Potassium benzoate as star fuel

[Siegmund]

Like it says on the tin.

 

There are several comments on this forum, scattered in various organic-fueled stars threads, about using potassium benzoate as something that doesn't wash out a star with white light like magnalium, but burns hotter than sulfur/hexamine/red gum.

 

Can anyone share any firsthand experience with doing this, or offer any literature references to trying this? Has it given you a good saturated color?

 

I've not come across any articles discussing it, and searching formularies, the only star formulas with potassium benzoate are three decidedly strange-sounding Baechle recipes (and none of them aimed at "intensity" of color - they are in secondary-color formulas.)

 

Also, if someone could send some rain to my part of the country... I may be done with making up fireworks for the season, got stage II fire restrictions starting here tomorrow.

[itwasntme]

I've made some really bright blues with it and ammonium perchlorate. It burns much slower with AP than potassium perchlorate for some reason, although AP tends to do that with most fuels.

 

This kinda thing, such as using a lesser common fuel, I've found to be best to just figure out yourself. There's not much info on esoteric concepts like this online.

 

Keep in mind potassium benzoate has a lower fuel value than traditional fuels, with .69 grams of it being consumed by one gram of oxygen relative to say red gum at .47 or shellac at .42 so use about 1.5x that you would traditional fuel.

[mabuse00]

There are several comments on this forum, scattered in various organic-fueled stars threads, about using potassium benzoate as something that doesn't wash out a star with white light like magnalium, but burns hotter than sulfur/hexamine/red gum.

 

Can tell where?

 

My feeling that potassium benzoate will lead to potassium oxide(?).

An that would rob additional chlorine to form KCl, while hexamine or RG wont do that.

 

Barium-, strontium-, or copper benzoate - different story, they become colourants after working as a fuel so their steal of chlorine can be forgiven.

Edited July 15, 2021 by mabuse00

[Lysdexic]

I've never tried potassium benzoate, what intrigued me about benzoates as a fuel was the ability to also be a color donor. I'm pleased with the results I got with Ned Gorski's rubber star formulas for blue and purple using copper and strontium benzoates in place of lactose. I also used ammonium perchlorate instead of potassium. I didn't record all of the steps or reasons that brought me to the final formula but if anyone is interested:

 

Ned's blue rubber star:

 

Potassium Perchlorate 63

Copper Carbonate 12

Parlon 15

Red Gum 05

Lactose 05

 

Dexy's blue:

 

Ammonium Perchlorate 70

Copper Carbonate 12

Parlon 15

Red Gum 05

Copper Benzoate 10

(does not add up to 100)

 

wet with acetone and screen cut

 

Purple sub 9 parts of the copper carbonate with strontium carbonate and use 5 parts copper benzoate and 5 parts strontium benzoate

 

I'm not sure how balanced it is but I got the burn rate, intensity and color saturation I was looking for.

 

Another reason for responding here is because I'm curious about the compatibility of benzoates and nitrates. I've never seen a composition with a benzoate and a nitrate and knowing pyros if it could be done and it works someone would share it.

Edited July 18, 2021 by Lysdexic

[Siegmund]

I appreciate answers so far. Actual experimentation on hold here until it rains - which may well be September at this rate.

 

@Lysdexic: re nitrate-benzoate compatibility, look at "benzolift" - mixture of whistle and BP to make something more violent than BP but less so than pure whistle (and without chlorate like H3) as a burster. Here is one link to it. Curiously the name 'benzolift' seems to get used regardless of whether you use a benzoate or salicylate whistle.

[itwasntme]

I've never tried potassium benzoate, what intrigued me about benzoates as a fuel was the ability to also be a color donor. I'm pleased with the results I got with Ned Gorski's rubber star formulas for blue and purple using copper and strontium benzoates in place of lactose. I also used ammonium perchlorate instead of potassium. I didn't record all of the steps or reasons that brought me to the final formula but if anyone is interested:

 

Ned's blue rubber star:

 

Potassium Perchlorate 63

Copper Carbonate 12

Parlon 15

Red Gum 05

Lactose 05

 

Dexy's blue:

 

Ammonium Perchlorate 70

Copper Carbonate 12

Parlon 15

Red Gum 05

Copper Benzoate 10

(does not add up to 100)

 

wet with acetone and screen cut

 

Purple sub 9 parts of the copper carbonate with strontium carbonate and use 5 parts copper benzoate and 5 parts strontium benzoate

 

I'm not sure how balanced it is but I got the burn rate, intensity and color saturation I was looking for.

 

Another reason for responding here is because I'm curious about the compatibility of benzoates and nitrates. I've never seen a composition with a benzoate and a nitrate and knowing pyros if it could be done and it works someone would share it.

Benzoates and nitrates just don't burn very well together, at least not without a stronger oxidizer such as perchlorate.

[Twesla]

I appreciate answers so far. Actual experimentation on hold here until it rains - which may well be September at this rate.

 

@Lysdexic: re nitrate-benzoate compatibility, look at "benzolift" - mixture of whistle and BP to make something more violent than BP but less so than pure whistle (and without chlorate like H3) as a burster. Here is one link to it. Curiously the name 'benzolift' seems to get used regardless of whether you use a benzoate or salicylate whistle.

I believe its because it was originally made with benzoate whistle mix so its only natural to assume that a salicylate mix would work, too. That and theyre both aromatic compounds containing a benzene ring.

[Lysdexic]

I appreciate answers so far. Actual experimentation on hold here until it rains - which may well be September at this rate.

 

@Lysdexic: re nitrate-benzoate compatibility, look at "benzolift" - mixture of whistle and BP to make something more violent than BP but less so than pure whistle (and without chlorate like H3) as a burster. Here is one link to it. Curiously the name 'benzolift' seems to get used regardless of whether you use a benzoate or salicylate whistle.

 

I forgot about benzolift, thank you. I hope you get some rain soon and not just for the sake of pyro. We've had too much rain, but we needed it. I look forward to seeing what your experimentation produces.

 

Benzoates and nitrates just don't burn very well together, at least not without a stronger oxidizer such as perchlorate.

 

Thank you. I had no desire to find out the hard way if the combination was dangerous. The idea of oxidizer and fuel both being color donors was interesting but if it worked it would surely be used already. I think I'll just do some homework on the blue and purple I use. Others have already listed oxygen, fuel and chlorine values for all the common compounds we use. No way I could write the equation for everything that takes place when the star burns but should be able to tweak things a bit.

[rellim]

FireworksCookBook lists 19 star formulas with around 5% potassium benzoate, all but one due to Baechle. Only three have any metal, a small percentage of spherical Al. I made a few grams of the green #4 and it looked ok shot from a star gun.

 

Seems likely the KBenz is a substitute for metal. The orange compositions have some charcoal and a lower percentage of Kbenz, probably due to calcium present in charcoal.

Edited July 21, 2021 by rellim