36 replies to this topic

[FlaMtnBkr]

Hi everyone,

I have read many times that barium chlorate and shellac gives one of the best green colors around. However, I have never seen how to make the stars other than the chemicals and ratio used. Are they wetted with alcohol to use the shellac as a binder? I have read some horror stories of using shellac as a binder so I'm hesitant on doing this and ending up with a puddle of sticky composition. I would like to use a star pump or the screen cutting method for these or regular cut stars if I have to. I even thought about using NC to bind them but NC burns with a pretty bright yellow flame and I don't want to add something that will take away from the color. I have also read of substituting red gum for the shellac. Would this make anything easier and is the color as good as using shellac? I also thought about making some thin 'tubes' with a wrap of gummed tape and folding one end over to make a cup and pour them full of the comp to use as a rising effect or stick a nail in the center and seeing if it would work as a go getter.

If anyone has used this formula and had good results could you outline your process? Sorry for a ton of questions but any input would be greatly appreciated!

PS I hope this is the best forum for this

[Peret]

I have used shellac with a chlorate/paris green star, and it was probably my horror story you read. My error was not realizing that only the 10% shellac was going to take up the alcohol. I just sprayed it into the dry mixture the way I would add water to a dextrin star and consequently ended up with far too much, so that the whole mixture turned to liquid. It probably only needed one or two percent, but that would have made an awfully dry sandy mixture at first until the shellac dissolved (it takes its time). The resulting mixture would be sticky as hell and there's no way I would use it with my star plate, as I'd never get it clean after. These are for cutting.

Later I made greens with 85% barium chlorate and 15% red gum, plus a few percent dextrin and bound with water. The color was excellent and they pumped without any problems.

[Potassiumchlorate]

I love barium chlorate, but I have had trouble with binding with shellac and red gum too.

Recently I made this composition:

Barium chlorate 84
Shellac 10
Dextrin 4
Chlorowax 2

They are pumped. The chlorowax is to make them slide off the pump gently and not stick. Stearin could be used as well. They certainly don't need the extra chlorine.

[FlaMtnBkr]

Has anyone tried barium chlorate and lactose? I was wondering if the shellac could be replaced with lactose and searched and I found a formula from the 19th century that used the 2 with dextrin. I assume with the dextrin it was dampened with water and it's not just an auxillary fuel. The formula I found is:

20 barium chlorate
7 lactose
1 dextrin

[warthog]

How do you ignite your Ba(ClO₃)₂ stars? They are not so easy to get going. Especially in a hard break. The green produced is a nice one for sure but the trouble with igniting them is making this project hard to make work for me.

[californiapyro]

step prime? oh although it has to be sulfurless. how about veline superprime step-priming? thats a nice hot sulfurless one.

[Potassiumchlorate]

How do you ignite your Ba(ClO₃)₂ stars? They are not so easy to get going. Especially in a hard break. The green produced is a nice one for sure but the trouble with igniting them is making this project hard to make work for me.

I use KP prime with silicon. The ones above I primed with pinball prime.

I have another composition, though, which ignites pretty easily, but it's a bit "over the top":

Barium chlorate 68-70
Magnesium <63µm 12
Parlon 12
Red gum 6-8

The parlon is just there as a binder and inhibitor for reactions with the magnesium, of course. This one is deeper than anything with barium nitrate but brighter than organic barium chlorate greens.

[Peret]

I rolled mine in Veline prime when they came out of the pump, then later when they were dry I coated them in my standard hot prime - 20% mill dust, 40% KNO3, 40% silicon, +5 dextrin. I always had trouble getting barium green stars to light until I started using the silicon prime. Barium (nitrate or chlorate) needs a substantially hotter flame than potassium to get it started.

[Potassiumchlorate]

I primed mine twice as well. I added dextrin to the pinball prime, so it was first bound with the dextrin, when they were pumped. Then I added more prime by spraying isopropanol on them and sprinkling the prime over them, so another layer was bound with the red gum.

[warthog]

Thanks! I have some more Ba(ClO₃)₂ inbound now. Should be here just after Christmas.
I suppose next year is the year I will have my best Reds & Greens ready for the season since I started to late this year to get it done.

[Mumbles]

Quite often people will replace part of the barium chlorate with either potassium chlorate and/or barium nitrate. This solves several of the problems people have mentioned here. The stars tend to light easier, and stay lit, as well as burning more rapidly. Despite it's reputation for sensitivity, barium chlorate is still a relatively sluggish oxidizer. The sensitivity and of course cost are also reduced. Hardt #1 and #2 are supposed to have excellent colors while taking advantage of the aforementioned benefits.

http://www.pyroguide...Stars_(Organic)

Note: Hardt #2 does NOT have 28 parts charcoal in it. It should be 4 parts. The binding instructions are also not directly from Hardt, but some aqueous system should be used. IE. You can use straight water if you'd like.

[Potassiumchlorate]

Look at the shell competition thread. I have posted videos of the two shells made with barium chlorate stars I shot on NYE there. With pinball prime+5% silicon I managed to get almost every single star thoroughly lit. Like I said: one layer bound with dextrin, then when, the stars were completely dry, another layer bound with red gum and isopropanol as solvent. The burst charge was H3 on cotton seeds.

[Potassiumchlorate]

By the way: I know that my stars burned a few seconds too long. 20mm is a bit too big for a 6", but it was also partly due to the delay fuse burning too long, making the shells starting to fall down a bit again before the burst.

At least half of the shellac could probably be replaced by red gum to speed up the burning a bit. I don't like the idea of adding potassium chlorate for a faster burning, since this will impure the colour a bit.

Stochiometrically a mix of only barium chlorate and shellac, where the C burns to CO₂, should be 88:12. Barium chlorate and red gum should be 86:14. Since I used dextrin as the binder and added 2% chlorowax for making the stars slide off the pump easily, I could barely have had much more than 84% barium chlorate in the stars anyway. I think probably no less than 10% and definitely no less than 8% shellac or red gum is needed to get a really "pure" flame.

Edited by Potassiumchlorate, 10 January 2012 - 10:16 AM.

[Mumbles]

I'd gladly take the ease of mind using a formula utilizing potassium chlorate and/or barium nitrate. Straight Barium Chlorate/Shellac stars have been known to explode from the force of lift on occasion. For that reason alone, I'd never use the "pure" mix for anything but lance. I don't know all the conditions surrounding those incidents however. Perhaps you could do a few small scale tests for us to find out if adding anything else has that big of an impact? I'd be interested in knowing what sort of effect adding other oxidizers would have.

[Potassiumchlorate]

I think it's simply impurities in the barium chlorate making it. "Good" barium chlorate is a bit coarser than talkum powder but much finer than table salt (<125µm), dry (partly airfloat), doesn't cake and doesn't smell; that is my pretty unscientific observation.If you get barium chlorate with many visible crystals, a feeling that it is moist and caking, it's most probably impure.

I have tested Ofca Emerald Green and Lancaster Green pumped before. They are nice in colour, probably better than anything based on barium nitrate or carbonate, but not really as "deep" as with barium chlorate alone.

Edited by Potassiumchlorate, 10 January 2012 - 11:39 AM.

[Potassiumchlorate]

Has anyone tried barium chlorate and lactose? I was wondering if the shellac could be replaced with lactose and searched and I found a formula from the 19th century that used the 2 with dextrin. I assume with the dextrin it was dampened with water and it's not just an auxillary fuel. The formula I found is:

20 barium chlorate
7 lactose
1 dextrin

Shiedlovsky (I think the spelling is correct) states that 88% and 12% iditol (sorbitol) gives a very good green. I have tried with sorbitol, but it's hard to say whether this is better than shellac or not. It burns very fiercfully, anyway.

I prefer shellac myself. The ideal for me would be to roll stars with 88:12 (stochiometrically burns all carbon to CO₂) barium chlorate/shellac, using isopropanol as a solvent. I have done it one a smaller scale before. Might be worth trying again. It's more difficult than binding with dextrin or SGRS, though.

Edited by Potassiumchlorate, 13 January 2012 - 06:22 AM.

[Essohbe]

Hey all, I have a question.

You ever bind with saran resin? I reload 37mm and 26.5mm munitions and since I love green I wanted to reload the green flares. I wondered what would be the best thing to use that would give a bright rich green that burned well.

I have played around with Ba(ClO3)2 using sucrose as a binder + fuel but it's not as green as I would like so figured maybe some metals would give it a better color (Mg or Al) and just bind it with saran?
I do have some old atomized spherical Al, would it ignite you think? If not I have the usual Al dark. Ideally I want Mg flakes. Any suggestions are welcome.

I know it's hard to ignite too, I haven't shot one yet. I use FFFg powder for propulsion/lift (it's in a munition tube fired from a gun). It's always been hot enough to ignite the fused payload tube I make which are mostly all smoke/gas rounds. Would I have to prime the compositon around the fuse inside the payload tube to ensure ignition? Sometimes I just stick BP or matcheads in the smoke rounds to ensure ignition.

[Potassiumchlorate]

I have made stars with barium chlorate and magnesium. They become easier to ignite and brighter but you lose colour depth instead.

I don't think saran will work. I have tried parlon and PVC as only fuels, and they wash out the colour. I don't have a clue why, though.

[dave321]

Shiedlovsky (I think the spelling is correct) states that 88% and 12% iditol (sorbitol) gives a very good green. I have tried with sorbitol, but it's hard to say whether this is better than shellac or not. It burns very fiercfully, anyway.

I prefer shellac myself. The ideal for me would be to roll stars with 88:12 (stochiometrically burns all carbon to CO₂) barium c.

chlorate/shellac, using isopropanol as a solvent. I have done it one a smaller scale before. Might be worth trying again. It's more difficult than binding with dextrin or SGRS, though.

iditol is not sorbitol .

iditol is a resin (melamine type ?) mentioned by shidloskvy in "fundamentals of pyrotechnics"
used as a binder in magnesium flare systems.

dave

[Potassiumchlorate]

Hm, weird. Wiki must be wrong this time or there must be different substances called iditol. Iditol

Same molecular formula and molar mass as sorbitol.