Another "Blue Star" Topic

[cmjlab]

What are your favorite KCLO4 or KCL03 Blue Star formulas?

 

I've read many of the threads on here, and tried many of the formulas like: Pyro Science Blue, Hardt's #6 Sulfur Blue, Shimizu B49, B70 Blue, Ofcas Lactose and Phenolic Blues, all the way too making Copper Benzoate and trying Blesser's Benzoate Blue.

 

So far the AP Benzoate Blue was by far the best, but a pain to make, and I'd prefer to stay away from AP because I like KCL03 formulas for wind critical velocity.

 

For the non-AP blues, I actually found the Sulfur Blue to be best for color but too pale to use with any other vibrant colors. The ones like Velines (and others with metal) were horrible for my purposes (no offense).

 

Anyone else have a decent blue worth a try? (Yes I get it - beauty is in the eye of the beholder!)

 

Thanks - Charles

[Crazy Swede]

Blue will always be the weakest colour since there is no way to change the physics and chemistry behind the emission.

 

Many ordinary formulas can be used successfully if all ingredients have high purity AND if the stars are made and combined wisely with other effects.

 

There is no Holy Grail blue formula!

 

Trust me, I have been searching for 40 years!

[a_bab]

You can get a dark blue but it won't put lots of light. Copper benzoate blue is one of these as you noticed.

The eyes are not sensitive to blue. You can see this looking at Xmas lights from distance: blue is always dim compared to red or green.

[cmjlab]

Thanks for the replies - you bring up a good point for the "purity" of chemicals. If I had to pick a chemical that is likely not as pure as it could be, it'd probably be my KCLO4 (based on how nicely free flowing it is, and compared to the Chinese "HP" chunkiness in the past).

 

Has anyone expirimented with a real High Purity (99.9%) KCLO4 like Swedish or I believe it was Taiwanese that I've read are the purest (next to another APC Forum user who makes his own high purity)? Or is there no such thing anymore? If there is really pure KCLO4, has anyone observed a noticeable difference?

 

I guess it probably is a moot point, as it's not available to me, and I don't have the patience/time/money to make my own.

 

Also - has anyone tried a Copper Acetoarsenate / KCL03 formula? That's one of the chemicals I've not found, but have read Shimizu's instructions on making small amounts of it. If it'd be worth it, I'd potentially attempt to make some. (There is a thread on FW.com about synthesizing some with a couple simple suggestions to improve the purity of the yield).

 

I'm not ready to give up yet though, so i also reiterate - what are other people's favorite formulas?

Edited December 11, 2022 by cmjlab

[Arthur]

60 Potassium Perchlorate,

10 Parlon,

10 Copper(II)Oxide,

10 Red Gum,

10 Dextrin

 

Was a well regarded blue at a comp I attended. However it's almost like Pihko Blue and Pyro Science blue.

The important detail with blue comps is to make it burn with lots of gas to keep the flame cool. IF you are wise and comfortable dealing with Ammonium Perchlorate then this oxidiser makes more gas so the flame burns cooler so the blues are better. BUT read up on AP first learn and deal with the incompatibilities first.

[cmjlab]

Thanks Arthur, I am using a Blue similar to that, using Phenolic Resin instead of Red Gum - I agree it is a good blue.

[Zumber]

How about this.

Kclo3- 5500

Black cupric oxide- 2500

Pvc- 750

Pvdc- 250 or just pvc (1000)

Shellac about 200+ mesh finer-500

Dextrin white-100

It was developed by me long time ago but now a days I didnt tried.

In my experience Though I have acess to parlon and red gum, during testing blue formulas I observed using parlon and red gum gives nasty flame and blue colour washed.....shellac and pvc powder worked very good for me.

Edited December 12, 2022 by swapnilsutar1988

[cmjlab]

Thank you for the comp, I will give it a try later today. I agree with you on the red gum and have moved away from it almost entirely. I mainly use KCLO4/Phenolic Resin or KCL03/Shellac now and have seen quite the improvement from eliminating the red tinge.

[JAWChemist]

Blue will always be the weakest colour since there is no way to change the physics and chemistry behind the emission.

 

Many ordinary formulas can be used successfully if all ingredients have high purity AND if the stars are made and combined wisely with other effects.

 

There is no Holy Grail blue formula!

 

Trust me, I have been searching for 40 years!

I am interested in any comments based on your experience. Do you have any interest in a deeper discussion about your work to create a blue pyrotechnic?

[Crazy Swede]

@JAW,

My experience is not that interesting. My best blues were small slag forming stars. Very deep blue but also very dim. The were nice in smaller effects at closer range.

 

The idea with the slag formation was to keep the flame as free as possible from particles. Each star formed one piece of slag almost as big as the original star. Ill look for the formula tomorrow.

 

Have you read the work by Dominykas Juknevelicius?

Strongly recommended!

[JAWChemist]

@JAW,

My experience is not that interesting. My best blues were small slag forming stars. Very deep blue but also very dim. The were nice in smaller effects at closer range.

 

The idea with the slag formation was to keep the flame as free as possible from particles. Each star formed one piece of slag almost as big as the original star. Ill look for the formula tomorrow.

 

Have you read the work by Dominykas Juknevelicius?

Strongly recommended!

I almost missed your reply. It is not clear how the forum alerts members to a response. I forgot my reply was in APC and had to track it down.

 

I like the approach of developing a concept and attacking the problem based on the concept. Thank you in advance for looking for the formula.

 

I have reviewed some of Juknelevicius work but far too lightly. The earliest download date (1/9/2022) for the file I have on my computer is Juknelevicius, Klapotke, et. al.'s "An Experimental Comparison of Selected Blue Flame Pyrotechnics" and the most recent (12/3/22) is his PhD. dissertation from Vilnius U (2020).

 

I agree that dark blue on a black sky would be challenging under the best of circumstances.

 

My issue is that I have far too limited experience in the field so the concepts under consideration may be well tread ground as well as an unsuitable location for compounding and testing. All of which will have to be resolved.

[Crazy Swede]

I almost missed your reply...

 

...I have reviewed some of Juknelevicius work but far too lightly. The earliest download date (1/9/2022) for the file I have on my computer is Juknelevicius, Klapotke, et. al.'s "An Experimental Comparison of Selected Blue Flame Pyrotechnics" and the most recent (12/3/22) is his PhD. dissertation from Vilnius U (2020)...

I hope you find my respons more easily this time. :-)

 

The "An experimental comparison of selected blue flames" article by Juknelevicius and Hahma is probably one of the most important texts ever about blue flame production. I just wish they would have incorporated the "Sulfur Blue" formula from the Hardt book (No. 6 in table 15-10 on page 148) since that one often is considered as one of the best. Dechlorane needs to be substituted for other more easily found chlorine donor though.

 

Arno Hahma really knows his stuff and Petri Pihko (creator of "Pihko Blue") learned a lot from him. I met them both a couple of times and was impressed about their approach to formula development:

 

1. Decide general amounts of oxidants and colour imparters by experience and gut feeling.

2. Calculate the amount of chlorine donor needed to form the monochloride in question, with a great excess of chlorine!

3. Calculate how much oxygen that is available.

4. Add additional fuels if necessary and adjust the amount of oxidant so all fuels containing carbon creates carbon monoxide (not carbon dioxide!)

5. If needed, adjust to 100 %

 

Regarding my own best blue formula, the one forming a lot of slag, I think it was about like this:

 

40 % potassium perchlorate

14 % black copper oxide

15 % lactose

5 % fine magnalium

10 % guanidinium nitrate

16 % chlorinated rubber

 

Moistened with +15 % of a 50/50 mix of acetone and butyl acetate and cut to small stars, almost micro stars.

 

But I saw a note saying it changed to bluish white at the end of the combustion so the amount of guanidinium nitrate should be increased. Cannot remember if that fixed it though?

Edited December 15, 2022 by Crazy Swede

[cmjlab]

Just to follow up with what I went with for my "go-to" blue star...

 

 

I found "Agten Blue" on fireworks cookbook.com, and tried that formula. It's definitely a decent / bright / fast burning / easy ignition / clean burning blue star!

 

My only regret is when I made 2k of the stars, I wish I cut them a bit larger because they burn pretty fast.

 

https://youtube.com/shorts/LUx9NU54MBU?feature=share

[cmjlab]

Deleted - I was trying to embed the video. It didn't work. Edited December 22, 2022 by cmjlab

[Arthur]

Copper salts have flame colours from green to blue and mixed colours. In a flame (where every improbable species exists transiently) copper chloride species emit blue, copper hydroxy (-OH ) species emit green. The problem for us is that the blues are swamped by the greens and that pure blue spectral emission is either missing or masked by the green.

 

Maybe there is no cheap and easy blue that works with commercial grade chemicals. As a pure guess, the good blues are expensive and maybe contain chemicals that are too expensive for the retail market. The military manage good blues, which may be expensive or.... Remember that most firework comps are made for mixes of cheapness and effectiveness. If a factory makes a cheap blue firework at a price, would a really good blue firework of the same size and effect sell for 5 or 10 times the price? I think not! BUT for competition I suspect an expensive blue could be viable.

 

Be very careful assigning a country of origin to perc. I once saw a big (25kilo) bag of "Spanish" perc with the bag printed in Spanish and English, however the inner bag was printed with Chinese characters so this expensive perc wasn't made in Spain but was made in China like all the cheaper alternatives. I suspect that the whole world's perc is made in China, and shipped under different labels. Likewise don't assume that perc is pure, it's "useful" but i doubt anyone in the world can give a real purity figure for it, for every batch or bag. It's NOT a high purity pharmaceutical of high value and risk, it's probably only used in cheap disposable fireworks.

As a comparison, There was some agricultural potassium nitrate being sold, BUT when a magnet was passed over it small bits of wire were recovered, Clearly a sieve had failed in the manufacture. For agriculture it was insignificant, but as a high purity chemical it was a failure. Of course it worked for pyro, but it certainly wasn't optimum without magnet fishing.

[JAWChemist]

I hope you find my respons more easily this time. :-)

 

The "An experimental comparison of selected blue flames" article by Juknelevicius and Hahma is probably one of the most important texts ever about blue flame production. I just wish they would have incorporated the "Sulfur Blue" formula from the Hardt book (No. 6 in table 15-10 on page 148) since that one often is considered as one of the best. Dechlorane needs to be substituted for other more easily found chlorine donor though.

 

Arno Hahma really knows his stuff and Petri Pihko (creator of "Pihko Blue") learned a lot from him. I met them both a couple of times and was impressed about their approach to formula development:

 

1. Decide general amounts of oxidants and colour imparters by experience and gut feeling.

2. Calculate the amount of chlorine donor needed to form the monochloride in question, with a great excess of chlorine!

3. Calculate how much oxygen that is available.

4. Add additional fuels if necessary and adjust the amount of oxidant so all fuels containing carbon creates carbon monoxide (not carbon dioxide!)

5. If needed, adjust to 100 %

 

Regarding my own best blue formula, the one forming a lot of slag, I think it was about like this:

 

40 % potassium perchlorate

14 % black copper oxide

15 % lactose

5 % fine magnalium

10 % guanidinium nitrate

16 % chlorinated rubber

 

Moistened with +15 % of a 50/50 mix of acetone and butyl acetate and cut to small stars, almost micro stars.

 

But I saw a note saying it changed to bluish white at the end of the combustion so the amount of guanidinium nitrate should be increased. Cannot remember if that fixed it though?

Hi Crazy Swede

The APC forum in Discord chat email alerts me. I have turned on "Follow this topic" so I am less likely to miss comments.

 

There are several topics but I'll save some of them till later after the holidays.

 

Item 1.

This is interesting and goes to the reason for joining the forum. My background is a formulator for metalworking fluids where I have both the expertise in the science of designing experimental mixture blends (DoE of Mixtures) and formulation chemistry of the component. For pyrotechnics, collaboration with someone that is less lacking in practical experience would be beneficial. Part of the delay in remembering to look for a reply was that I am converting a computer program written several decades ago to calculate blend mixtures for selection. It was limited by the total number of blends it could handle and that has had me sidetracked.

 

Item 2 and chlorinated rubber

What is your experience/opinion (safety/usefulness/stability) on using ammonium chloride in a formulation as a chlorine donor?

I have familiarity with chlorinated paraffins as they are used in metalworking. Using them as chlorine donors bring up the issues that these are used in compounding firemen's boots, don't burn well, leave a hard char when doing a flash point (they don't have one) that would necessitate a higher temperature which is bad (decomposed CuCl) and carbon tetrachloride (a low molecular weight analog) was used to in fire extinguishers. To release the chlorine, the material would have to be oxidized and chlorine should win over oxygen or the material has to be vapor ionized and CuCl destroyed. The discussion of chlorinated organic would suggest them as poor sources for HCl.

Chlorine would be available if the metals (Mg,Al) are used and make refractory oxides but then you have a high temperature and incandescent particles to wash out the blue light.

Considering the inorganic alternates used (mercury chloride and lead chloride) are acidic salts and would make HCl available to copper to make copper chloride. The most ridiculous extreme would be arsenic chloride but it has the issues of toxicity, being a liquid (frowned upon by regulations) and reacts with water. It is only mentioned as an example of how inorganic would make a great source of HCl like other inorganic chlorides.

Ammonium chloride would be a source for HCl but what I have seen suggest there are some stability issues with this (reacts with nitrates to make a slightly hydroscopic ammonium nitrate, tend to vaporize before being usable). One would expect ammonium perchlorate, which is used a lot, to have similar acidic issues as ammonium chloride. The nitrate can be an explosive. My only professional pyrotechnic works was on an inverter emulsifier to make a blasting emulsion. The ammonium chlorate seems to be far too unstable either as a component or occurring due to any instability reactions. It as used in the 18th century but replace by safer one. If this was due to the use of chlorate, it might be reconsider. It is also slightly hydroscopic. Most of the formulas give in https://pyrodata.com/chemicals/Ammonium-chloride all seem to have chlorate. https://www.skylighter.com/blogs/fireworks-information/chlorine-donor-chemicals notes its use but suggest it vaporizes out too easily.

I am looking at other chlorine donors. The current design has ammonium chloride as 1 of the 20 some components in it and the number has to be decreased because of excess computation time.

 

Item Hardt Blue #6

This is high in sulfur and uses potassium perchlorate. Sulfur (acid forming) seems to be an issue with chlorates. Is the stability issue with perchlorate and sulfur that much better? Do you have any information on the same formula with ammonium perchlorate other than thePihko BSP #4?

 

Mark Twin, “Sorry for the long letter but I don’t have time to write you a short one.”

Copper salts have flame colours from green to blue and mixed colours. In a flame (where every improbable species exists transiently) copper chloride species emit blue, copper hydroxy (-OH ) species emit green. The problem for us is that the blues are swamped by the greens and that pure blue spectral emission is either missing or masked by the green.

 

Maybe there is no cheap and easy blue that works with commercial grade chemicals. As a pure guess, the good blues are expensive and maybe contain chemicals that are too expensive for the retail market. The military manage good blues, which may be expensive or.... Remember that most firework comps are made for mixes of cheapness and effectiveness. If a factory makes a cheap blue firework at a price, would a really good blue firework of the same size and effect sell for 5 or 10 times the price? I think not! BUT for competition I suspect an expensive blue could be viable.

 

Be very careful assigning a country of origin to perc. I once saw a big (25kilo) bag of "Spanish" perc with the bag printed in Spanish and English, however the inner bag was printed with Chinese characters so this expensive perc wasn't made in Spain but was made in China like all the cheaper alternatives. I suspect that the whole world's perc is made in China, and shipped under different labels. Likewise don't assume that perc is pure, it's "useful" but i doubt anyone in the world can give a real purity figure for it, for every batch or bag. It's NOT a high purity pharmaceutical of high value and risk, it's probably only used in cheap disposable fireworks.

As a comparison, There was some agricultural potassium nitrate being sold, BUT when a magnet was passed over it small bits of wire were recovered, Clearly a sieve had failed in the manufacture. For agriculture it was insignificant, but as a high purity chemical it was a failure. Of course it worked for pyro, but it certainly wasn't optimum without magnet fishing.

Hi Arthur

Since you mentioned the emission spectra, one for copper chloride is available in the open literature. Formulas based on copper acetoarsenate (Paris Green) are often mentioned as a reference for blue color but I have not been able to find an emission spectra. Have you ever seen one? It is of interest because some of the formulas with this do not seem to contain a chlorine donor and it would be of interest to compare them for directional ideas. The alternative is to go research the local university library for reference not in the open literature.

[Richtee]

 

 

Mark Twin, “Sorry for the long letter but I don’t have time to write you a short one.”

 

LOL... Love me some Twain... and blues are a bitch. Wait..perhaps a mistress?

 

My best...

Edited December 25, 2022 by Richtee

[Crazy Swede]

When it comes to chlorine donors ammonium chloride is seldom effective since it sublimes so easily and it seems like very little splits up into available chlorine.

 

The sublimination itself steals energy from the combustion zone so ammonium chloride tends to heavily slow down the burn rate.

 

Ammonium chloride is incompatible with magnesium and difficult with magnalium due to corrosion.

 

Chlorinated waxes, and polychlorinated or polybromated, organics used for anti-flame purposes, tend to be excellent chlorine donors in pyrotechnics but many have been banned today for environmental reasons.

 

Chlorinated rubber is ok but should be ball milled and not used at too high concentrations sine it often creates a short slag tail that can disturb the aesthetics.

 

Saran resin (PVDC) is very god but gets harder to find nowadays and is always sold as a co-polymer so the amount of chlorine can be uncertain.

Edited December 25, 2022 by Crazy Swede

[Crazy Swede]

Regarding the emission spectra from traditional chlorate/Paris green compositions Im sure they would not differ much from other blue compositions.

 

The emitter is always CuCl* (unless the formula is based on bromine) and as far as I understand potassium chlorate will act like a chlorine donor in those cases.

 

I do not understand the mechanism but something (arsenic and/or sulphur, depending on the formula) must scavenge the potassium so the chlorine becomes available for the copper.

[kingkama]

Regarding the emission spectra from traditional chlorate/Paris green compositions Im sure they would not differ much from other blue compositions.

 

The emitter is always CuCl* (unless the formula is based on bromine) and as far as I understand potassium chlorate will act like a chlorine donor in those cases.

 

I do not understand the mechanism but something (arsenic and/or sulphur, depending on the formula) must scavenge the potassium so the chlorine becomes available for the copper.

Paris green blue is a sum of blue copper spectrum and arsenic violet that will produce the well known paris green blue, the effect could be emulated using copper carbonate and copper oxide in same composition.

[Crazy Swede]

Paris green blue is a sum of blue copper spectrum and arsenic violet that will produce the well known paris green blue, the effect could be emulated using copper carbonate and copper oxide in same composition.

That was interesting and new information to me!

 

Is there any documented proof for that?

 

If you look at the two overlapping spectra in figure 4 in "An Experimental Comparison of Selected Blue Flame Pyrotechnics" (DOI: 10.1002/prep.202000114, where the spectra from a paris green composition is shown together with a copperoxychloride composition) I cannot see, or understand, any evidence for that...

 

And how do you mean a combination of copper carbonate and copper oxide could emulate it?

In a properly formulated composition, both could give a nice blue flame.

Edited December 26, 2022 by Crazy Swede

[Crazy Swede]

...Item Hardt Blue #6

This is high in sulfur and uses potassium perchlorate. Sulfur (acid forming) seems to be an issue with chlorates. Is the stability issue with perchlorate and sulfur that much better? Do you have any information on the same formula with ammonium perchlorate other than thePihko BSP #4?...

Sorry for cluttering up this thread but I forgot this question.

 

Combining potassium perchlorate with sulfur gives less problems with stability, compared to potassium chlorate, but you still have a rather friction sensitive composition. That said, potassium chlorate can be used with sulfur if the latter is non acidic but then you are playing at a much higher risk level. Personally, I would not do it without adding some kind of pH buffer, like MgO or a suitable carbonate!

 

Sulfur is a great fuel since it scavenges the potassium and therefore sets chlorine free that otherwise would have been lost as KCl.

 

Maybe, and just maybe, arsenic has the same effect by combining into potassium arsenide or arsenite, in paris green based compositions, and therefore providing the copper with chlorine even though there is no other chlorine donor than potassium chlorate. This is just my own hypothesis!

Edited December 26, 2022 by Crazy Swede

[kingkama]

That was interesting and new information to me!

 

Is there any documented proof for that?

 

If you look at the two overlapping spectra in figure 4 in "An Experimental Comparison of Selected Blue Flame Pyrotechnics" (DOI: 10.1002/prep.202000114, where the spectra from a paris green composition is shown together with a copperoxychloride composition) I cannot see, or understand, any evidence for that...

 

And how do you mean a combination of copper carbonate and copper oxide could emulate it?

In a properly formulated composition, both could give a nice blue flame.

In the 1800 the only way to prove that someone was poisoned using arsenic Is to analize oganic fluid using a flame Which burns in Indigo color, so the supposed superiority of green Paris as donor of the blue flames It comes from the sum of the two spectra. The use of carbonate and oxide simulate Paris green due to the property of carbonates to absorb oxygen and lower the temperature of the flame. In fact, much more is used for magenta than That for the blue

[Crazy Swede]

That sounds like an old hypothesis that most probably is wrong Im afraid.

 

How could carbonates absorb oxygen?

[kingkama]

That sounds like an old hypothesis that most probably is wrong Im afraid.

 

How could carbonates absorb oxygen?

If you go to Wikipedia where the flame test of the various substances is treated, the data that I have mentioned is highlighted. reading the writing you reported it is explicitly said that the formula contains green Paris Spectrum analysis of arsenic has been neglected. The carbonate absorbs oxygen because when the structure of the molecule breaks down and releases the carbonate group, this group is transformed into co2 and a co which absorbs part of the oxygen from the oxidizer, lowering the combustion temperature.