with modernity is that we live without thinking about death, and then die without ever having really lived."

 

On a side note, 1003 posts! I am a post whore, it's official now. Mumbles, do I get a prize or just a good hearty slap?

Edited January 13, 2009 by tentacles

[hondo]

Yes I was only thinking about using chlorate for red, they seem the hardest to light. maybe bind with nitrocellouse laquer and meal powder?

[Swede]

Yes I was only thinking about using chlorate for red, they seem the hardest to light. maybe bind with nitrocellouse laquer and meal powder?

 

The problem with using ANY chlorate is the contamination issue. Containers, screens, racks, mill jars, everything used to produce chlorate stars should be separate from everything else. Not too many guys are willing to do that, so they avoid chlorate altogether. But it can be done if you want, just be aware of the needs (and the risks) of its use.

[PyroMan LTU]

I heard that chlorate stars shouldn't be dried In sun becouse of UV light effects chlorate and it produses ClO2 gas wich causes them spontaneous ignision. correct me If I'm wrong.

[al93535]

Chlorate does require more caution, but given the correct conditions and care its just fine to use.

 

Like it has been said, use separate mixing screens. Buy yourself a small 30 mesh kitchen sieve and use it solely for chlorate. Just keep it completely away from sulfur, and sulfides. Make the stars, dry them and prime with a perchlorate based prime. A thicker prime would be ideal as it will cushion the stars from shock and friction, as well as provide a barrier from other chemicals like sulfur. To make the star much easier to ignite you can put a light coat of meal powder, or other standard prime on the perchlorate primed star.

 

DO NOT dry them in the sun

 

DO NOT bind them with meal powder as that contains sulfur!

 

Now the stars are safer and can be used with regular break charges.

 

However the idea of using chlorate stars because they are easier to ignite seems a bit pointless to me. Because now you have to ignite a perchlorate prime. Why not just use a really hot perc prime, then a regular one to ignite perc stars?

The only advantage I see here is the cost issue, if you make the chlorate at home or can get it really cheaply.

[50AE]

Can chlorate stars be rolled ? Because of the friction inside, I wondered if it's safe.

[FREAKYDUTCHMEN]

You can even pump them So roll them wouldn't be a problem.

[Brakkie]

Just let me get this straight 50AE, Chlorate is not as evil as it's sometimes portrayed. I'm not saying there shouldn't be any extra safety issues but the thing you gotta watch out for most are contaminations. Rolling, pumping or cutting them won't create enough friction to ignite chlorate stars. Neither will Hot Glue out of a nearly smoking glue gun ignite them.

 

Chlorate stars are safe as long as you take contamination in account. Do not use any sulfur or sulfur-related compounds together with chlorate. This can and will make them sensitive.

 

In other words, you'll be perfectly fine!

[Arthur]

Start by creating a separate chlorate space! It's own everything scales scoops spatulas sieves star pumps and roller. Separate ball mill, and media. Even separate PPE gloves overalls mask etc.

 

If you can succede in being totally fanatical about separating everything connected with chlorate away from anything connected with sulphur then you can have some nice compounds.

 

I've even heard of stars wrapped in tissue paper individually to make big (50mm pro ) candles with chlorate stars and BP lift.

[50AE]

That's what I thought, but I wanted to be sure that I won't have problems. So the potassium chlorate will be my first "incompatible to others chemical". I have to isolate it nicely. Euh, can it be ball milled? If not, how it can be crushed to powder for pyro purposes in a safe way? I will make KClO3 by electrolysis and I've seen that the resulting crystals are big. Edited February 4, 2009 by 50AE

[Mumbles]

Yes, it can be ballmilled. Just use a dedicated new set of media and a dedicated jar for it.

[50AE]

I will. Gonna buy a small jar and media for chlorate milling only

[Swede]

I will. Gonna buy a small jar and media for chlorate milling only

 

Be sure to use a sharpie, and on each piece of ball mill media, write "For CHLORATE ONLY!"

 

Yes, chlorate crystals right from the cell are BIG, and that is a very good thing, as it makes separation, filtration, and cleanup of residual chlorides a snap.

[a_bab]

I've been using the chlorate for stars mainly due to the fact that it is a cheap alternative for fairly good colours (it's been said actually that the maltese stars are of te deepest colour). Just starting from the cheap sugar/KClO3 as a base, strontium carbonate gives a good red, copper chloride a nice blue, barium carbonate a *not so good* green but you get the idea.

 

The first thing is that normally, the chlorate star needs no prime. I find stupid to be worried about the posibility of accidentally igniting a wet composition that is being rolled and then worry about "what prime do I need?" It's really flame sensitive; same as the match tip composition. And it should be.

 

I never had an accident involving K chlorate thanks God, but I never had the chlorate in contact with sulphur either. Still, it makes me nervous to mix a batch of 100 g of powdered mixture of potassium chlorate/sugar. A small batch you may think, but if ignited one will get VERY nasty burns. It's much hotter than BP, it produces lots of melted potassium chloride slag (how sick is that?) and so on.

 

If you understand the risks, and STAY AWAY from sulphur, I'd say it's safe enough, much safer that barium chlorate for instance. Still, there are some (shpuld we say old?) compositions involving both sulphur and potassium chlorate. My guess is that the accidents involving it were caused due to the huge amounts manipulated (Bertholet stamp mill using potassium chlorate as a replacement for potassium nitrate anyone?).

Simply put, one can play all of his life with potassium chlorate/sulphur mxtures and die from cancer at 80. But, the 14 years old boy next street ends up in the hospital badly burned because he tried to mix potassium chlorate and sulphur. A matter of luck.

 

The risks can be managed and understood; its a question of "how much can you take"? I don't feel confortable to have sulphur around k chlorate. Others mix the chlorate with red posphorus and claim it's "safe enough".

Got the difference?

[PyroMan LTU]

Hey, I was thinking of making some blue chlorate/sugar stars, but J Conkling states that chlorate and copper oxide (CuO) when present in moisture can react and produce copepr chlorate which is a very unstable and violent material. Is it possible that this reaction may accure in practice?

[50AE]

How would copper chlorate form when copper oxide is insoluble (or almost) ?

[PyroMan LTU]

yeah, I also thought of that... Well since it was discussed in the book, I just wanted to make sure...

[Ralph]

CuO would be fine but another commonly used copper source copper oxychloride is not suitable as it is partially soluble and could end up causing the creation of copper chlorate

[Mumbles]

Copper salts sensitize chlorate mixtures. This is a well known fact. It only takes minute amount of copper chlorate to accomplish this. There are such things as solid phase reactions, just FYI.

[50AE]

Do they occur immediately at a dangerous level, or with time when the comp is stored ?