Undesired Orange Color in Stars

[hindsight]

In stars that are blue or magenta, I have a problem with unintended orange flame interspersed with the intended color. The affected stars have in common the following chemicals: Potassium Perchlorate, Phenolic Resin, CuO, Parlon and are bound with Absolute Ethanol. I have read Mumbles' statements that Sodium contamination of comps results in this coloration, but this Perchlorate (without anti-cake) is from Hobby Chemicals and is reported to be pure. The stars are tested on the ground and shot into the air 24-48 hours after manufacture and are quite hard. A moderate quantity of Swedish Perchlorate is being shipped , so I will try that to see if the orange disappears, but it may be a while. You will probably tell me it's Sodium contamination (from the Perc), but is there any other possible problem?

[Sparx88]

I get my perc from him too but I get the chinese with anti-cake, no problems with it. I would say it's the parlon giving a yellow/orange color to your stars. If you mix 1 gram of perc with 1 gram of parlon and burn it it will burn yellow/orange.

Edited June 30, 2014 by Sparx88

[nater]

Parlon burns with a reddish orange flame and adds some dross, especially if it is not well screened. Screening out the coarse pieces or using another chlorine donor like saran or PVC might help your color.

[pyrokid]

I'd try a traditional red gum fueled comp bound with dextrin to eliminate the phenolic resin as a source of impurities. You could try a chlorate blue star to see if it's your KClO4 that's causing the trouble

 

I'm not sure that the color of a parlon/KClO4 flame is an indication of impurities there. There are no colorants to be stepped on in that mix.

[nater]

Red gum also burns with a reddish flame. My experience has been that phenolic resin gives superior colors to red gum as well.

[Mumbles]

This might not actually be a problem with purity of chemicals. Rather it could be an issue of formula. To check, you'll have to be relatively close to a burning star, or maybe zoom in with a video camera. There is a common issue of blue stars turning red/orange on the edges of the flame envelope. The desired color emitting ion is CuCl. The red/orange one is CuOH or CuO. This usually happens due to a fuel imbalance.

 

Coarse parlon for me has always left an incandescent tail in the air, and ash on the ground, but never really effected the color of the star too much. It's been a while since I left any in a star, so I might just not be remembering very well.

[hindsight]

All the suggestions are greatly appreciated. Mumbles, thank you for the education about the relevant light-emitters.

 

The Magenta was the Veline formula and the blue was Shimizu #49/70. In both formulas, the red gum was replaced with phenolic 1:1. The parlon was a fine powder from a reputable chem supplier and everything (except the MgAl) went through a 40 mesh screen.

 

Nater, I will try substituting Saran for the Parlon as it is something that aroused my interest. http://www.amateurpyro.com/forums/topic/3943-substitution-of-parlon-with-saran-resin/.

 

The phenolic has not caused a problem before, so I will exclude that as a likely problem. Going back to Dextrin, or using Chlorate is not an option.

 

Sparx, the orange color also appeared when using the Hobby Chem with anti-cake.

 

 

Your help, as always, is great.

[krakra]

Blue copper flames often have yellow-orange corona. It comes from species of copper, do not blame sodium on it. First, make sure that your composition has oxygen deficiency of 10-20%. Second, make sure it burns not hotter than 1000 C, otherwise the color WILL degrade. I also believe it is better to move from metal fuels and parlon/PVC mixtures, in such environment they WILL produce carbon particles that will inevitably produce yellow thermal emission. (actually, copper oxide particles if present may produce yellow emission as well) When I needed blue flame, I got an excellent result with KClO4/(NH4)2CuCl4*2H2O/Polystyrol (if I remember right, 12/3/2 mix, original mix used KClO4/(NH4)2CuCl4*2H2O/stearin/asphalt mix) bound with dichloromethylene. It still had pale yellowish corona, but it was not easily observable. Unfortunately, is also produced surprising amount of smoke, but left no residue and produced no sparks.

Edited June 30, 2014 by krakra

[Sparx88]

All the suggestions are greatly appreciated. Mumbles, thank you for the education about the relevant light-emitters.

 

The Magenta was the Veline formula and the blue was Shimizu #49/70. In both formulas, the red gum was replaced with phenolic 1:1. The parlon was a fine powder from a reputable chem supplier and everything (except the MgAl) went through a 40 mesh screen.

 

Nater, I will try substituting Saran for the Parlon as it is something that aroused my interest. http://www.amateurpyro.com/forums/topic/3943-substitution-of-parlon-with-saran-resin/.

 

The phenolic has not caused a problem before, so I will exclude that as a likely problem. Going back to Dextrin, or using Chlorate is not an option.

 

Sparx, the orange color also appeared when using the Hobby Chem with anti-cake.

 

 

Your help, as always, is great.

 

 

Your right it does, so I'm thinkin since both the chinese and the high purity percs have that issue, it would seem it would be something other than the percs. Since parlon imbues a yellow/orange with both percs and that it is the common item. Hope we can get this figured out because I would like to know how to reduce that effect also. I'm using hobby chem Pergut parlon.

[pyrokid]

I use HCS Pergut parlon in my favorite blue composition and I have no trouble whatsoever.

[Arthur]

Way back in 50AE's posts he did the theory and practise of blue comps, with all the oddities to preserve good colour. You may find it good reading.

[hindsight]

Arthur, I looked under 50AE's topics and posts and couldn't find the posts you mentioned.

 

Today, made the Shimizu blue stars again, stiil using phenolic resin and ethanol , but substituted Saran for the Parlon, and used Swedish perchlorate instead of Chinese. When they are dry, I will report if the orange flame component persists.

[LambentPyro]

All the suggestions are greatly appreciated. Mumbles, thank you for the education about the relevant light-emitters.

 

The Magenta was the Veline formula and the blue was Shimizu #49/70. In both formulas, the red gum was replaced with phenolic 1:1. The parlon was a fine powder from a reputable chem supplier and everything (except the MgAl) went through a 40 mesh screen.

 

Nater, I will try substituting Saran for the Parlon as it is something that aroused my interest. http://www.amateurpyro.com/forums/topic/3943-substitution-of-parlon-with-saran-resin/.

 

The phenolic has not caused a problem before, so I will exclude that as a likely problem. Going back to Dextrin, or using Chlorate is not an option.

 

Sparx, the orange color also appeared when using the Hobby Chem with anti-cake.

 

 

Your help, as always, is great.

Hindsight I have experienced the same issue with the Shimizu formula. I tried subbing the Parlon for Saran and got a flickering ghost star. The Blue would pop up and flicker and would have an orange red color on the edge of the flame sometimes. It was a real weak color so I switched to Pyro Science Blue and I love it.

 

Dylan

[hindsight]

LambentPyro, Assume you meant you used Saran instead of the listed Parlon.

I replaced the Parlon with Saran and used Swedish perchlorate instead of Chinese perchlorate in the last attempt to get Shimizu's formula to get a pure blue. After 24 hours (which is usually long enough using ethanol/phenolic resin for binding my stars) the stars were not very hard. Burn testing them on the ground gave a sputtering flame and some orange was present. The test was premature,

but Parlon, used previously with the cheaper perchlorate, performed better than Saran with Swedish perchlorate. The Saran stars will be tested again after they are completely dry.

[Sparx88]

After messing around I agree that the pergut brand parlon is fine.

Here is a blue recipe mumbles came up with for me using the chems I have and it's a nice deep blue, not that baby blue crap. Give it a try.

 

P.Perch 62

sulfur 18

black copper oxide 12

parlon 4

dextrin 4

optional - alum,magnal 5

Edited July 3, 2014 by Sparx88

[hindsight]

LambentPyro, Assume you meant you used Saran instead of the listed Parlon.

I replaced the Parlon with Saran and used Swedish perchlorate instead of Chinese perchlorate in the last attempt to get Shimizu's formula to get a pure blue. After 24 hours (which is usually long enough using ethanol/phenolic resin for binding my stars) the stars were not very hard. Burn testing them on the ground gave a sputtering flame and some orange was present. The test was premature,

but Parlon, used previously with the cheaper perchlorate, performed better than Saran with Swedish perchlorate. The Saran stars will be tested again after they are completely dry.

Shot these stars today after they seemed dry (they were ethanol Pinball primed yesterday) and the orange flame was still mixed in the blue color. They lit and burned well but the purity of colour was a failure. Looks like I will try Sparx88's formula from Mumbles.

[Mumbles]

I have to give credit, where credit is due. The formula above is Hardt Blue #6 with a couple of simple substitutions. I've included the original for reference. I just suggested a few simple changes based upon what Sparx88 had available.

 

Potassium Perchlorate 62

Sulfur 18

Copper Oxychloride 12

Dechlorane 4

dextrin 4

 

Given the success of my substitutions I suspect that most common chlorine donors would work based upon what is available. In other formulas I've essentially used Copper oxide, oxychloride, and carbonate basically interchangeably. Oxide is my personal favorite.

 

I'm not sure what to tell you if you'd like to use phenolic resin to bind this star. I guess try to replace the dextrin 1:1, but I'd also make a water bound control batch. It's kind of hard to make a good suggestion. Normally you'd just replace part of the fuel, which is sulfur here. There is the caveat that sulfur also makes the perchlorate give up some of it's chlorine to help with the blue color. Sulfur will also have a lower fuel value I believe, so a 1:1 substitution wouldn't be suitable.

 

If you find you need more than 4% phenolic resin, maybe try something like the following. I tried to balance out the fuel value, as well as increasing the chlorine donor.

 

Potassium Perchlorate 62

Sulfur 12

Copper Oxychloride 12

Chlorine Donor 7

Phenolic Resin 7

[nater]

Jim Widmann recommends 7% phenolic resin for binding. That would shift the comp slighty richer in fuel of you replaced the dextrin.

[Jakenbake]

I really like the looks of that formula. Given sulfur is about the coldest easily accessible fuel around. Definitely going to have to give that one a try.

[Niladmirari]

 

Potassium Perchlorate 62

Sulfur 18

Copper Oxychloride 12

Dechlorane 4

dextrin 4

 

Is it possible to add in the composition 5% MgAl (200 mesh) to increase brightness? And replace copper oxychoride on CuO.

[Mumbles]

Is it possible to add in the composition 5% MgAl (200 mesh) to increase brightness? And replace copper oxychoride on CuO.

 

 

You didn't read the thread at all, did you? You may want to glance at post 15.

[hindsight]

.....

Potassium Perchlorate 62

Sulfur 12

Copper Oxychloride 12

Chlorine Donor 7

Phenolic Resin 7

 

Greatly appreciate the suggestion. I will try it and report back.

[Niladmirari]

 

 

You didn't read the thread at all, did you? You may want to glance at post 15.

Sorry, did not notice.

 

What do you think. Possibly use hexamethylenetetramine instead of sulfur?

[hindsight]

 

Greatly appreciate the suggestion. I will try it and report back.

Okay used the formula:

 

KClO4(Swedish) 62

Sulphur 12

CuO 12

Parlon 7

Phenolic resin 7

Solvent absolute ethanol

 

The stars were cut and pinball primed yesterday and are hard and dry. On the ground there is still some persistent orange flame but they are a pretty blue in the sky. They burn a lot faster than the Shimizu formula used earlier in this thread. (In fact, the first mine using the usual number of stars was more like a salute with no stars launched. Subsequent mine with fewer stars was fine).

[Mumbles]

I think I found the posts from 50AE that were being referred to before.

 

http://www.amateurpyro.com/forums/topic/6756-fuel-value/

 

One on phenolic in general. A fuel value is calculated based on the formula in the title.

http://www.amateurpyro.com/forums/topic/6379-phenolic-resin-c48h42o7/

 

If you look at the numbers, you'll find that phenolic resin has a stronger oxygen demand than sulfur, so you only need .415g of phenolic resin to replace 1g of sulfur. You'll also need .53g of phenolic resin to replace 1g of dextrin. It looks like I over estimated the fuel some, which might be to blame for the slight orange halo. Replacing 4g of dextrin and 6g of sulfur would only require 4.61g of phenolic resin total, plus whatever additional fuel value the extra parlon adds. You do want the flame somewhat fuel rich, but not too much.