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Blue star question..


braddsn

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I must be missing something.. but is there a reason that there are no perc blue stars with MgAl in them? All other colors (like green) have some formulas which contain MgAl. Seems like a little metal would decrease the chances of them blowing out at speed. Could you just add a little MgAl to any of the blue comps (conkling, phiko, etc)?? Could a little MgAl also possibly increase burn speed? Anyone experiment with this?

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While there are a few metallic blues used, the metal fuel often makes the star burn too hot and appear pale. Blues appear better with cooler flame temperatures, so organic fuels tend to work better.
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I believe the hot burning metal tends to wash the color out. Blues are on the lower end of the temp scale and will burn without that deep color if too hot. I'm no expert Brad and if anybody wants to chime in and correct me feel free. Blues are a mystery to me and I've become obsessed with getting them right. I really like the pyro sci blues chained with brilliant white. The contrast seems to make the blue appear deeper. If I ever get a decent camera and figure out how to use youtube I'll start putting up clips of my shells. Some are really pretty and some are just so so, but all of them are fun and exciting to me. Even those little threes. Your breaks on them impress the heck out of me.
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China blue:


Potassium perchlorate 45, copper oxide 22, sulfur 5, magnesium aluminum alloy 5, phenolic resin 7,polyoxyethylene 8, shellac, 1


Potassium perchlorate 53, sulfur 15, copper oxide 16, polyoxyethylene 8, magnesium aluminum alloy 20


Potassium perchlorate copper oxide 45, 25, 8 and 6 of HCB, sulfur, magnesium aluminum alloy 7, phenolic resin 8


Potassium perchlorate, 52% copper oxide 20%, chlorinated paraffin 5%, sulfur 18%, aluminum magnesium alloy2%, Rice noodles 3%


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As others have mentioned, blues tend to be tricky. The copper species in the flame is decomposed at too high of a temperature. The resulting metal species from magnesium and/or aluminum can also be very bright, which further complicates this.

 

Metallic blues can be done. I've had the best luck when keeping the metal content relatively low, around 5% or less. You also have to ensure that plenty of chlorine is available to help mask the Mg and/or Al species.

 

As far as those chinese formulas that were posted, I would take the first two with a grain of salt. #3 and #4 look like possible starting points. I'd leave out the rice noodles though :)

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Mumbles, you and I had a conversation once about adding a small amount (possibly 5%) of MgAl to Pyro Science blue to possibly decrease burn time and increase temp a little. As of right now, I am giving Veline Blue a try. I noticed that it has a small amount of MgAl in it. Burns nice on the ground, so I rolled a 1kg batch and gonna see how they look in the sky. After NUMEROUS firings out of my star test gun, it's true that the blue stars blow out very easily.. or at least the perc based ones. My hopes are that a little MgAl will solve some of that problem, even though they may appear a little more washed out. Give and take.

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See my above post ivars. :)

Ha, sorry, somehow missed that bit ;) It's a nice blue nevertheless.

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  • 1 year later...
I need a help for making blue stars.l have no perchlorate only chlorate,cuo,shellac,cpvc,mgal.I try two or three formula but not blue only light orange colour.
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I need a help for making blue stars.l have no perchlorate only chlorate,cuo,shellac,cpvc,mgal.I try two or three formula but not blue only light orange colour.

mention your formula you tried??

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That formula is a close modification to a perchlorate formula given in Shimizu's FAST. I've used an almost identical formula with good results. It may be the shellac and PVC substitutions. I got the below formula from Dave Stoddard on PML several years ago. There is another similar formula given in Hardt with lactose in place of red gum, though that one does actually call for PVC as the chlorine donor. It sounds like your chemicals may be contaminated perhaps. Blue is the most sensitive color to impurities.

 

 

"In keeping with the practice of remaining on topic for posts,

this is my favorite blue star comp (it is my modification of
a formula originally posted by Shimizu in FAST):
Blue Star
Potassium Chlorate ........ 64.5 %
Red Gum ................... 9.9
Cupric Oxide .............. 13.4
Parlon .................... 5.4
Charcoal .................. 2.0
SGRS (Binder) ............. 4.8

Lights easily, burns fast, good blue color."

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Be advised that SGRS takes considerably longer to 'activate' than does dextrin. So, be prepared to dampen and mix well, then allow it to sit, covered, for at least a couple of hours before you start pressing. Many practitioners will allow SGRS comps to sit overnight after dampening and before processing, but blues might be an exception, due to the possible adverse reactions that can happen in metal-fueled stars.

 

That particular blue, containing no metal, should not demonstrate any adverse characteristics when wet, so I think you can safely let that 'temper' for a time before pressing.

 

Lloyd

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Yes, but it will require a good bit more water, up to as much as 15% (or so). Be careful, and "sneak up" on the moisture content, until you JUST reach cutting consistency. Especially with formulae high in charcoal content (NOT like that one), added water has no apparent effect for up to several minutes (maybe even 1/2 hour), and it's VERY easy to over-wet, thinking there's not enough water in the mix -- until it's too late!

 

Lloyd

Edited by lloyd
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Looking for a (relatively) non-toxic green star formula, I found this on Skylighter:

Potassium nitrate 15
Sulfur 2
Airfloat charcoal 1
Copper powder 4
Red gum 1
Dextrin 1


Doesn't look like it would be green to me. Maybe, slightly blue from copper. Has anyone actually tried it?? Lloyd has indicated he did not think it would be very green.
Edited by vol47
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  • 2 weeks later...

That formula is a close modification to a perchlorate formula given in Shimizu's FAST. I've used an almost identical formula with good results. It may be the shellac and PVC substitutions. I got the below formula from Dave Stoddard on PML several years ago. There is another similar formula given in Hardt with lactose in place of red gum, though that one does actually call for PVC as the chlorine donor. It sounds like your chemicals may be contaminated perhaps. Blue is the most sensitive color to impurities.

 

 

"In keeping with the practice of remaining on topic for posts,

this is my favorite blue star comp (it is my modification of

a formula originally posted by Shimizu in FAST):

 

Blue Star

 

Potassium Chlorate ........ 64.5 %

Red Gum ................... 9.9

Cupric Oxide .............. 13.4

Parlon .................... 5.4

Charcoal .................. 2.0

SGRS (Binder) ............. 4.8

 

Lights easily, burns fast, good blue color."

I am try two time 10gm batch but there no blue.what's going wrong

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Are you binding the formulas as stars or trying to burn them as powders? I can't speak for this formula specifically, but in some instances a powder will burn differently than a bound star. You will also want to ensure that your stars are dry. Moisture can cool things off or change burning behavior.

 

I assume you can make other chlorate colors with good success? This would tend to rule out contamination in any mutual chemicals.

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Mr.Mumbles my stars is dry.I make red color with potassium chlorate.some doubt about my copper oxide it is pure or not.
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While most of the people who responded already explained this, you don't often see blue compositions with metal in them because copper-compound based blues tend to need a lower-heat flame to still appear deep blue. Unfortunately, I would have recommended Conkling Blue, but it has Potassium Perchlorate (KClO4), which you had said you did not have. Anyways, I would suggest blues that do not contain metals, or very little metals (i.e. 1%-3%) for the best results. These would still retain a deep-ish blue, but would have a bit more brilliance than compositions that lack any metals. :)

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