Green 1 or Green 2 from the spanish PDF?

[dangerousamateur]

Please take a look at the greens but also the blues. They always give 2 formulas.
http://de.scribd.com/doc/70688538/Formulas-Color-y-Tecnica-Empav-1
Did you ever compare them, or can you perhaps tell by locking at the formula what difference they make?

Green 1 is identical to red 2, both contain a mixture from carbonate, nitrate and perchlorate.

Green 2 contains mostly the nitrate and a little perchlorate

Which one gives better color?
Whats the idea of having 2 formulas?


And how about the blues, how do they compare?

 

 

And in general, why do thy use so much perchlorate in their stars?

At least in the reds and the greens?

I found the nitrates alone to be superior, also cheaper. And at least barium nitrate is not hygroscopic.

 

Or is perchlorate cheaper in industrial scale?

Edited February 22, 2014 by dangerousamateur

[spitfire]

perhaps it has something to do with the size of the stars...? Not sure

[ExplosiveCoek]

KClO4 is 2.4 euro/kg and SrNO3 for instance 5 or 6 euro/kg in bulk. So that's why they try to get the best colors out of high % KClO4 based stars. Also KClO4 allows for an easier ignition than SrNO3 or Ba(NO3)2 based comps would.

 

Star size is irrelevant on compo that you use. More or less all the comps have the same burn duration, and star size is only altered when up or downscaling in size of your shell .

 

Now, on your question:

I found the bacarbonate one's to be inferior, when tested as a powder on the ground. I have not tried them as stars in a shell yet and just burned the green powder as scrap IIRC. Overal I found green compositions to be washed out/pale when burned on the ground, when compared to red colors. So no definitive answer here. Guess you gotta mix up 10g or 100g up of each and see which one you like best.

Edited February 23, 2014 by ExplosiveCoek

[Mumbles]

You really can't test star compositions as powder on the ground and expect to get any sort of reliable idea of their color or properties. Tasting cookie dough or cake batter might still be good, but it's vastly different from the finished product.

 

In any case, I find to get good color out of carbonates (especially green), you need a fairly high metal content. Green 1 however doesn't really have a lot of carbonate it in, and has a pretty decent metal content, so I suspect it's just fine.

 

I can't speak with certainty, but perhaps the formulas given are just from two different sources originally. Some manufacturers will use a few versions of each color for various purposes. It's not uncommon to have a fast and slow version of each, or normal and bright versions. In any case, you will notice that for the colored stars there are generally two separate "systems". Red 1, Green 2, Blue 1, Orange 2, Fuchsia 1, and violet all are quite similar, while the others are quite similar to one another.

[Niladmirari]

Also KClO4 allows for an easier ignition than SrNO3 or Ba(NO3)2 based comps would.

How? KClO4 decomposition temperature 650 °C. It is more decomposition temperature Sr(NO3)2 or Ba(NO3)2.

[Mumbles]

It has a lower melting point, which allows it to initiate reactions at a slightly lower temperature. It's also a less sluggish oxidizer than either barium or strontium nitrate. Once the reaction gets going, it tends to stay that way.

[spitfire]

Maybe another approach: at least for me, hygroscopic Strontium Nitrate? I really like ''ruby red'' it's my favorite red. But due to the hygroscopic nature of SrNO3 i can't store the stars or finished items. So i moved to the carbonate reds. Less deep, but easy to ignite and not sensitive to moisture. It's just a practical thing for me.