17 replies to this topic

[Potassium chlorate]

One of the eternal debates in pyrotechnics is the one concerning the best blue. Paris Green formulas and New Blue are very strong candidates, but many people have praised less toxic, cheaper and easier-to-get-hold-of copper compounds. In Fireworks like Granddad used to make them there are some formulae that would be of interest even today, at least with some minor changes.

This for instance:

potassium chlorate 46
calomel 23
copper sulfide 23
schellack 6
copper oxychloride 2

or:

potassium chlorate 47
calomel 6
copper sulfide 19
copper oxychloride 6
sulfur 19

What about substituting potassium perchlorate for potassium chlorate and ammonium perchlorate for calomel and red gum for shellac in the above formulae? Wouldn't that be interesting?

[Arthur Brown]

With Mercurous chloride as the chlorine donor I wouldn't want to bother with the formula, in fact the only ingredient the I don't have an issue with is the shellac -a pretty usual fuel/binder when used with alcohol. Chlorates vs Copper salts have complications and chlorates with sulphur aren't nice either.

[Potassium chlorate]

Like I said: you could do substitutions. KP instead of KK and AP instead of calomel.

From what I've read, it's a common misunderstanding that potassium chlorate and copper don't go well together. Someone (a well-known pyrotechnician I think) once mixed copper sulfate with potassium chlorate, and it ended up with an explosion, though it was more likely the sulfur in the sulfate that was to blame than the copper.

[Arthur Brown]

As the calomel is a chlorine donor, I'd look to using parlon PVC or Saran, or more esoterically HCE. Then the first formula could be a good experiment.

[dr thrust]

agreed calomel would be pants with only a 15% chlorine content, as apposed to parlon with a 65-70% chlorine content, so the parlon wins hands down
""What about substituting potassium perchlorate for potassium chlorate and ammonium perchlorate for calomel and red gum for shellac in the aboveformulae? Wouldn't that be interesting""
as you know , nice blues are all about a cool flame temp so again the chlorate used in the old formula would be favorable with its low melting point of 356 0c, and the perchlorate having a not successful 525 0c, ever tried the famous conking blue with its 65% perc content ? a really washed out blue in my opinion

Edited by dr thrust, 30 April 2011 - 11:10 PM.

[Mumbles]

You can make perfectly acceptable blues with potassium perchlorate. Those that favor chlorates will probably disagree of course. In two side by side tests done here in the States, a perchlorate blue won hands down both times, over even the old chlorate/HCB/Paris Green formulas. Perchlorate blues tend to look kind of washed out to me up close (evidence of a higher temp), but in the air at appropriate distances is the only way to really evaluate them.

I agree with the replacing the calomel with a more conventional chlorine donor. When using perchlorates, an axillary chlorine source is usually needed. With all the sulfur you never know though. Try them out, and let us know. I've heard good things about copper sulfide.

Edited by Mumbles, 01 May 2011 - 05:19 AM.

[Arthur Brown]

One of the nicer blues I've seen was based on the Phiko blue. KPerc, hexamine, copper oxide, parlon, plus a bit of binder. The only better blue was a similar formula but with NH4Perc. IMO Nothing justifies the inclusion of Calomel (the mercury must go somewhere) and likewise Paris Green. Chlorates also have their share of problems so are best not used. In this case progress has been forward to maintain or improve the effect while reducing the hazardous chemicals.

Fireworks get a bad enough press without us putting known severe poisons up into the sky.

[MDH]

Chlorate (PyroSwede?),

What is it exactly that fascinates you about these older formulas? Do you believe the effect is different enough to have a remarkable quality compared to the mostly KP blues we use now, or perhaps even superior?

I have tried a composition from one of these old books containing potassium chlorate, ammonium chloride, copper sulfide and paraffin with very similar portions to those in this bizarre old book...

Was it blue? Yes. Did it have a unique, special blue that I prize? Not really, and the burning properties were mediocre. Though if I remember correctly an AFN contributer in did at some point mention calomel had a unique luminosity and I haven't really tried that. Otherwise I think we are already on the right track with the chemicals we already have available.

If you'd like to see old-style formulas containing sulfur as fuels (Which, for reasons that are pretty well known here, intensifies colors), paris green, copper-ammonium compounds, sal ammoniac and other old ingredients, I'd highly recommend browsing Russian pyrotechnics forums. I have a post containing the links to many of those forums on this thread.

Good luck on your adventures.

[Potassium chlorate]

Chlorate (PyroSwede?),

What is it exactly that fascinates you about these older formulas? Do you believe the effect is different enough to have a remarkable quality compared to the mostly KP blues we use now, or perhaps even superior?

I have tried a composition from one of these old books containing potassium chlorate, ammonium chloride, copper sulfide and paraffin with very similar portions to those in this bizarre old book...

Was it blue? Yes. Did it have a unique, special blue that I prize? Not really, and the burning properties were mediocre. Though if I remember correctly an AFN contributer in did at some point mention calomel had a unique luminosity and I haven't really tried that. Otherwise I think we are already on the right track with the chemicals we already have available.

If you'd like to see old-style formulas containing sulfur as fuels (Which, for reasons that are pretty well known here, intensifies colors), paris green, copper-ammonium compounds, sal ammoniac and other old ingredients, I'd highly recommend browsing Russian pyrotechnics forums. I have a post containing the links to many of those forums on this thread.

Good luck on your adventures.

Yes, a.k.a. Pyroswede.

My "theory" in some cases is that some of the older, now banned or at least abandoned, chemicals might have been better. Even though modern formulae are scientifically based in a quite different respect, some older formulas might still be superior but not politically correct from the environmental point of view.

[Potassium chlorate]

One of the nicer blues I've seen was based on the Phiko blue. KPerc, hexamine, copper oxide, parlon, plus a bit of binder. The only better blue was a similar formula but with NH4Perc. IMO Nothing justifies the inclusion of Calomel (the mercury must go somewhere) and likewise Paris Green. Chlorates also have their share of problems so are best not used. In this case progress has been forward to maintain or improve the effect while reducing the hazardous chemicals.

Fireworks get a bad enough press without us putting known severe poisons up into the sky.

Do you happen to know the exact formulation for Pihko AP#1 and #4? Pyroguide has them but they don't equal 100%.

[Mumbles]

Did it ever occur to you that they're not in percentages, but rather parts? Petri Pihko posted these formulas originally on rec.pyro. As you will see, he changes his mind from time to time, yet they're clearly given in parts, not percents.

Original Pihko #4 http://groups.google...5e74cc9f612e228

Something that is neither #1 nor #4: http://groups.google...19036920cfe2fda

Another iteration, which has something more resembling what I have as Pihko #1: http://groups.google...n&&q=Pihko blue

[Potassium chlorate]

Yes, I thought about it but didn't see the reason why someone should have it in parts so close to 100, so I thought it was a mistake from the one posting it on the page, but thank you.

The interesting thing is the low content of AP in all of them, a bit like the low KP content in Chinese Blue#1. AP is expensive anywhere you buy it, if you can't but it from China in quantities of a ton or so. Sulfur and copper(II)oxide on the other hand are extremely cheap for the most part.

Edited by Potassium chlorate, 05 May 2011 - 12:50 PM.

[Mumbles]

For me AP is comparable with the price of copper oxide. A benefit of surplus from the military and space industry I suppose. With the price of copper, AP and CuO may not much longer be all that different in price even in Europe.

The deep blue microstar formula appears to use CuO as a secondary oxidizer perhaps. I don't find the AP content all that low in the Pihko formulas. Perhaps if the comparison is "new blue" or whatever the copper benzoate formula is called. I believe that formula is stoichiometric, where as these others probably have an oxygen negative balance, and perhaps not quite as good of fuel values as pure benzoates.

[Potassium chlorate]

New Blue is great but very expensive: 82% AP. Copper benzoate isn't very cheap either.

The cheapest AP I can find in Europe is about US$35/kilo. Though I see that copper oxide isn't much cheaper anymore. US$23/kilo.

I'd prefer a chlorate based blue, though. Paris Green is as good as impossible to get hold of. I got a small sample, but the quality seemed to be poor. I couldn't see a very superior colour in that (Lancaster Blue pill box#1). Maybe copper acetate would perform almost as good as Paris Green with some help from CuO.

[Potassium chlorate]

I just made 10 grams of Hardt Blue Star #4:

Potassium chlorate 62
Cupper(II)oxide 13
Red gum 9
Parlon 11
Dextrin 5

As a loose powder it burns a bit light-blueish but I made a pumped test star of it and got some small moist lumps over. Those lumps burned slowly with a very deep blue colour. Maybe if you use shellac instead of read gum you will get the stars to burn deeper as well.