3 replies to this topic

[44RedHawk]

Are there any compatibility issues with Potassium Dichromate (as a catalyst [Shimizu, FAST, pp145] in non-Sulfur Potassium Perchlorate polverone) and Potassium Chlorate based color star compositions? I've made some hot non-Sulfur Perchlorate/K-Dichromate catalyzed polverone as filler powder in my Chlorate color star rocket headers and need to be aware of any potentially dangerous or sensitive compatibility issues for same. Thanks -44RedHawk

[MDH]

Not that I'm aware of aside from your lungs. About a year back I obtained a small amount of it, and I found it didn't catalyze chlorate decomposition at all with simple 1g sugar burn tests. There just wasn't a difference.

Keep it away from highly soluble barium and copper salts is my only advice. I haven't USED it in color star compositions but a quick look at the low solubility of other chromates shows probable DD reactions.

[Peret]

Manganese dioxide is the classic catalyst for chlorates - other heavy metal oxides also work - but be careful, it's easy to make a comp that lights at an unfeasibly low temperature, for example if you just glare at it too sternly.

[seymour]

Generally it's the transition metals that act as catalysts, Iron and Copper salts probably being mos freqient as pyrotechnic catalysts.

However, considering the toxicity of dichromate, and the fact that it's not needed here, I'd save it for coating MgAl and Mg for use with NH4ClO4 (though it might not be good to play with that if you've got chlorate around).

Especially in a polverone form, KP-Charcoal has plenty of power, especially if a good charcoal is used. If you're not getting enough power from it, a bit more pasting is all that's needed.

The only incompatibility I'm aware of is one between many soluble barium salts and K dichromate, as MDH referred to. For example, in a mixture of Ammonium perchlorate, Barium nitrate and Magnesium with K dichromate, you'd have the ions swap in the presence of moisture (to be expected unless it's sealed anhydrous in resin) and get insoluble Barium dichromate (unable to protect the Mg) and some Potassium nitrate, which attracts moisture speeding the reaction.

It's not so much a safety one, but your stars will degrade and be ruined. It would be better to choose Barium carbonate and avoid these issues! Though the resin (Parlon, Resinox both working) way works too in my experience.

Edited by seymour, 05 September 2011 - 06:14 AM.