14 replies to this topic

[Potassium chlorate]

I have seen a formula, called the Rossi formula, for H3:

Potassium chlorate 80
Charcoal, airfloat 10
Lampblack 10

Is this more powerful than H3 with only charcoal?

I have also seen "Shimizu bursting charge #46" with potassium perchlorate instead of chlorate, lampblack as the only fuel and potassium dichromate as a catalyst; 70:30+5. This one is said to be one of the most energetic KP burst charges there is, though I fear the poisonous effect of KDK more than I fear the slightly higher sensibility of potassium chlorate in mixtures with no incompatibels.

[Peret]

Lampblack occasionally contains traces of acid and dog-knows-what other impurities so I would not store an H3 made with it, just in case it decided to go off on its own. I would be surprised if the K-dich had much effect on a chlorate - it's used more often for its catalytic effect with perchlorate. Heavy metal oxides are catalytic with chlorates.

[Potassium chlorate]

Lampblack occasionally contains traces of acid and dog-knows-what other impurities so I would not store an H3 made with it, just in case it decided to go off on its own. I would be surprised if the K-dich had much effect on a chlorate - it's used more often for its catalytic effect with perchlorate. Heavy metal oxides are catalytic with chlorates.

Ah, I have used KDK with potassium chlorate but with very little effect. Have to try it with perchlorates some day.

Though I also tested potassium chlorate with manganese dioxide, and made flash with it, and I couldn't see any improvement in just a few grams anyway. Though maybe it might need very intimate mixing?

H3 with lampblack doesn't sound like a very good idea anyway, then. Maybe H3+5% manganese dioxide instead? The catalytic effect might turn out better with H3 than with flash(?)

[Mumbles]

Out of curiousity, why would you need to strengthen H3? On it's own with decent charcoal it should be plenty strong enough to break most smaller shells, and lift smaller ones.

I don't know about acid specifically (though wouldn't be surprised), however I've heard that it more contains sulfur compounds, which are not something I'd want to be sieving with chlorate and then tapping on in a shell.

[Potassium chlorate]

I think that H3 on rice hulls and cotton seeds respectively is a bit "weak" no matter the fact that my charcoal is very good (not the BBQ anymore but real vineyard charcoal). I think that pulverone H3 might also do it, but it might also be too strong. I always want my bursts as powerful as possible without crushing the stars or ruining the ignition of them. Improved H3 on rice hulls or cotton seeds might be just right. But if someone has tried pulverone H3 with success I'd be glad to hear about it.

Edited by Potassium chlorate, 12 January 2011 - 08:14 PM.

[Peret]

The manganese dioxide will lower the initiation point of the composition, but once it lights up there will be no difference. Do take care though. In my misspent youth I made a sodium chlorate composition with manganese dioxide that ignited at or below 100 degrees C, even when damp.

[Potassium chlorate]

Oh, better to leave the manganese dioxide out, then.

But has anyone tried pulverone H3? I heard about it on Youtube, but of course that is no trustworthy source at all.

[RFD]

If H3 could be improved i think somebody would have done it by now, hand mixed H3 is inferior to milled H3( i am definitely not suggesting milling H3 to anybody either,before the "blow yourself up",brigade start),the criteria for good H3 burst is the same as BP burst,get the right amount on what ever carrier you choose and make sure it is really dry,seeds and rice crispies etc,etc,can take a surprisingly long time to dry through to the centre,a poor break still lights your stars,might not look very good but you do see something for your effort,trying to squeeze the last out of your burst will more than likely turn your hardworked shells into maroons=frustration!!.

[AdmiralDonSnider]

Out of curiousity, why would you need to strengthen H3? On it's own with decent charcoal it should be plenty strong enough to break most smaller shells, and lift smaller ones.

Mumbles is definately right on that one.

I think that H3 on rice hulls and cotton seeds respectively is a bit "weak" no matter the fact that my charcoal is very good (not the BBQ anymore but real vineyard charcoal).

Shimizu stresses the fact that the burn rate of H3 is largely dependent on the kind and particle size of the charcoal. Grapevine charcoal is nothing bad, but I wouldn´t rate it among the fastest things out there. The original formula calls for hemp charcoal, which itself is a replacement of paulownia if you read Shimizus notes in the materials chapter of fast. Something in this class is needed. Paulownia has been proved to be a top-performer in BP; willow and similarly reactive types should work well.

I prescreen both the chlorate and the paulownia charcoal (separately) through a fine mesh. Then I hand-mix on a sheet and screen as usual. My charcoal could definately be finer, but I never found my H3 to be too weak. If you wish to tune it, you can still use ballmilled charcoal in screening.

I wouldn´t be surprised if your complaints are a result of a suboptimal coating of the carrier materials. For optimum result you do not only want a simple coating, but a known ratio of the burst comp to the hulls, e.g. 4:1 for small shells like 3". In contrast, if there´s not enough combustible material, the break will be less powerful of course. The pasting also needs to be sufficient for hard breaks, even if H3 doesn´t require much layers.
Granulated ("polverone type") H3 is something you don´t want to use in ordinary sized shells; it probably works well in festival balls and less than 2" shells though.

[Potassium chlorate]

Hm, I use it in relatively big shells too. I used 4:1 H3 on rice hulls and 52:48 H3 on cotton seeds in 6". Both were very good, but in 5" and smaller, I found it a bit lame.

[AdmiralDonSnider]

H3 on hulls in 6" shells? I can´t speak based on experience, but I wouldn´t be surprised if H3 on hulls shatters everything if used in shells larger than 4". They have a huge break chamber compared to 3", and even this tiny amount of space filled with H3 coated hulls suffices to produce big booms.

[Mumbles]

I broke a 6" shell with H3 on hulls once. I don't remember which is which. One is 4:1 H3 on hulls, presumably using generic commercial airfloat, and the other was very coarse milled BP polverone made with the same charcoal and dusted with slow flash. I'd guess the blue one was the H3. A little lopsided, but close to spherical.

[Potassium chlorate]

H3 on hulls in 6" shells? I can´t speak based on experience, but I wouldn´t be surprised if H3 on hulls shatters everything if used in shells larger than 4". They have a huge break chamber compared to 3", and even this tiny amount of space filled with H3 coated hulls suffices to produce big booms.

No, it actually works very good in 6". The red stars here are shattered, but that is due to the fact that they were bound with NC-laquer, which was impured by water, so that they became porous inside, when the water reacted with part of the magnesium in it, not that H3 was too powerful. They were cut, by the way, as were the white. The white are intact but still burn very fast, since they contain 28% magnesium. The green and blue ones were rolled. As you can see, the rolled ones "survive" the burst very well.

http://www.youtube.com/watch?v=YOahKsGNHiM

[AdmiralDonSnider]

Although the shells were very sightly, especially the last one, the explosion flash seems to be quite large, suggesting that some break energy was wasted. I´m not sure how many layers of which material you were using, but it seems that the layers were insufficient. Sufficient layers, on the other hand, may have blown your stars blind. Only speculating.

Purely academic though, that´s a viable approach...

[Potassium chlorate]

Although the shells were very sightly, especially the last one, the explosion flash seems to be quite large, suggesting that some break energy was wasted. I´m not sure how many layers of which material you were using, but it seems that the layers were insufficient. Sufficient layers, on the other hand, may have blown your stars blind. Only speculating.

Purely academic though, that´s a viable approach...

No, I think you're right there.

I used 12-14 layers of gummed tape for 5" and 16 layers for 6", if I remember correctly, i.e. a little less than usually recommended.

But last year I had more layers, which resulted in most stars shattered.

Since most of my stars are chlorate stars, I prefer H3 as a burst and also H3+Al+Si as a prime. Simple and pretty reliable system. Though I have also considered corned BP as a burst and microstar prime as a prime (potassium perchlorate 70, red gum 20, silicone10). That prime was actually used for the white ones, that were Bleser White Magnesium, withouth any chlorates and perchlorates in the composition itself.