whitefox77 Posted December 9, 2007 Posted December 9, 2007 So I made my first stars last night/this morning. I got the mix off the The PFP Database: Potassium nitrate: 45%Charcoal: 50%Dextrin: 5%25% alcohol for a solvent Maybe it's just that I have crappy charcoal, but these were kind of lame. They just fizzled from one end to the other without producing much light. From more than 20 feet away at night, they were hardly visible at all. I think this might be more useful as a filler or delay mixture. Next I'm going to try the mix below, it's similar to the slow-burn flash I used to ignite the thermite, and that was very bright and impressive. Potassium nitrate: 41%Sulfur: 4%Aluminum: 49%Dextrin: 6%25% alcohol for a solvent If anyone has a recommendation for a simple star mix that is suitably impressive it'd be appreciated. I really only have the chemicals for black powder, smoke mix, and thermite.
pudidotdk Posted December 9, 2007 Posted December 9, 2007 You say nothing about preparation of the stars. Normally charcoal streamers need to be ball milled for good, otherwise they won't burn correctly.Did you press them in to stars or were you just testing a pile of composition?Did you fire the stars from a stargun... if not you should.
whitefox77 Posted December 9, 2007 Author Posted December 9, 2007 I mixed together 100g of material, then ball milled this mix for a couple hours per batch in 3 batches of approximately 33g each (I'm forced to mill in my basement so I keep my batches small to minimize potential accidents). Then I mixed it with the alcohol. About 1/3 of the mix I pressed through a screen to make micro-stars for use in a fountain. (this was the main reason I made this mix) The other half of the mix I spread thickly on wax paper, then put another piece of wax paper on top of it and used a rolling pin to get it down to around 1/4 inch think. I pealed the top piece of wax paper off it, then let this cure in a warm dry area (shelf above a radiator) for 9 hours over night. I then cut/broke this into .5 inch squares. I haven't done anything really with the stars yet. I simply lit the edge of one of them to see what it would look like burning. I'm not even 100% sure what a stargun is (there is a reason I put this in the Newbie section).
tentacles Posted December 9, 2007 Posted December 9, 2007 That is the formula for shimizu's Chrysanthemum of Mystery, I have not seen these stars in person but they should look nice. The thing about charcoal stars is that at least some portion of them must be ball milled. Generally, you would mill all of the ingredients , but never metals, together unless otherwise specified. Charcoal stars almost always look like crap on the ground, must be in the air to look good.
Mumbles Posted December 9, 2007 Posted December 9, 2007 Two problems. #1 The stars arn't dry yet. If you only made them last night, they are not dry at the moment. Give then at least 3-4 days. #2 High charcoal based stars and streamers like these often don't preform the same on the ground as they do in the air. They will fizzle and produce a lot of slag on the ground, but in the air, this is blown off and is what creates the tail.
whitefox77 Posted December 9, 2007 Author Posted December 9, 2007 1: Really? I read that they could dry in as little as 6 hours using alcohol. It was water that made them take days to dry. But I'll take your word for it since you've been doing this a lot longer than me. 2: Getting them "in the air" is going to be a bit of trouble. Any type of aerial firework is illegal in the town I live in unless you have a license. Perhaps when I visit my in-laws in Wisconsin... Well as I said the main purpose for this was for making micro-stars in a fountain (fountains are legal). For that it worked great. For my first try at making fountains I think it was rather impressive (purple/pink flames and gold sparks). Sorry, no pictures or video.
Mumbles Posted December 10, 2007 Posted December 10, 2007 You used pure alcohol? That 25% alcohol doesn't mean 25% by mass alcohol added to the composition. It means that a solution containing 25% alcohol in water was used to wet them(IE 25mL alcohol and 75mL water). Pure alcohol wouldn't activate the dextrin very well, and would probably yield rather crumbly stars.
whitefox77 Posted December 10, 2007 Author Posted December 10, 2007 You used pure alcohol? That 25% alcohol doesn't mean 25% by mass alcohol added to the composition. It means that a solution containing 25% alcohol in water was used to wet them(IE 25mL alcohol and 75mL water). Pure alcohol wouldn't activate the dextrin very well, and would probably yield rather crumbly stars. Huh, no wonder the stars are so crumbly. I was kind of curious about that, I thought they'd be harder. Now I know. I think I also know what to do with my stars, since they do crumble rather well, I'll just finish the crumbling, and use them in fountains. Live and learn
Mumbles Posted December 10, 2007 Posted December 10, 2007 You could also toss them back into the ball mill and rewet them using water to get them properly bound. If they're already pretty crumbly, I doubt they'd be able to survive long enough to make it out of the fountain.
whitefox77 Posted December 10, 2007 Author Posted December 10, 2007 Actually the mix worked quite well for that. The gold sparks shot up about 4 feet then arced back to the ground, most lasted almost all the way to the ground. For my first fountain, I was quite happy. Besides, my mill is going to be quite busy for the next couple days making more charcoal powder.
tentacles Posted December 11, 2007 Posted December 11, 2007 "I was quite happy." That's the point, if you like it, it was successful!
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